GM Service Manual Online
For 1990-2009 cars only

Object Number: 592177  Size: MF
Engine Controls Components
Handling ESD Sensitive Parts Notice
Accelerator Pedal Position Sensor, Cruise Switch Input, Stoplamp and Clutch Pedal Switches
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The accelerator pedal position (APP) module provides a voltage signal that changes relative to accelerator pedal position. There are three sensors located within the APP module that are scaled differently.

Conditions for Running the DTC

    • The PCM performs this DTC diagnostic continuously.
    • The ignition switch in the ON position.

Conditions for Setting the DTC

    • The reference voltage on the APP 3 sensor is less than 4.8 volts.
    • All of the diagnostic set conditions met for 2 seconds.

Action Taken When the DTC Sets

    • The PCM will turn ON the Service Throttle Soon lamp and limit power.
    • Multiple DTCs will be present.

Conditions for Clearing the MIL/DTC

    • A History DTC clears after forty consecutive warm-up cycles, if this or any other emission related diagnostic does not report any failures.
    • The use of a scan tool.

Diagnostic Aids

An intermittent may be caused by the following:

    • Poor connections
    • Rubbed through wire insulation
    • Broken wire inside the insulation

All 5 volt reference circuits must be checked for proper reference voltage. Voltmeter accuracy is important.

Test Description

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

  1. This step will check all 5 volt reference circuits.

Step

Action

Values

Yes

No

1

Important: Before clearing the DTCs, use the scan tool Capture Info to save the Freeze Frame and failure records for reference. The control modules data is deleted once the Clear Info function is used.

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

  1. Disconnect the APP sensor electrical connector.
  2. Turn the ignition ON with the engine OFF.
  3. With a DMM connected to ground, check all the APP 5 volt reference circuits at the APP harness connector.

Is the voltage less than the specified value?

4.8 V

Go to Step 5

Go to Step 3

3

Are any other APP DTCs set?

--

Go to applicable DTC

Go to Step 4

4

The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If additional DTCs were stored, refer to the applicable DTC tables first.

Are any additional DTCs stored?

--

Go to applicable DTC

Go to Diagnostic Aids

5

  1. Turn the ignition OFF.
  2. Disconnect the PCM and check the 5 volt reference circuit for a short to ground.
  3. If the 5 volt reference circuit is shorted to ground, repair it as necessary.

Was the 5 volt reference circuit shorted to ground?

--

Go to Step 7

Go to Step 6

6

Important: The new PCM must be programmed.

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 7

--

7

  1. Using the scan tool, clear the DTCs.
  2. Start the engine.
  3. Allow the engine to idle at normal operating temperature.
  4. Select DTC and the Specific DTC function.
  5. Enter the DTC number which was set.
  6. Operate the vehicle, with the Condition for Setting this DTC, until the scan tool indicates the diagnostic Ran.

Does the scan tool indicate the diagnostic Passed?

--

Go to Step 8

Go to Step 2

8

Does the scan tool display any additional undiagnosed DTCs?

--

Go to applicable DTC

System OK