GM Service Manual Online
For 1990-2009 cars only

Engine Control Module Scan Tool Information LY7

Table 1: Engine Control Module Scan Tool Data
Table 2: Engine Control Module (ECM) Scan Tool Output Controls

The Engine Control Module Scan Tool Data List contains all engine-related parameters that are available on the scan tool. The list is arranged in alphabetical order. A given parameter may appear in any one of the data lists, and in some cases may appear more than once, or in more than one data list in order to group certain related parameters together.

Use the Engine Scan Tool Data List only after the following is determined:

    • The Diagnostic System Check - Vehicle is completed.
    • No diagnostic trouble codes (DTCs)
    • On-board diagnostics are functioning properly

The scan tool values from a properly running engine may be used for comparison with the engine you are diagnosing. The Engine Scan Tool Data List represents values that would be seen on a normally running engine.

Important: A scan tool that displays faulty data should not be used. The scan tool concern should be reported to the manufacturer. Use of a faulty scan tool can result in misdiagnosis and unnecessary parts replacement.

Only the parameters listed below are referenced in this service manual for use in diagnosis.

Engine Control Module Scan Tool Data

Parameter

System State

Expected Value

Description

Base Operating Conditions: Engine Idling/Radiator Hose Hot/Park or Neutral/Closed Loop

5-volt Reference 1 Circuit Status

--

OK

This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present.

5-volt Reference 2 Circuit Status

--

OK

This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present.

5-volt Reference 3 Circuit Status

--

OK

This parameter will display OK if the circuit is good or Fault if a short to ground, short to B+ or open circuit is present.

A/C Disengage 1-8 History

A/C ON

Reason for A/C Disengagement

The parameter displays the last 8 air conditioning (A/C) compressor disengages in order from 1 to 8 with 8 being the most recent. There are about 8 possible causes for the A/C compressor to disengage.

A/C High Side Pressure

A/C OFF

1.24 Volts

This parameter displays the voltage from the A/C high side pressure sensor signal circuit to the control module.

A/C ON

1.45 Volts

A/C High Side Pressure

A/C OFF

500-2,200 kPa (72-319 psi)

This parameter displays the pressure from the A/C high side pressure sensor signal circuit to the control module.

A/C ON

300-1,200 kPa (43-174 psi)

A/C Off for WOT

A/C ON

No

This parameter displays whether the control module is commanding the A/C compressor clutch relay off for wide open throttle (WOT).

A/C Pressure Disable

A/C ON

No

This parameter displays whether the A/C pressure is out of range for normal operation as determined by the control module.

A/C Relay Ckt Short Gnd Test Status

A/C ON or OFF

OK/Not Run

This parameter displays the state of the air conditioning (A/C) clutch relay control circuit. It can display OK, Fault or Not Run. The parameter displays Fault if the A/C clutch relay control circuit is shorted to ground.

A/C Relay Ckt Open Test Status

A/C ON or OFF

OK/Not Run

This parameter displays the state of the air conditioning (A/C) clutch relay control circuit. It can display OK, Fault or Not Run. The parameter displays Fault if the A/C clutch relay control circuit is open.

A/C Relay Ckt Short Volts Test Status

A/C ON or OFF

OK/Not Run

This parameter displays the state of the air conditioning (A/C) clutch relay control circuit. It can display OK, Fault or Not Run. The parameter displays Fault if the A/C clutch relay control circuit is shorted to voltage.

A/C Relay Command

A/C ON

On

This parameter displays the state of the air conditioning (A/C) clutch relay control circuit as commanded by the control module.

A/C Request Signal

A/C ON

Yes

This parameter displays the state of the A/C request input to the control module from the heating, ventilation, and air conditioning (HVAC) controls.

Air Flow Calculated

--

g/s Varies

This parameter displays the air flow of the engine as calculated by the control module using information from the manifold absolute pressure (MAP) sensor. The scan tool will display a range of values indicating a high air flow when MAP pressure is high and a low air flow when MAP pressure is low. This value is listed in grams per second (g/s).

Ambient Air Temperature

--

°C °F Varies

This parameter displays the surrounding air temperature.

APP Indicated Angle

Accelerator pedal not actuated

0%

This parameter displays the angle of the accelerator pedal position (APP) as calculated by the control module using the signals from the APP sensors.

Accelerator pedal fully actuated

100%

APP Sensor 1

Accelerator pedal not actuated

0.7-1.2 Volts

This parameter displays the actual voltage on the accelerator pedal position (APP) sensor 1 signal circuit as measured by the control module.

Accelerator pedal fully actuated

4.2-4.5 Volts

APP Sensor 2

Accelerator pedal not actuated

0.3-0.5 Volts

This parameter displays the actual voltage on the accelerator pedal position (APP) sensor 2 signal circuit as measured by the control module.

Accelerator pedal fully actuated

2.2-2.5 Volts

APP Sensor 1 and 2

--

Agree

This parameter displays Disagree if the control module detects the signal voltage from APP sensor 1 is not in correct relationship to APP sensor 2. The scan tool displays Agree under the normal operating conditions.

Average Injector PWM

--

1 Ms

This parameter displays the average ON time of all the Injectors.

BARO

--

65-104 kPa (8-16 psi)

This parameter displays the barometric pressure. The control module uses the barometric pressure sensor input for fuel control to compensate for altitude differences.

BARO

--

2.5-4.0 Volts

This parameter displays the barometric pressure sensor voltage.

Brake Pedal Signal Status

--

Valid/Invalid

This parameter displays the serial data message of the brake signal from the electronic brake and traction control module (EBTCM).

