GM Service Manual Online
For 1990-2009 cars only

Circuit 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. Both processors monitor each other's data to verify that the indicated APP calculation is correct.

If the indicated APP calculation is incorrect , DTC P060D sets.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P060D Control Module Accelerator Pedal Position (APP) System Performance

Conditions for Running the DTC

    • The system voltage is more than 5.23 volts.
    • The ignition is in Unlock/Accessory or Run position.
    •  DTCs P0601, P0602, P0604, P0606, P0607 or P1621 are not set.

Conditions for Setting the DTC

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.

Test Description

The number below refers to the step number on the diagnostic table.

  1. A DTC P0602 indicates that the ECM is not programmed.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Is DTC P0602 set?

--

Go to Step 3

Go to Step 5

3

Program the engine control module (ECM). Refer to Service Programming System (SPS) .

Does DTC P0602 reset?

--

Go to Step 4

Go to Step 6

4

  1. Ensure that all tool connections are secure.
  2. Ensure that the programming equipment is operating correctly.
  3. Ensure that the correct software/calibration package is used.
  4. Attempt to program the ECM. Refer to Service Programming System (SPS) .

Does DTC P0602 reset?

--

Go to Step 5

Go to Step 6

5

Replace the ECM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 6

--

6

  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 7

7

Observe the Capture Info with a scan tool.

Are there any DTCs that have not been diagnosed?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK