| Table 1: | Powertrain Control Module Scan Tool Data |
| Table 2: | Powertrain Control Module (PCM) Scan Tool Output Controls |
The Powertrain Control Module Scan Tool Data List contains all engine related parameters that are available on the scan tool. The Scan Tool Data List is a master list arranged in alphabetical order.
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.
Parameter | System State | Expected Value | Description |
|---|---|---|---|
Base Operating Conditions: Engine Idling/Radiator Hose Hot/Park or Neutral/Closed Loop | |||
APP Sensor 1 | Accelerator pedal not actuated | 0.75-0.80 Volts | This parameter displays the actual voltage of each APP sensor signal circuit as measured by the control module. |
Accelerator pedal fully actuated | 3.60-3.75 Volts | ||
APP Sensor 1 | Accelerator pedal not actuated | 13-15% | This parameter displays the angle of the APP as calculated by the control module using the signals from the APP sensors. |
Accelerator pedal fully actuated | 70-74% | ||
APP Sensor 2 | Accelerator pedal not actuated | 1.60-1.65 Volts | This parameter displays the actual voltage of each APP sensor signal circuit as measured by the control module. |
Accelerator pedal fully actuated | 4.40-4.55 Volts | ||
APP Sensor 2 | Accelerator pedal not actuated | 28-31% | This parameter displays the angle of the APP as calculated by the control module using the signals from the APP sensors. |
Accelerator pedal fully actuated | 85-89% | ||
AC Relay Command | A/C ON | On | This parameter indicates On whenever the powertrain control module (PCM) energizes the A/C compressor clutch relay. |
AC Request Signal | A/C ON | Yes | This parameter indicates whether the A/C switch on the instrument panel (IP) has been selected. |
Brake Pedal Switch | -- | Released | Indicates the status of the stop lamp circuit switch |
Cam Phase Angle Actual | -- | 0 Degrees | This parameter indicates the actual camshaft advance in relative degrees. The displayed value is calculated from CMP sensor and CKP sensor inputs. Normal Cam Phase Angle readings are 0 to 40 degrees, where each single degree displayed is approximately equal to 5 degrees of actual camshaft advance. |
Cam Phase Angle Desired | -- | 0 Degrees | This parameter indicates the desired intake camshaft advance in relative degrees. The PCM determines the desired advance in camshaft timing. On a normal engine this reading will be the same as the Cam Phase Angle. |
Cam Phase Angle Variance | -- | 0 Degrees | This parameter indicates the difference between the Cam Phase Angle and the Cam Phase Angle Desired. This value can be displayed in positive or negative degrees. |
Camshaft Phase Solenoid DC | -- | 35-45% | The scan tool range is 0-100 percent. This parameter displays the duty cycle (DC) of the intake CMP actuator solenoid valve. A reading of less than 20 percent indicates the PCM is retarding camshaft timing. A reading of 20 to 40 percent indicates the PCM is holding the camshaft timing at the current setting. A reading of more than 40 percent indicates the PCM is advancing camshaft timing. |
Camshaft Phase Solenoid Command | -- | Active | This parameter indicates whether the powertrain control module (PCM) is controlling the intake camshaft position (CMP) actuator solenoid valve. The scan tool will display Active when the PCM is commanding the intake CMP actuator solenoid. A CMP actuator solenoid that is in an Active mode is not necessarily advancing the camshaft phase. Only about 50 percent of the CMP actuator solenoid movement results in advancement of the camshaft phase. |
Cruise Control Active | Cruise Control ON | Yes | This parameter indicates whether vehicle speed is controlled by the cruise control system. |
Cruise Control Brake Switch | -- | Released | This parameter indicates the state of the cruise brake switch that is controlled by the position of the brake pedal. |
Cruise Control Resume/Accel Switch | Cruise Control Resume/Accel Switch ON | On | This parameter displays the state of the cruise controls resume/accel switch input to the control module. |
Cruise Control Set Spd | Cruise Control ON | Varies Km/h Varies mph | This parameter displays the driver requested vehicle speed that the cruise control system is to maintain. |
Cruise Control Set/Coast Switch | Cruise Control Set/Coast ON | On | This parameter displays the state of the cruise controls set/coast switch input to the control module. |
Cruise Control Switch | Cruise Control ON | On | This parameter displays the status of the cruise control switch. |
Decel. Fuel Cutoff | -- | Inactive | This parameter displays the status of the operating mode of the control module used to turn off the fuel injectors during certain deceleration conditions. |
Diagnostic Mode | -- | Normal | Indicates whether the vehicle diagnostics are operating in Normal mode or in Check mode. |
ECM/Immobilizer Status | -- | Serial Comm. | Indicates the status of communications between the engine/powertrain control module and the immobilizer module. |