Calculated ECT - Closed Loop Fuel Control

--

-39 to +40°C

(-38 to +104°F)

This parameter displays the modeled temperature that the control module calculates from air entering the engine, coolant temperature, and ambient air temperature. If the actual engine coolant temperature does not reach this calculated temperature within a predetermined amount of time, a DTC will set.

Calculated ECT - Thermostat Diagnosis

--

-39 to +140°C (-38 to +284°F)

This parameter displays the modeled temperature that the control module calculates from air entering the engine, coolant temperature, and ambient air temperature. If the actual engine coolant temperature does not reach this calculated temperature within a predetermined amount of time, a DTC will set.

Calc. TWC Temp. Bank 1 and 2

--

414°C (773°F)

This parameter displays the catalytic converter temperature as calculated by the control module.

Catalytic Converter Protection Active

--

No

This parameter displays if the control module is commanding catalytic converter protection.

Catalyst Monitor Complete This Ignition

--

Yes

This parameter displays the monitor completion status during the current driving/monitoring cycle.

Catalyst Monitor Enabled this Ignition

--

Yes

This parameter displays the monitor enable status during the current driving/monitoring cycle.

CKP Resync Counter

--

0 Counts

This parameter displays the number of times the control module re-syncs with the CKP sensor.

Clutch Start Switch, If Equipped

Clutch pedal not actuated

Off

This parameter displays the state of the clutch pedal as determined by the control module from the clutch start switch.

Clutch pedal fully actuated

On

Cold Startup

--

Yes/No

This parameter displays whether the engine meets the conditions for a cold startup during the present ignition cycle. The scan tool displays Yes when the conditions for a cold startup are met during this ignition cycle. The scan tool displays No when the conditions for a cold startup are not met during the present ignition cycle. Conditions for a cold startup require the coolant temperature and the intake air temperature to be below a predetermined temperature and within a certain range of each other. These conditions must occur after the engine was warmed up to a specific temperature during the previous ignition cycle.

Commanded A/F Equivalence Ratio

--

14.7:1

This parameter displays the ratio of air to fuel as calculated by the control module based on various sensor inputs. The scan tool will display a lower air fuel ratio when a richer air to fuel mixture is commanded. The scan tool will display a higher air fuel ratio when a leaner air to fuel mixture is commanded. In closed loop operation the air fuel ratio should normally be around 14.2-14.7 to 1.

Component Monitor Enable This Ignition

--

Yes

This parameter displays the diagnostic monitor enable status during the current driving/monitoring cycle.

Control Module Voltage

--

14.25 volts

This parameter displays the state of the ignition system voltage available at the control module.

CPP Switch, If Equipped

Clutch pedal not actuated

Released

This parameter displays the state of the clutch pedal as determined by the control module from the clutch pedal switch.

Clutch pedal fully actuated

Applied

Crank Request Signal

Ignition switch not in the crank position

No

This parameter displays whether the ignition switch has been cycled to the crank position requesting the control module to activate the starter relay.

Ignition switch in the crank position

Yes

Cruise Control Active

--

No

This parameter displays the status of the cruise control system as determined by the control module.

Cruise Disengage 1-8 History

Cruise ON

Reason for Cruise Disengagement

The parameter displays the last 8 cruise control disengages in order from 1 to 8, with 8 being the most recent. There are about 33 possible causes for the cruise control to disengage.

Cruise Inhibited

Cruise ON

No

The parameter displays the reason why the cruise control system is inhibited.

Cruise On/Off Switch

--

On/Off

The engine control module (ECM) monitors the signal circuit of the cruise control switch. A closed switch is displayed as On.

Cruise Resume/Accel. Switch

--

Active/Inactive

The scan tool displays On, when the cruise On/Off switch is ON and the resume/accel (+) button is pressed, the ECM detects a predetermined voltage value for the resume/accel. switch.

Cruise Set/Coast Switch

--

Active/Inactive

The scan tool displays On, when the cruise on/off switch is ON and the ECM detects a predetermined voltage value for the set/coast (-) switch.

Current Gear

Transmission in Park/Neutral

P/N

This parameter displays the transmission gear commanded by the transmission control module.

Transmission not in Park/Neutral

Reverse/1st-5th

Cycles of Misfire Data

--

0-200 counts

This parameter displays the number of misfire tests during 200 engine revolutions.

Cyl. 1-6 IC Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the Ignition control circuit. The parameter displays Fault if the Ignition control circuit is shorted to ground.

Cyl. 1-6 IC Ckt OpenTest Status

--

OK/Not Run

This parameter displays the state of the Ignition control circuit. The parameter displays Fault if the Ignition control circuit is open.

Cyl. 1-6 IC Ckt Short VoltsTest Status

--

OK/Not Run

This parameter displays the state of the Ignition control circuit. The parameter displays Fault if the Ignition control circuit is shorted to voltage.

Cyl. 1-6 Inj. Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the fuel injector control circuit. The parameter displays Fault if the fuel injector control circuit is shorted to ground.

Cyl. 1-6 Inj. Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the fuel injector control circuit. The parameter displays Fault if the fuel injector control circuit is open.

Cyl. 1-6 Inj. Ckt Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the fuel injector control circuit. The parameter displays Fault if the fuel injector control circuit is shorted to voltage.

Cylinder 1-6 Knock Retard

--

0 Degrees

This parameter displays the knock retard as commanded by the control module for cylinders 1-6. Each cylinder is controlled individually based on both knock sensor signal inputs.

