DTC Descriptor
DTC P060D: Control Module Accelerator Pedal Position (APP) System Performance
Diagnostic Fault Information
Always perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
Circuit/System Description
The throttle actuator control (TAC) system uses two accelerator pedal position (APP) sensors to monitor the pedal position. Two processors are also used to monitor the TAC system data. The engine control module (ECM) performs an intrusive test in order
to detect that the APP signals are not shorted together. The ECM accomplishes this by pulling the APP sensor 2 low momentarily and looking for sensor 1 to also be low. The TAC system also performs this test on the throttle position (TP) sensors.
This diagnostic monitors the transistor used to pull one pedal and one throttle sensor to ground simultaneously. Additionally, both processors monitor each other's data to verify that the indicated APP calculation is correct.
Conditions for Running the DTC
| • | The system voltage is more than 5.23 volts. |
| • | The ignition is in the Unlock/Accessory or Run position. |
| • | DTCs P0601, P0602, P0604, P0606, P0607 or P1621 are not set. |
Conditions for Setting the DTC
The APP sensor 2 voltage is more than 1.75 volts for more than 0.3 second during the intrusive test.
OR
The APP sensor calculations in the main processor differ from the motor control processor by more than 0.142 volt.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when
the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic
fails. The control module stores this information in the Freeze Frame and/or the Failure
Records. |
| • | The control module commands the TAC system to operate in the
Reduced Engine Power mode. |
| • | A message center or an indicator displays Reduced Engine Power. |
| • | Under certain conditions the control module commands the engine OFF. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL)
after 3 consecutive ignition cycles that the diagnostic runs and does
not fail. |
| • | A current DTC, Last Test Failed, clears when the diagnostic runs
and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles,
if no failures are reported by this or any other emission related diagnostic. |
| • | Clear the MIL and the DTC with a scan tool. |
Reference Information
Schematic Reference
Engine Controls Schematics
Connector End View Reference
Electrical Information Reference
Scan Tool Reference
Scan Tool Data List
Circuit/System Testing
- Clear the DTCs with the scan tool. Operate the vehicle within the Conditions for Running the DTC or within the conditions that you observed from the Freeze Frame/Failure Records.
- With the ignition ON, use a scan tool to observe the DTCs.
- With the ignition OFF, disconnect the accelerator pedal connector. Ensure that the pedal is at the rest position. Measure for more than 450 ohms from the 5-volt reference terminal of the accelerator pedal assembly to the APP sensor 2
signal terminal of the accelerator pedal assembly.
| ⇒ | If less than 450 ohms, replace the accelerator pedal assembly. |
- If the pedal test is normal, replace the ECM.
Repair Instructions
Important: Always perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