ECT Sensor | -- | 80-90°C (176-194°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 | -- | 11-20% | This parameter displays the calculated engine load in percent based on inputs to the control module from various engine sensors. |
Engine Run Time | Engine Operating | 00:00:00 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 PCM calculates the engine speed from one of the camshaft position (CMP) sensors. |
Engine Idling | Approximately 650-750 RPM | ||
Engine Speed at Misfire | -- | 0 RPM | This parameter represents the engine RPM at the moment that the misfire diagnostic trouble code (DTC) was set. |
EVAP Purge Solenoid Command | -- | Varies, typically less than 30% | This parameter indicates in percent, the amount the pulse width modulated (PWM) evaporative emission (EVAP) canister purge solenoid is commanded ON, OPEN. |
EVAP Vacuum Leak Pump | -- | Off | This parameter indicates when the evaporative emission (EVAP) vacuum leak pump is ON or OFF. Normally the pump is turned ON when the EVAP system leak test diagnostic runs. The leak diagnostic runs after the engine has been turned off for 5 hours. |
EVAP Vent Solenoid Command | -- | Venting | This parameter displays the state of the EVAP vent solenoid as commanded by the control module. |
Exh. CMP Angle | -- | 0 Degrees | This parameter indicates the actual exhaust camshaft advance or retard in relative degrees. The displayed value is calculated from CMP sensor 2 and CKP sensor inputs. Normal Cam Phase Angle readings are 0 to 55 degrees. |
Exh. CMP Command | -- | 0% | The scan tool range is 0-100 percent. This parameter displays the duty cycle (DC) of the exhaust CMP actuator solenoid valve. A reading of less than xx percent indicates the PCM is retarding camshaft timing. A reading of 20 to 40 percent indicates the PCM is holding the camshaft timing at the current setting. A reading of more than xx percent indicates the PCM is advancing camshaft timing. |
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 | ||
Fuel Pump Relay Command | Ignition ON, engine OFF | Fuel pump ON for 2 seconds, then OFF | This parameter displays the control modules commanded state of the fuel pump relay control circuit. |
Engine idling | On | ||
Fuel Tank Pressure Sensor | Fuel Tank Fill Cap Removed | Varies, normally 3.5-3.8 Volts | This parameter displays the signal voltage of the FTP sensor. The voltage indicates the pressure/vacuum inside the fuel tank. A voltage less than 3.0 volts indicates a vacuum, while a voltage greater than 3.8 volts indicates a pressure. |
High Electrical Load | -- | No | This mode displays the status of the headlamp switch and the rear defogger switch. If one or more of the switches is ON, a signal is sent to the powertrain control module (PCM) to increase the engine idle speed due to the increased load. |
HO2S 1 | -- | Varies, typically 3.2-3.4 Volts | This parameter displays the output voltage of the air/fuel ratio oxygen sensor. The voltage should fluctuate within a range of 3.1-3.5 volts. A rich air/fuel mixture, low oxygen content, is indicated when the voltage is less than 3.3 volts. Conversely a lean air/fuel mixture, high oxygen content, is indicated when the voltage is more than 3.3 volts. |
-- | Varies, typically 1.0 Lambda | This parameter displays the lambda output from the HO2S to the control module. A lambda below 1.0 indicates a rich exhaust, while a lambda above 1.0 indicates a lean exhaust. | |
HO2S 2 | -- | Varies | This parameter displays the exhaust oxygen output voltage beyond the catalytic converter. This voltage will remain inactive or appear lazy within a range 100 mV, lean exhaust, and 900 mV, rich exhaust, when the system is operating in Closed Loop. |
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 1 Signal | -- | Approximately 11-13 Volts | This parameter displays B+ when the control module detects a voltage at the ignition 1 input terminal. |
Ign. Cycle Counter | -- | 0-400 Counts | This parameter indicates the total number of times the ignition coils fire for every 1,000 engine revolutions. |
Injector 1 Command | -- | 1.10-2.20 ms | This parameter indicates the amount of time the fuel injector solenoid valve is open. |
Load at Misfire | -- | 0.00 G/Rev | This is Freeze Frame data that is displayed and stored the moment a misfire DTC sets. |
Long Term FT | -- | -20% to +20% | This parameter displays the commanded Long Term Fuel Trim correction by the control module. |
Loop Status | -- | Closed Loop | The Loop Status parameter will display one of the following conditions: OPEN LOOP: The engine has not met all of the conditions necessary for Closed Loop operation. CLOSED LOOP: The powertrain control module (PCM) is using the oxygen sensors as feedback for fuel control. |
MAF Sensor | -- | 1.50-5.00 g/s | This parameter indicates the quantity of air entering the engine through the mass air flow (MAF) sensor. |
MIL Command | -- | Off | This parameter will indicate whether the malfunction indicator lamp (MIL) is illuminated due to a diagnostic trouble code (DTC) being set. |
Misfire Current Cyl 1-4 | -- | 0 | 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. |