Decel. Fuel Cutoff

--

Inactive

This parameter displays the status of the operating mode of the control module used to turn off the fuel injectors and the EVAP canister purge valve during certain deceleration conditions.

Desired Exh. CMP Bank 1 or 2

Engine Idling

0 Degrees

This parameter displays the desired exhaust camshaft angle as commanded by the control module.

Engine speed at 2000 RPM

10 Degrees

Desired HO2S Bank 1 or 2 Sensor 1

--

Varies 400-700 mV

This parameter displays the voltage output from the HO2S to the control module. A lower voltage indicates a lean exhaust, while a higher voltage indicates a rich exhaust.

Desired Idle Speed

--

Approximately 650 RPM

This parameter displays the desired engine idle speed as commanded by the control module.

Desired Int. CMP Bank 1 or 2

Engine Idling

0 Degrees

This parameter displays the desired intake camshaft angle as commanded by the control module.

Engine speed at 2000 RPM

10 Degrees

DTC Set This Ignition

--

No

This parameter displays Yes if a DTC set on the current ignition cycle.

EC Ignition Relay Command

--

On

This parameter displays the state of the control circuit for control module power relay as commanded by the control module.

EC Ignition Relay Circuit Test Status

--

OK/Fault/Not Run

This parameter displays the state of the EC Ignition Relay control circuit. The parameter displays Fault if the EC Ignition Relay control circuit is open, shorted to ground, or shorted to voltage.

EC Ignition Relay Feedback Signal

--

12.0-14.5 Volts

This parameter displays the voltage available at the EC ignition relay pin of the control module.

ECM Reset

--

No

This parameter displays Yes when an internal control module reset occurs. The scan tool displays NO under normal operating conditions.

ECM in VTD Fail Enable

--

No

This parameter indicates whether or not the engine control module (ECM) is in failure enable mode for the vehicle theft deterrent (VTD) system.

ECT Sensor

--

88 to 105°C (190 to 221°F)

This parameter displays the temperature of the engine coolant based on input to the control module from the engine coolant temperature (ECT) sensor.

Engine Load

Engine Idling

25-45%

This parameter displays the calculated engine load in percent based on inputs to the control module from various engine sensors.

Engine speed at 2,500 RPM

40-60%

Engine OFF EVAP Test Conditions Met

--

No

This parameter displays Yes if the conditions for running the Engine Off EVAP diagnostic are met.

Engine Off Time

Engine OFF

0:00:00 Seconds - Varies

This parameter displays the amount of time that has elapsed since the engine was last cycled OFF.

Engine Oil Level Switch

--

OK

This parameter displays if the level of the engine oil is within range as determined by the control module from information received from the engine oil level switch.

Engine Oil Life Remaining

--

0-100%

This parameter displays the percent of engine oil life remaining. The controller calculates the engine oil life by monitoring engine load, coolant temperature, and engine speed.

Engine Oil Pressure Sensor

--

103 kPa (15 psi) to 241 kPa (35 psi)

This parameter displays the engine oil pressure.

Engine Oil Temperature Sensor

--

97°C (204°F)

This parameter displays the engine oil temperature.

Engine Run Time

Engine Operating

0:00:00

Increments when the engine is operating

This parameter displays the time elapsed since the engine was started.

Engine Speed

Engine Cranking

Greater than 60 RPM

This parameter displays the speed of the engine crankshaft rotation from information received from the crankshaft position (CKP) sensor. If there is a CKP sensor DTC, the ECM calculates the engine speed from one of the camshaft position (CMP) sensors.

Engine Idling

550-700 RPM

EVAP Monitor Complete This Ignition

--

Yes/No

This parameter displays the diagnostic monitor completion status during the current driving/monitoring cycle.

EVAP Monitor Enabled This Ignition

--

Yes/No

This parameter displays the diagnostic monitor enable status during the current driving/monitoring cycle.

EVAP Purge Sol Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the evaporative emission (EVAP) purge solenoid control circuit. The parameter displays Fault if the EVAP purge solenoid control circuit is shorted to ground.

EVAP Purge Sol Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the evaporative emission (EVAP) purge solenoid control circuit. The parameter displays Fault if the EVAP purge solenoid control circuit is open.

EVAP Purge Sol Ckt Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the evaporative emission (EVAP) purge solenoid control circuit. The parameter displays Fault if the EVAP purge solenoid control circuit is shorted to voltage.

EVAP Purge Solenoid Command

--

0-100%

This parameter displays the on-time or duty cycle of the EVAP canister purge solenoid commanded by the control module. Zero percent indicates no purge. One hundred percent indicates full purge.

EVAP Vent Sol Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the EVAP vent solenoid control circuit. The parameter displays Fault if the EVAP vent solenoid control circuit is shorted to ground. This parameter may not change if the scan tool is used to command the EVAP vent solenoid ON.

EVAP Vent Sol Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the EVAP vent solenoid control circuit. The parameter displays Fault if the EVAP vent solenoid control circuit is open. This parameter may not change if the scan tool is used to command the EVAP vent solenoid ON.

EVAP Vent Sol Ckt Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the EVAP vent solenoid control circuit. The parameter displays Fault if the EVAP vent solenoid control circuit is shorted to voltage. This parameter may not change if the scan tool is used to command the EVAP vent solenoid ON.

EVAP Vent Solenoid Command

--

Venting

This parameter displays the state of the control circuit for evaporative emission (EVAP) vent solenoid as commanded by the control module.

Extended Traval Brake Pedal Switch

--

Released

This parameter will display the state of the brake pedal, applied or released.

