GM Service Manual Online
For 1990-2009 cars only

The Engine Scan Tool Data List contains all of the engine related parameters that are available on the scan tool. The list is arranged in alphabetical order.

Use the Engine Scan Tool Data List only after verifying the following:

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

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 problem should be reported to the manufacturer. The 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. If all values are within the typical range described below, refer to Symptoms - Engine Controls for diagnosis.

The column labeled Data List indicates where a parameter is located on the scan tool. Review the scan tool operating manual for the exact locations of each term listed. The following is a description of each item listed:

All: The parameter is in all data lists indicated below.

ENG: General Engine Data

EE: Evaporative Emissions (EVAP) Data

MF: Misfire

CMP: Camshaft Phaser (CMP) System Data

TAC: Throttle Actuator Control (TAC) System Data

CC: Cruise Control Data

Scan Tool Parameter

Data List

Units Displayed

Typical Data Value

Engine Idling/Upper Radiator Hose Hot/Closed Throttle/Transmission in Park or Neutral/Closed Loop

APP Sensor 1

TAC, CC

Volts

0.75-0.80 Volts

APP Sensor 2

TAC, CC

Volts

1.60-1.65 Volts

AC Clutch

ENG, TAC, CC

On/Off

Off

AC Request Signal

ENG, TAC, CC

Yes/No

No

Cam Phase Angle Actual

CMP

Degrees

Cam Phase Angle Desired

CMP

Degrees

Cam Phase Angle Variance

CMP

Degrees

Camshaft Phase Solenoid DC

CMP

Percent

35-45%

Camshaft Phase Solenoid Command

ENG, MF

Active/Inactive

Active

Cruise Control

CC

Yes/No

No

Cruise Control Brake Switch

CC

Applied/Released

Applied

Cruise Control Resume/Accel Switch

CC

On/Off

Off

Cruise Control Set Spd

CC

km/h / mph

0 km/h

Cruise Control Set/Coast Switch

CC

On/Off

Off

Cruise Control Switch

CC

On/Off

Off

Decel Fuel Cutoff

ENG, MF

Active/Inactive

Inactive

Diagnostic Mode

ENG

Normal/Check

Normal

ECT Sensor

All

°C (°F)

80-90°C (176-194°F)

Engine Load

ENG, TAC, CC

Percent

11-20%

Engine Speed

All

RPM

650-750 RPM

Engine Speed at Misfire

MF

RPM

0 RPM

EVAP Purge Solenoid

EE

On/Off

Off

EVAP Vacuum Leak Pump

EE

On/Off

Off

EVAP Vent Solenoid Command

EE

Venting/Not Venting

Venting

Fuel Pump Relay Command

ENG, TAC, CC

On/Off

On

Fuel Tank Pressure Sensor-FWD

ENG, EE

Volts

Varies

Fuel Tank Pressure Sensor-AWD

ENG, EE

mm Hg/in H2O

Varies

High Electrical Load

ENG, MF

Yes/No

No

HO2S 1 - AWD

ENG, MF

mV

Varies

HO2S 1 - FWD

ENG, MF

Volts

Varies

HO2S 2

ENG, MF

mV

Varies

IAC Motor Command

ENG

Percent

27-47%

IAT Sensor

ENG, MF, TAC, CC

°C (°F)

Varies with underhood and ambient air temperatures

Ign. Cycle Counter

ENG, MF

Counts

0-400 Counts

Injector 1 Command

ENG, MF

ms

1.10-2.20 ms

Load at Misfire

MF

G/Rev

0.00 G/Rev

Long Term FT

ENG

Percent

-20% to +20%

Loop Status

All

Open/Closed

Closed

MAF Sensor

ENG, MF, TAC, CC

g/s

1.50-5.00 g/s

MIL Command

ENG, MF,TAC, CC

On/Off

Off

Misfire Current Cyl #1

MF

Counts

0

Misfire Current Cyl #2

MF

Counts

0

Misfire Current Cyl #3

MF

Counts

0

Misfire Current Cyl #4

MF

Counts

0

Number of DTC(s)

ENG, MF

Varies

0

PNP Switch*

ENG, TAC, CC

Park/Neutral or In Gear

Park/Neutral

Power Steering Switch

ENG

Normal/High Pressure

Normal, with steering straight ahead

Short Term FT

ENG

Percent

-20% to +20%

Spark

ENG, MF

Degrees

8-14°

Starter Switch

ENG

Released/Cranking

Released

TAC Motor

TAC, CC

Enabled/Disabled

Enabled

TAC Motor Closed Command

TAC, CC

Percent

4-14%

TAC Motor Current

TAC, CC

amps

3.00-3.01 amps

TAC Motor Open Command

TAC, CC

Percent

0%

Throttle Plate at Idle

TAC, CC

Yes/No

Yes

TCC Brake Pedal Switch*

ENG, TAC, CC

Released/Applied

Released

TCC Enable Solenoid Command*

ENG, TAC, CC

On/Off

Off

Total Fuel Trim Average

ENG

Counts

0.25-0.75 (varies)

Total Misfire Current Count

MF

Counts

0

TP Sensor

All

Percent

8-13%

TP Sensor 2

TAC, CC

Volts

2.30-2.40 Volts

Vehicle Speed Sensor

All

km/h/mph

0 km/h

*4-spd Automatic Transmission Equipped Vehicles Only