GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The accelerator pedal position (APP) sensors are mounted on the accelerator pedal/TAC module assembly. There are three individual accelerator pedal position sensors within one housing. Three separate signal, ground and reference circuits are used which are contained within the throttle actuator control (TAC) module. The APP sensor signal voltage increases as the Accelerator pedal is depressed. The signal circuits pull to ground within the TAC module.

Conditions for Running the DTC

    • DTCs P0606, P1517, P1518 are not set.
    • The ignition switch is in the crank or run position.

Conditions for Setting the DTC

APP sensor 3 voltage is less than 0.68 volts or more than 4.5 volts.

Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

Conditions for Clearing the MIL/DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Important: :  Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

When the TAC module detects a problem within the ETC System the PCM receives a message across serial data and more than one ETC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing captured DTC info.

If the DTC is determined to be intermittent, reviewing the Fail Records can be useful in determining when the DTC was last set.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. When the TAC module detects a problem within the ETC System the PCM receives a message across serial data and more than one ETC System related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual problem may correct more than one DTC. Keep this in mind when reviewing captured DTC info.

DTC P1275, 80, 85 -- Accelerator Pedal Position (APP) Sensor Circuit

Step

Action

Values

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Important: If any other DTCs are also set, refer to the appropriate DTC for further diagnosis.

  1. Turn ON the ignition, with your foot OFF the accelerator pedal and the engine OFF.
  2. With the scan tool, observe the APP sensor voltage parameter for this APP.

Does the scan tool indicate voltage within the specified range?

0.7-1.1 V

Go to Step 3

Go to Step 5

3

Fully depress the accelerator pedal.

Does the scan tool indicate the voltage within the specified range?

2.7-4.2 V

Go to Step 4

Go to Step 5

4

  1. With the scan tool, select Diagnostic Trouble Codes (DTCs).
  2. Depress the accelerator pedal to wide open throttle (WOT) and then return it to closed throttle.

Did this DTC fail this ignition?

--

Go to Step 5

Go to Diagnostic Aids

5

Replace the TAC module. Refer to Accelerator Pedal Replacement .

Did you complete the replacement?

--

Go to Step 6

--

6

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Fail Records conditions.

Does the DTC reset?

--

Go to Step 2

Go to Step 7

7

Does the scan tool indicate any DTCs set that you have not diagnosed?

--

Go to applicable DTC

System OK