Exh. CMP Angle Bank 1 or 2

Engine Idling

0 Degrees

This parameter displays the actual exhaust camshaft position in degrees.

Engine speed at 2000 RPM

10 Degrees

Exh. CMP Angle Bank 1 or 2 Variance

Engine Idling

0 Degrees

This parameter displays in degrees, the difference between the desired exhaust camshaft position and the actual exhaust camshaft position.

Engine speed at 2000 RPM

10 Degrees

Exh. CMP Bank 1 or 2 Command

Engine Idling

20%

This parameter displays the exhaust camshaft position in percent of range as commanded by the control module.

Engine speed at 2000 RPM

50%

Exh CMP Sol Bn 1 or 2 Ckt ShortGnd Test Status

--

OK/Not Run

This parameter displays the state of the exhaust camshaft actuator solenoid control circuit. The parameter displays Fault if the camshaft actuator solenoid control circuit is shorted to ground.

Exh CMP Sol Bn 1 or 2 Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the exhaust camshaft actuator solenoid control circuit. The parameter displays Fault if the camshaft actuator solenoid control circuit is open.

Exh CMP Sol Bn 1 Ckt or 2 Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the exhaust camshaft actuator solenoid control circuit. The parameter displays Fault if the camshaft actuator solenoid control circuit is shorted to voltage.

FC Relay 1 Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the fan relay control circuit. The parameter displays Fault if the fan relay control circuit is shorted to ground.

FC Relay 1 Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the fan relay control circuit. The parameter displays Fault if the fan relay control circuit is open.

FC Relay 1 Ckt Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the fan relay control circuit. The parameter displays Fault if the fan relay control circuit is shorted to voltage.

FC Relays 2 and 3 Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the fan relay control circuit. The parameter displays Fault if the fan relay control circuit is shorted to ground.

FC Relays 2 and 3 Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the fan relay control circuit. The parameter displays Fault if the fan relay control circuit is open.

FC Relays 2 and 3 Ckt Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the fan relay control circuit. The parameter displays Fault if the fan relay control circuit is shorted to voltage.

FC Relay 1 Command

Engine coolant less than 108°C (226°F)

A/C Off

Off

This parameter displays the control module commanded state of the fan relay control circuit.

Engine coolant greater than 108°C (226°F)

A/C On

On

FC Relay 2 and 3 Command

Engine coolant less than 108°C (226°F)

A/C OFF

Off

This parameter displays the control module commanded state of the fan relay control circuit.

Engine coolant greater than 108°C (226°F)

A/C ON

On

Fuel Level

--

0-100%

This parameter displays the amount of fuel in the fuel tank in percent of range, as calculated by the control module.

Fuel Level Sensor Left Tank (Secondary) and Fuel Level Sensor Right Tank (Primary)

--

0-5 Volts

This parameter displays the voltage signal received by the control module from the fuel level sensors.

Fuel Pump Relay Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the fuel pump relay control circuit. The parameter displays Fault if the fuel pump relay control circuit is shorted to ground.

Fuel Pump Relay Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the fuel pump relay control circuit. The parameter displays Fault if the fuel pump relay control circuit is open.

Fuel Pump Relay Ckt Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the fuel pump relay control circuit. The parameter displays Fault if the fuel pump relay control circuit is shorted to voltage.

Fuel Pump Relay Command

Ignition ON, engine OFF

Fuel pump on for 2 seconds

This parameter displays the control modules commanded state of the fuel pump relay control circuit.

Engine idling

On

Fuel Tank Level Remaining

--

Liter/Gallon - Varies

This parameter displays the amount of fuel in liters/gallons that remains in the fuel tank as determined by the control module from information received from the left and right fuel level sensors.

Fuel Tank Pressure Sensor

Ignition ON, engine OFF

0 in H2O/mm Hg

This parameter displays the pressure/vacuum inside the fuel tank. A negative value indicates a vacuum, while a positive value indicates a pressure.

Fuel Tank Pressure Sensor

Ignition ON, engine OFF

0-5 Volts

This parameter displays the voltage signal received by the control module from the fuel tank pressure (FTP) sensor.

Fuel Tank Rated Capacity

--

17.8 Gallons (67.3 Liters)

This parameter displays the capacity of the fuel tank in liters or gallons.

Fuel Trim Learn

--

Enabled

This parameter displays Enabled when conditions are appropriate for enabling long term fuel trim corrections. This indicates that the long term fuel trim is adapting continuing amounts of short term fuel trim. If the scan tool displays Disabled, then long term fuel trim will not respond to changes in short term fuel trim.

GEN L-Terminal Signal Command

--

0-100%

This parameter displays the control modules commanded state of the voltage regulator on the generator.

Generator F-Terminal Signal

--

0-100%

This parameter displays the amount of generator on-time as commanded by the control module. The higher the percentage the greater the generator output.

HO2S Bank 1 or 2 Sensor 1

--

400-700 mV - Varies

This parameter displays the voltage output from the HO2S to the control module. A lower voltage indicates a lean exhaust, while a higher voltage indicates a rich exhaust.

HO2S Bank 1 or 2 Sensor 2

--

400-700 mV - Varies

This parameter displays the voltage output from the HO2S to the control module. A lower voltage indicates a lean exhaust, while a higher voltage indicates a rich exhaust.

HO2S Heater Monitor Complete This Ignition

--

Yes

This parameter displays the diagnostic monitor completion status during the current driving/monitoring cycle.

HO2S Heater Monitor Enabled This Ignition

--

Yes

This parameter displays the diagnostic monitor enable status during the current driving/monitoring cycle.