Number of DTC(s) | -- | 0 | Indicates the number of malfunction indicator lamp (MIL) illuminating diagnostic trouble codes (DTCs) that are set. |
PNP Switch | -- | Park/Neutral | This parameter indicates the range selection of automatic transmission equipped vehicles. The parameter will display Park/Neutral for the Park or Neutral position of the gear selector. The parameter will display In Gear for the Reverse, Drive, or Low positions of the gear selector. |
Power Steering Switch | -- | Normal, with steering straight ahead | This parameter displays High Pressure whenever the steering wheel is turned right or left far enough to increase the power steering fluid pressure above a specified amount. This signal enables the PCM to adjust the engine idle in order to maintain acceptable engine performance. |
Short Term FT | -- | -20% to +20% | This parameter displays the short-term correction to the fuel delivery by the control module in response to oxygen sensor. 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 | -- | 8-14 Degrees | This parameter displays the powertrain control module (PCM) controlled value that is being used to control the spark timing. |
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. |
Starter Switch | Engine Cranking | Released | This parameter displays Cranking when the powertrain control module (PCM) is receiving a signal indicating that the engine starter motor is cranking. |
TAC Motor Closed Command | -- | Varies, normally less than 40% | This parameter displays a percentage that momentarily increases when the control module commands the throttle plate to close. |
TAC Motor Current | -- | Varies, normally less than 3.0 amps | This parameter displays the operating current of the TAC motor. |
TAC Motor Command | -- | 0% | This parameter displays a percentage that momentarily increases when the control module commands the throttle plate to open. |
TAC Motor Open Command | -- | Varies, normally less than 40% | This parameter displays a percentage that momentarily increases when the control module commands the throttle plate to open. |
Throttle Plate at Idle | -- | Yes | This parameter indicates Yes when the position of throttle body throttle plate is at idle or the default closed position. |
TCC Brake Pedal Switch | -- | Released | This parameter is used only on 4 speed automatic transmission equipped vehicles. When the brake pedal is applied, the torque converter clutch (TCC) brake switch sends a signal to the powertrain control module (PCM) in order to disengage the TCC. |
TCC Enable Solenoid Command | -- | Off | This parameter is used only on 4 speed automatic transmission equipped vehicles. The TCC Enable Solenoid Command indicates when the powertrain control module (PCM) is requesting the torque converter clutch (TCC) ON. |
Total Fuel Trim Average | -- | 0.25-0.75 Counts | Total Fuel Trim is a calculated value obtained by combining the Short Term FT and the Long Term FT together. The Total Fuel Trim value indicates how large a correction is necessary in order to keep the air/fuel mixture at the stoichiometrical 14.7:1 ratio. Total Fuel Trim values of + or - 25 percent indicate a fuel system that is operating near the limits of normal fuel control. Total Fuel Trim data is useful in diagnosing fuel system concerns and DTC P0171 or DTC P0172. |
Total Misfire Count | -- | 0 Counts | This parameter displays the total misfires for all the cylinders. |
TP Sensor | -- | 12-15% | This parameter displays the throttle plate position in percent, as indicated by the throttle position (TP) sensor 1. |
TP Sensor | -- | 0.8-1.0 Volts | This parameter displays the TP sensor 1 signal voltage to the control module. |
TP Sensor 2 | -- | 45-55% | This parameter displays the throttle plate position in percent as indicated by the throttle position (TP) sensor 2. |
TP Sensor 2 | -- | 2.30-2.40 Volts | This parameter displays the TP sensor 2 signal voltage to the control module. |
Vehicle Speed Sensor | -- | 0 Km/h 0 mph | This parameter displays the speed of the vehicle as calculated by the powertrain control module (PCM) from information received from the vehicle speed sensor (VSS). |
Output Control | Description | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
A/C Relay | Activates the A/C compressor clutch relay and cooling fan 1 relay. The normal commanded state of both relays is NONE. The A/C compressor relay status can be monitored on the scan tool data parameter A/C Relay Command. The PCM allows relay control when the following conditions are met:
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Cam Valve Timing | Activates the intake camshaft position (CMP) actuator solenoid valve. The normal commanded state of the CMP actuator solenoid is NONE. When commanded ON, the CMP actuator solenoid is operated at 100 percent duty cycle and the engine runs rough or stalls. The PCM allows CMP actuator solenoid control when the following conditions are met:
Operation of the CMP actuator solenoid can be monitored on the parameter Camshaft Phase Solenoid Command. The solenoid remains in the commanded state for a maximum 5 seconds until any of the following conditions occur:
