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 the accelerator pedal position. There are three sensors which are located within the APP module that are scaled differently. This is a type D DTC.

Conditions for Setting the DTC

    • The voltage is less than 0.25 volt on the APP 2 sensor.
    • The condition met for 2 seconds.

Action Taken When the DTC Sets

    • The input from the APP 2 sensor is ignored.
    • This DTC will not turn the Service Throttle Soon lamp ON by itself.
    • The throttle will operate normally as long as there is only one sensor malfunction present. If two different APP sensors have a malfunction, the Service Throttle Soon lamp will light and the PCM will limit the power. If three APP sensors have a malfunction present, the Service Throttle Soon lamp will light and the PCM will only allow the engine to operate at idle.

Conditions for Clearing the MIL/DTC

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

A scan tool reads the APP 2 position in volts and should read about 4.5 volts with the throttle closed and the ignition ON or at idle. The voltage should decrease at a steady rate as the throttle is moved toward WOT. Also, 90% pedal travel is acceptable for a correct APP operation. Scan the APP 2 sensor while depressing the accelerator pedal with the engine stopped and the ignition ON. The display should vary from about 4.5 volts when the throttle was closed to about 1.5 volts when the throttle is held at the Wide Open Throttle (WOT) position.

Test Description

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

  1. This step determines if P0222 is the result of a hard failure or an intermittent condition.

  2. This step checks the PCM and wiring.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing the DTCs, 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. Turn the ignition ON with the engine OFF.
  2. With the throttle closed, observe the APP 2 voltage on the Scan Tool.

Is the APP 2 voltage less than or equal to the specified value?

0.25V

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 any additional DTCs stored?

--

Go to the Applicable DTC Table

Go to Diagnostic Aids

4

  1. Disconnect the APP sensor electrical connector.
  2. Use the J 39200 in order to probe the APP 2, 5 volt reference circuit at the APP harness.

Is the APP 2 voltage greater than the specified value?

5V

Go to Step 5

Go to Step 6

5

Use the J 39200 in order to probe the APP 2 sensor signal circuit at the APP sensor harness.

Is the APP 2 voltage greater than the specified value?

5V

Go to Step 10

Go to Step 8

6

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

Was the 5 volt reference circuit open or shorted to ground?

--

Go to Step 13

Go to Step 7

7

Check the 5 volt reference circuit for a poor connection at the PCM and replace the terminal if necessary.

Did the terminal require a replacement?

--

Go to Step 13

Go to Step 12

8

  1. Turn the ignition OFF.
  2. Disconnect the PCM.
  3. Check the APP 2 signal circuit for an open, or a short to ground.
  4. If the APP 2 sensor signal circuit is open or shorted to ground, repair as necessary.

Was the APP 2 signal circuit open or shorted to ground?

--

Go to Step 13

Go to Step 9

9

Check the APP 2 sensor signal circuit for a poor connection at the PCM and replace terminal if necessary.

Did the terminal require replacement?

--

Go to Step 13

Go to Step 12

10

Check for a poor electrical connection at the APP sensor.

Was a repair performed?

--

Go to Step 13

Go to Step 11

11

Replace the APP module. Refer to APP Module Replacement .

Is the action complete?

--

Go to Step 13

--

12

Replace the PCM.

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

Is the action complete?

--

Go to Step 13

--

13

  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 14

Go to Step 2

14

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