HO2S Bank 1 Sensor 2 Heater Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the oxygen sensor heater control circuit. The parameter displays Fault if the oxygen sensor heater control circuit is shorted to ground.

HO2S Bank 1 Sensor 2 Heater Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the oxygen sensor heater control circuit. The parameter displays Fault if the oxygen sensor heater control circuit is open.

HO2S Bank 1 Sensor 2 Heater Ckt Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the oxygen sensor heater control circuit. The parameter displays Fault if the oxygen sensor heater control circuit is shorted to voltage.

HO2S Htr. Bn. 1 or 2 Sensor 1 Command

--

0-99%

This parameter displays the commanded state of the heater control circuit as commanded by the control module.

HO2S/O2S Monitor Complete This Ignition

--

Yes

This parameter displays the diagnostic monitor completion status during the current driving/monitoring cycle.

HO2S/O2S Monitor Enabled This Ignition

--

Yes

This parameter displays the diagnostic monitor enable status during the current driving/monitoring cycle.

HO2S Sensing Element Bn. 1 or 2 Sensor 1

--

70-90 Ohms

Depends on Temperature

This parameter displays the resistance of the sensing element within the control module.

HO2S Sensing Element Bn. 1 or 2 Sensor 2

--

20-300 Ohms

Depends on Temperature

This parameter displays the resistance of the sensing element within the control module.

HO2S Bn. 1 or 2 Sensor 1 Module Signal

--

1-5 Volts

This parameter displays the voltage of the HO2S control transistor, which is internal to the ECM.

IAT Sensor

--

-39° to +140°C

(-38° to +284°F)

This parameter displays the temperature of the air entering the air induction system based on input to the control module from the intake air temperature (IAT) sensor.

Ignition 0 Signal

--

On

This parameter displays On when the control module detects a voltage at the ignition 0 input terminal.

Ignition 1 Signal

--

B+

This parameter displays B+ when the control module detects a voltage at the ignition 1 input terminal.

Ignition 1 Signal

--

On

This parameter displays On when the control module detects a voltage at the ignition 1 input terminal.

IMRC Solenoid Circuit Status, If Equipped

--

OK/Fault/Not Run

This parameter displays the state of the intake manifold runner control (IMRC) control circuit. The parameter displays Fault if the IMRC control circuit is open, shorted to ground, or shorted to voltage.

IMRC Solenoid Command, If Equipped

--

Off

This parameter displays the control modules commanded state of the IMRC solenoid.

Initial Brake Apply Signal

Brake pedal not actuated

Released

This parameter displays the state of the brake pedal that is transmitted over the serial data circuit from the electronic brake control module (EBCM).

Brake pedal fully actuated

Applied

Injector 1-6 Command

Engine idling

0.82-1.20 ms

This parameter displays the amount of fuel injector ON time or pulse width as commanded by the control module.

Int. CMP Angle Bank 1 or 2

Engine Idling

0 Degrees

This parameter displays the actual intake camshaft position in degrees.

Engine speed at 2000 RPM

10 Degrees

Int. CMP Angle Bank 1 or 2 Variance

Engine Idling

0 Degrees

This parameter displays in degrees, the difference between the desired intake camshaft position and the actual exhaust camshaft position.

Engine speed at 2000 RPM

0 Degrees

Int. CMP Bank 1 or 2 Command

Engine Idling

0 Degrees

This parameter displays the intake camshaft position in percent of range as commanded by the control module.

Engine speed at 2000 RPM

50 Degrees

Int CMP Sol Bn 1 or 2 Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the intake camshaft actuator solenoid control circuit. The parameter displays Fault if the camshaft actuator solenoid control circuit is shorted to ground.

Int CMP Sol Bn 1 or 2 Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the intake camshaft actuator solenoid control circuit. The parameter displays Fault if the camshaft actuator solenoid control circuit is open.

Int CMP Sol Bn 1 or 2 Ckt Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the intake camshaft actuator solenoid control circuit. The parameter displays Fault if the camshaft actuator solenoid control circuit is shorted to voltage.

Knock Retard

--

0 Degrees

This parameter indicates the amount of spark advance the control module removes from the ignition control (IC) spark advance in response to the signal from the knock sensors.

KS 1 or 2 Signal

--

3.86-5.02 Volts

This parameter displays the voltage input to the control module from the knock sensor (KS).

Loop Status Bn 1 or 2 Sen. 1

--

Closed Loop

This parameter displays the state of the fuel control system as commanded by the control module. Closed Loop operation indicates that the control module is controlling the fuel delivery based off the oxygen sensors input signal. In Open Loop operation the control module ignores the oxygen sensor input signal and bases the amount of fuel to be delivered on other sensor inputs.

Loop Status Bn 1 or 2 Sen. 2

--

Open Loop

This parameter displays the state of the rear heated oxygen sensors as commanded by the control module. The rear sensors will not go into Closed Loop until the ECM determines that the HO2S is ready for operation.

Low EOP Indicator Command

--

Off

This parameter displays the commanded state of the low EOP lamp control circuit by the control module.

LT FT Bn. 1 or Bn.

--

0%

This parameter displays the commanded Long Term Fuel Trim correction by the control module for bank 1 or bank 2 for cruise and acceleration conditions.

LT FT Bn. 1 or Bn. 2 Idle/Decel.

--

0%

This parameter displays the commanded Long Term Fuel Trim correction by the control module for bank 1 or bank 2 for idle and deceleration conditions.

MAF Sensor

Engine Idling

3.4-6.3 g/s

This parameter displays the measured quantity of air flowing into the engine during all operating conditions.