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Check Mode | Check Mode engine operation enhances the PCM ability to detect certain engine control system malfunctions. When entering the output control, the default commanded state is NONE or NORMAL. In order to enter check mode operation refer to Service Bay Test in 1.8L (LAY) or Service Bay Test in 2.4L (LAX). Check mode operation can be monitored on the data parameter Diagnostic Mode. The PCM remains in the commanded state until cancelled by the scan tool or until the ignition switch is cycled. | ||||||||||||
Cooling Fan | Activates the engine cooling fan. The normal commanded state of the fan is NONE. The PCM allows cooling fan control when the following conditions are met:
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EVAP Purge Solenoid | Activates the evaporative emission (EVAP) canister purge valve. The normal commanded state is NONE. When commanded ON, the purge solenoid operates near 30-50 percent duty cycle. The solenoid remains in the commanded state for a maximum of 5 seconds, or until vehicle speed is detected. | ||||||||||||
EVAP Vacuum Leak Pump | Activates the EVAP vacuum leak pump located in the EVAP vacuum leak pump assembly. The normal commanded state is NONE. When commanded ON, the vacuum pump generates vacuum pressure. The pump remains in the commanded state for a maximum 5 seconds or until system pressure exceeds -39.8 mm Hg (-21.3 in H2O). | ||||||||||||
EVAP Vent Solenoid | Activates the EVAP vent solenoid located in the EVAP vacuum leak pump assembly. The normal commanded state is NONE. When commanded ON, the vent valve switches to non-venting. The solenoid remains in the commanded state for a maximum of 5 seconds, or until vehicle speed is detected. | ||||||||||||
EVAP Service Bay Test | Activates the EVAP purge solenoid, the EVAP vent solenoid, and the EVAP vacuum leak pump. Both EVAP solenoids and the vacuum leak pump are automatically sequenced on and off while vapor pressure in the EVAP system is monitored by the fuel tank pressure (FTP) sensor. The service bay test can take 2-8 minutes in order to run. The PCM allows the service bay test to run when the following conditions are met:
If after clearing codes or running a second test the scan tool displays Test Failed, the request for the service bay test has been rejected. Exit the test screen on the scan tool and turn OFF the ignition for 30 seconds, before attempting the service bay test again. For additional information on the EVAP Service Bay Test refer to Service Bay Test in 1.8L (LAY) or Service Bay Test in 2.4L (LAX). | ||||||||||||
Exhaust CMP Actuator | Activates the exhaust camshaft position (CMP) actuator solenoid valve. The normal commanded state of the CMP actuator solenoid is NONE. When commanded ON, the CMP actuator solenoid is operated at 100 percent duty cycle and the engine runs rough or stalls. The PCM allows CMP actuator solenoid control when the following conditions are met:
Operation of the CMP actuator solenoid can be monitored on the parameter Exh. CMP Command and the Exh. CMP Angle. The solenoid remains in the commanded state for a maximum 5 seconds or until any of the following conditions occur:
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Fuel Injector Modification | Enables fuel injector to INCREASE or DECREASE fuel delivery by changing fuel injector pulse width (PW). The PCM increases or decreases the PW in 1 percent increments as commanded. The commanded range is from -12 to +25 percent. The solenoid remains in the commanded state until cancelled by the scan tool or until engine speed exceeds 3,000 RPM. | ||||||||||||
Fan Relay 1 | Activates the cooling fan relay 1, relay 2 and relay 3. The normal commanded state of the fan relays are 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:
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Fuel Pump | Controls the fuel pump relay. The normal commanded state is NONE. When commanded ON, the PCM turns the fuel pump relay ON. If the engine is running, fuel pump command is disabled. The relay remains in the commanded state for a maximum 5 seconds or until any of the following conditions occur:
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Injector 1 | Enables/disables the cylinder by turning OFF the fuel injector to the cylinder. The fuel injector is normally enabled. The control module disables the fuel injector when the following conditions are met:
When DISABLE is selected, the control module turns the injector OFF for a maximum of 5 seconds. When the injector is disabled, Spark is fixed at 5 degrees and the engine will go to Open Loop fuel control. All misfire data list parameters will be fixed at their pre-test values. | ||||||||||||
Injector 2 | |||||||||||||
Injector 3 | |||||||||||||
Injector 4 | |||||||||||||
Misfire Graphic | Displays the accumulated misfires occurring in each cylinder in a bar graph. The scan tool allows for a reset of the misfire graph. |
