GM Service Manual Online
For 1990-2009 cars only

Object Number: 64733  Size: LF
Engine Controls Components
Cruise Control and Wastegate Controls
OBD II Symbol Description 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. This is a type D DTC.

Conditions for Setting the DTC

    • The reference voltage on APP 2 less than 4.8 volts.
    • The condition met for 2 seconds.

Action Taken When the DTC Sets

If DTC P0220 is stored, the PCM will turn ON the Service Throttle Soon lamp and limit power.

Conditions for Clearing the MIL/DTC

    • A History DTC will clear after forty consecutive warm-up cycles during which the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from the start up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle).
    • Use of a Scan tool will clear the DTC codes.

Diagnostic Aids

There are no driveability issues associated with the APP module unless a DTC is present. The most likely cause of this DTC are poor connections or the sensor itself. The least likely is a PCM problem.

All 5 volt reference circuits must be checked for a proper reference voltage. The voltmeter accuracy is important.

Test Description

The number(s) below refer to the step number(s) on the Diagnostic Table.

  1. This step will determine if there is a good voltage reference.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing the DTC(s), use the scan tool Capture Info in order to record the Freeze Frame and the failure records for reference, as the data will be lost when the Clear Info function is used.

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

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 J 39200 connected to ground, check all of the APP 5 volt reference circuits at the APP harness.

Is the voltage less than the specified value?

4.8V

Go to Step 4

Go to Step 3

3

The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If any additional DTCs were stored, refer to those table(s) first.

Are there additional DTC(s) stored?

--

Go to the Applicable DTC Table

Go to Diagnostic Aids

4

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

Was the 5 volt reference circuit shorted to ground?

--

Go to Step 6

Go to Step 5

5

Replace the PCM.

Important: The new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 6

--

6

  1. Use the Scan Tool in order to select DTC, Clear Info.
  2. Start the engine.
  3. Allow the engine to idle at the normal operating temperature.
  4. Select DTC, Specific, then enter the DTC number which was set.
  5. Operate the vehicle until the Scan Tool indicates that the diagnostic Ran.

Does the Scan Tool indicate that this diagnostic Passed?

--

Go to Step 7

Go to Step 2

7

Use the Scan Tool in order to select Capture Info, Review Info.

Are there any DTCs displayed that have not been diagnosed?

--

Go to the Applicable DTC Table

System OK