Engine speed at 2,500 RPM

11.88 g/s

MIL Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the MIL control circuit. The parameter displays Fault if the MIL control circuit is shorted to ground.

MIL Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the MIL control circuit. The parameter displays Fault if the MIL control circuit is open.

MIL Ckt Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the MIL control circuit. The parameter displays Fault if the MIL control circuit is shorted to voltage.

MIL Command

--

Off

This parameter displays the commanded state of the malfunction indicator lamp (MIL) control circuit by the control module.

Mil Requested by DTC

--

No

This parameter indicates the reason the control module illuminated the MIL. The scan tool will display YES when the MIL is requested as a result of an A or B type DTC. The scan tool will display NO if the MIL is illuminated for another reason, such as transmission DTCs.

Mileage Since DTC Cleared

--

km - miles

This parameter displays the mileage that has elapsed since any diagnostic trouble code (DTC) has been cleared from the control modules memory.

Mileage Since DTC First Failure

--

km - miles

This parameter displays the mileage that has elapsed since the first emission failure.

Mileage Since DTC Last Failure

--

km - miles

This parameter displays the mileage that has elapsed since the last emission failure.

Mileage Since MIL Requested

--

km - miles

This parameter displays the mileage that has elapsed since the control module has commanded the malfunction indicator lamp (MIL) On.

Misfire Current Cyl. 1-6

--

0

The scan tool displays a range of 0-200 counts. This parameter displays the number of misfires that have been detected during the last 200 cylinder firing events. The counters may normally display some activity, but the activity should be nearly equal for all of the cylinders, and in low numbers.

Misfire History Cyl. 1-6

--

0

The scan tool displays a range of 0-65,535 counts. The misfire history counters display the total level of misfire that has been detected on each cylinder. The misfire history counters will not update or show any activity until a misfire DTC P0300 has become active. The misfire history counters will update every 200 cylinder firing events.

Moderate Brake Apply Signal

Brake pedal not actuated

Released

This parameter displays the state of the brake pedal that is transmitted over the serial data circuit from the electronic brake control module (EBCM).

Brake pedal fully actuated

Applied

PNP Switch

Transmission in Park/Neutral

Park/Neutral

This parameter displays whether the transmission range selector is in park or neutral.

Transmission not in Park/Neutral

In Gear

Power Enrichment

--

Inactive

This parameter displays the status of the operating mode of the control module used to increase fuel delivery during certain acceleration conditions.

Reduced Engine Power

--

Inactive

This parameter displays whether the control module is commanding reduced engine power due to a throttle actuator control (TAC) system condition.

RVS Disable 1-8 History

--

Reason for RVS Disable

This parameter displays one of the last eight reasons that powertrain has disabled remote vehicle start (RVS).

Short Term FT Bank 1 or Bank 2

--

-3% to +3%

This parameter displays the short-term correction to the fuel delivery by the control module in response to oxygen sensor 1 or 2. If the oxygen sensor indicates a lean air/fuel mixture, the control module will add fuel increasing the short term fuel trim above 0. If the oxygen sensor indicates a rich air/fuel mixture, the control module will reduce fuel decreasing the short term fuel trim below 0.

Spark

--

2-10 Degrees

This parameter displays the amount of spark advance the control module is commanding on the ignition control circuits. The control module determines the desired advance.

Starter Relay Ckt Short Gnd Test Status

--

OK/Not Run

This parameter displays the state of the starter relay control circuit. The parameter displays Fault if the starter relay control circuit is shorted to ground.

This parameter may not change if the scan tool is used to command the relay control circuit ON.

Starter Relay Ckt Open Test Status

--

OK/Not Run

This parameter displays the state of the starter relay control circuit. The parameter displays Fault if the starter relay control circuit is open.

This parameter may not change if the scan tool is used to command the relay control circuit ON.

Starter Relay Ckt Short Volts Test Status

--

OK/Not Run

This parameter displays the state of the starter relay control circuit. The parameter displays Fault if the starter relay control circuit is shorted to voltage.

This parameter may not change if the scan tool is used to command the relay control circuit ON.

Starter Relay Command

Ignition switch not in the crank position

Off

This parameter indicates whether the control module is commanding the starter relay to go on or off.

Ignition switch in the crank position

On

Start Up ECT

--

-39° to +140°C (-38° to +284°F)

This parameter displays the temperature of the engine coolant on start up based on input to the control module from the ECT sensor.

Start Up IAT

--

-39° to +140°C (-38° to +284°F)

This parameter displays the temperature of the intake air at start in the air induction system based on input to the control module from the IAT sensor.

Stoplamp Pedal Switch

Brake pedal not actuated

Released

This parameter displays the position of the stop lamp pedal switch input to the control module.

Brake pedal fully actuated

Applied

System Power Mode

--

Run

This parameter displays the position of the ignition switch.

TAC System Learned Counts

--

0

This parameter displays the steps counted in learning the throttle actuator control parameters. The last step learned is 11.

TCC Status

--

Unlocked

This parameter displays the commanded status of the torque convertor clutch.

TCM Requested Torque

--

N·m/lb ft

This parameter displays the calculated amount torque requested of the controller.

TCM Torque Increase

--

No

This parameter displays whether or not the controller has responded to a request for a torque increase.

TCS Torque Increase

--

No

This parameter displays whether or not the controller has responded to a request for a torque increase.

TCS Torque Reduction Active

--

No

This parameter displays whether the transmission control module (TCM) is reducing torque.

TCM Torque Reduction Active

--

No

This parameter displays whether EBTCM has determined a reduction in torque took place.

Torque Delivered Signal

--

0-100%

This is the calculated torque output from the engine to the transmission used by the EBTCM for the traction control system operation.

Torque Request Signal

--

0-100%

The EBTCM sends a Desired Torque Level signal request to the control module. This decreases torque from the powertrain in order to reduce wheel slip during acceleration for the traction control.

Total Fuel Trim Avg. Bank 1 or Bank 2

--

-100 to +100%

This parameter displays the overall fuel trim from the Long Term idle/decel parameter and the Long Term Fuel Trim cell.

Total Misfire Count

--

0

This parameter displays the total number of cylinder firing events that the control module detected as misfires for the last 200 crankshaft revolution sample period.

TP Desired Angle

--

0-100%

This parameter displays the desired TP angle commanded by the control module.

TP Indicated Angle

--

0-100%

This parameter displays the percent of throttle opening as calculated by the control module using information from the two TP sensors.

TP Sensor 1

--

0.5-0.8 Volts

This parameter displays the actual voltage on the TP sensor 1 signal circuit as measured by the control module.

TP Sensor 1 Learned Minimum

--

0-0.6 Volts

This parameter displays the learned minimum value of throttle position (TP) sensor 1 as recorded by the control module during the last learn procedure.

TP Sensor 2

--

4.7-4.1 Volts

This parameter displays the actual voltage on the TP sensor 2 signal circuit as measured by the control module.

TP Sensor 2 Learned Minimum

--

5.0-3.7 Volts

This parameter displays the learned minimum value of TP sensor 2 as recorded by the control module during the last learn procedure.

TP Sensors 1 and 2

--

Agree

This parameter displays Disagree when the control module detects that TP sensor 1 voltage signal is not within the correct relationship to TP sensor 2. The scan tool displays Agree under the normal operating conditions.

Traction Control Status

--

Inactive

This parameter displays Active if the electronic brake and traction control module (EBTCM) is commanding traction control.

Vehicle Security Status

--

Fuel Continued

This parameter displays the status of the vehicle theft deterrent system.

Vehicle Speed Sensor

--

Km/h

mph

This parameter displays the speed of the vehicle as calculated by the transmission control module (TCM) from information received from the vehicle speed sensor (VSS).

Volumetric Efficiency

Engine Idling

5-25%

This parameter displays the calculated volumetric efficiency of the engine as calculated by the control module.

Engine speed at 2,500 RPM

5-25%

VTD Auto. Learn Timer

--

Inactive

This parameter indicates that either the auto learn timer (used in the auto learn procedure to enable VTD password learning) or the seed and key timer (used in the seed and key procedure to enable VTD password learning) is active.

VTD Fuel Disable

--

Inactive

This parameter indicates the VTD system has disabled fuel.

VTD Fuel Disable Until Ign. Off

--

No

This parameter indicates the VTD system has disabled fuel for the remainder of the ignition cycle.

VTD Password learned

--

Yes

This parameter indicates learning of the VTD password received from the platform electronics is enabled. VTD password learning is first enabled in assembly plant (prior to the manufacturer’s enable counter being set to zero) may be re-enabled using 1 of 2 procedures.

Warm Ups Since DTC Cleared

--

Counts

This parameter indicates the number of warm up cycles that have occurred Since DTCs were cleared. The scan tool will display a higher counts as more warm up cycles have occurred since the DTCs were cleared.

Engine Control Module (ECM) Scan Tool Output Controls

Output Control

Description

A/C Relay

The engine must be running and the ECM must receive an A/C request from the HVAC control module in order to enable the output control. The ECM de-energizes the A/C compressor clutch relay when you select OFF. The relay remains de-energized until you select ON.

CMP Actuator Intake/Exhaust Bank 1 or Bank 2

This function controls the selected camshaft actuator solenoid. The normal commanded state is NONE. The system will increase or decrease the angle of the selected camshaft in 5 degree increments up to 40 crankshaft degrees. The scan tool initiates the test when the following conditions are met:

    • The vehicle speed is 0 km/h (0 mph).
    • The transmission is in park or neutral.
    • The engine speed is between 1,000-1,400 RPM.

The system remains in the commanded state until cancelled by the scan tool.

CMP Sol. Intake/Exhaust Bank 1 or Bank 2

This function controls the selected camshaft actuator solenoid. The normal commanded state is NONE. When commanded ON/OFF, the ECM turns the camshaft actuator solenoid ON/OFF. The scan tool initiates the test when the following conditions are met:

    • The ignition is ON with the engine OFF.
    • No engine speed is detected.

The system remains in the commanded state until cancelled by the scan tool.

Cooling Fan Relay 1

Activates the cooling fan relay 1. The normal commanded state of the fan relay is NONE. The relay command status can also be monitored on the scan tool data parameter FC Relay 1 Command. The PCM allows cooling fan relay control when the following conditions are met:

    •  The ignition is ON or the engine is running.
    • A/C compressor operation is not requested.
    •  The engine coolant temperature is less than 106°C (224°F).

Cooling Fan Relay 2 & 3

Activates the cooling fan relay 2 and relay 3. The normal commanded state of the fan relays is NONE. The relay command status can also be monitored on the scan tool data parameter FC Relay 2 and 3 Command. The PCM allows cooling fan relay control when the following conditions are met:

    • The ignition is ON or the engine is running.
    •  A/C compressor operation is not requested.
    • The engine coolant temperature is less than 106°C (224°F).

Cylinder Power Balance

Important: The Misfire Current and Misfire History parameters may not increment when using this function.

This function disables the selected fuel injector. The normal commanded state is None. The scan tool initiates the test when the following conditions are met:

    • The engine is operating and the engine idle is stable.
    • The vehicle speed is 0 km/h (0 mph).
    • There are no DTCs set for the vehicle speed sensor.

If the fuel injector was disabled for 30 seconds, fuel injector control is not allowed again on the same fuel injector for 60 seconds.

Engine Speed Control

This function controls the idle speed override in 25 RPM, 100 RPM, and 500 RPM increments, from the base idle speed to 1,400 RPM. The scan tool initiates the test when the following conditions are met:

    • The transmission is in park or neutral.
    • The engine speed is less than 1,000 RPM.

The engine speed will remain in the commanded state until cancelled by the scan tool.

EVAP Purge Solenoid

Important: The EVAP Purge Solenoid Command parameter may not change states when using this output control.

This function controls the evaporative emission (EVAP) purge solenoid valve. The normal commanded state is NONE. The system will increase or decrease the amount of purge by changing the duty cycle of the purge valve in 10 percent increments within a range of 0-100 percent. The system remains in the commanded state until cancelled by the scan tool or the fuel tank pressure (FTP) sensor exceeds -24 mm Hg (-12 inch H20).

EVAP Purge/Seal

Important: The EVAP Purge and Vent Solenoid Command parameters may not change states when using this output control.

This function activates both the EVAP purge solenoid valve and EVAP vent solenoid to seal the EVAP system. When activated, the purge valve is commanded to 0 percent and the vent valve is commanded ON, Not-venting. The normal commanded state for both solenoids is None. Both of the solenoids remain in the commanded state until cancelled by the scan tool or the FTP sensor exceeds -24 mm Hg (-12 inch H20).

EVAP Vent Solenoid

Important: The EVAP Vent Solenoid Command parameter may not change states when using this output control.

This function controls the EVAP vent solenoid. The normal commanded state is NONE. When commanded ON, the vent valve switches to Not-venting. The system remains in the commanded state unless one of the following conditions occur:

    • Cancelled by the scan tool
    • The EVAP canister purge solenoid is more than 0 percent, and the FTP sensor exceeds -24 mm Hg (-12 inch H20).

Fuel Injector Balance Test

This function enables the fuel injector in order to verify the correct fuel injector flow. The ECM will pulse the selected fuel injector when the following conditions are met:

    • All instruction on the scan tool is complete.
    • A fuel injector is selected.
    • The ignition is ON with the engine OFF.

The selected fuel injector can only be flowed/pulsed once per ignition cycle.

Fuel Pump Relay

This function controls the fuel pump relay. The normal commanded state is NONE. The scan tool initiates the test when the following conditions are met:

    • There are no vehicle speed sensor DTCs set.
    • The vehicle speed is 0 km/h (0 mph).

When commanded ON/OFF, the engine control module (ECM) turns the fuel pump relay ON/OFF. If the engine is running and the fuel pump relay is commanded OFF, the engine will stall. The system remains in the commanded state for about 2 seconds or until cancelled by the scan tool or the ECM detects a vehicle speed.

Fuel Trim Reset

This function resets the fuel trim data and the learned values for the rear heated oxygen sensors.

Generator L-Terminal

Commands the generator L terminal On and Off.

HO2S Htr. Bn. 1 or 2 Sen. 1 or 2 Command

Commands HO2S heater ON, 0-100 percent in 10 percent increments while the engine is running.

Idle Learn Reset

This function allows the throttle position and the idle speed to be relearned by the ECM, once the following conditions have been met.

    • The ignition is ON with the engine OFF.
    • The ECT is between 5-85°C (41-185°F).
    • No throttle actuator control (TAC) system DTCs are set.

Idle Spark

Disables and enables idle spark advance with the engine running.

IMRC Solenoid, If Equipped

This function controls the intake manifold runner control (IMRC) solenoid. The normal commanded state is NONE. When commanded ON/OFF, the ECM turns the IMRC solenoid ON/OFF. The scan tool initiates the test when the following conditions are met:

    • There are no vehicle speed sensor DTCs set.
    • The vehicle speed is 0 km/h (0 mph).

The system remains in the commanded state until cancelled by the scan tool.

Loop Status

This function controls the heated oxygen sensor (HO2S) loop status. The commanded states include NONE, OPEN, and CLOSED. The normal commanded state is NONE. The loop status changes as commanded, OPEN or CLOSED.

The system remains in the commanded state until cancelled by the scan tool.

Malfunction Indicator Lamp

This function controls the malfunction indicator lamp (MIL). The normal commanded state is NONE. When commanded ON/OFF, the ECM turns the MIL ON/OFF. The system remains in the commanded state until cancelled by the scan tool.

Oil Life Reset

This output control is used to reset the engine oil life monitor from 0 to 100%.

Spark Retard

Controls the amount of spark retard. The scan tool will command an increase or decrease in the amount of spark retard in 1 degree increments, within a range of 1-10 degrees. The degrees of spark retard will remain in the commanded state until cancelled by the scan tool. The normal commanded states is NONE.

Starter Relay

Commands the starter relay ON and OFF.

Throttle Blade Control

This function controls the throttle valve in 10 percent increments. The scan tool initiates the test when the following conditions are met:

    • There are no vehicle speed sensor DTCs set.
    • The vehicle speed is 0 km/h (0 mph).
    • The ignition is ON, with the engine OFF.
    • The ECM is not commanding a throttle learn.

The system remains in the commanded state until cancelled by the scan tool.