GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The accelerator pedal position (APP) module provides a voltage signal that changes relative to the accelerator pedal position. There are 3 sensors which are located within the APP module that are scaled differently.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

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

Action Taken When the DTC Sets

    • The control module stores the DTC information into memory when the diagnostic runs and fails.
    • The malfunction indicator lamp (MIL) will not illuminate.
    • The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
    • The driver information center, if equipped, may display a message.

Conditions for Clearing the DTC

    • 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 non-emission related diagnostic.
    • Clear the DTC with a scan tool.

Diagnostic Aids

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

A scan tool reads the APP 2 position in volts and should read approximately 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 wide open throttle (WOT). Also, 90 percent pedal travel is acceptable for 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 approximately 4.5 volts when the throttle is closed to approximately 1.5 volts when the throttle is held at the WOT position.

Test Description

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

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

  2. This step checks the PCM and the wiring.

Step

Action

Values

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

--

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Turn ON the ignition, with the engine OFF.
  2. With the throttle closed, observe the APP 2 voltage on the scan tool.

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

0.25 V

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 are stored, refer to those tables first.

Are any additional DTCs stored?

--

Go to Diagnostic Trouble Code (DTC) List

Go to Diagnostic Aids

4

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

Does the APP 2 voltage measure more than the specified value?

5 V

Go to Step 5

Go to Step 6

5

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

Does the APP 2 sensor signal voltage measure more than the specified value?

4.8 V

Go to Step 10

Go to Step 8

6

  1. Turn OFF the ignition.
  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 the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you perform a repair?

--

Go to Step 13

Go to Step 7

7

Check the 5-volt reference circuit for a faulty connection at the PCM and replace the terminal if necessary. Refer to Wiring Repairs in Wiring Systems.

Did you perform a repair?

--

Go to Step 13

Go to Step 12

8

  1. Turn OFF the ignition.
  2. Disconnect the PCM.
  3. Check the APP 2 signal circuit for a short to ground.
  4. If the APP 2 sensor signal circuit shorted to ground, repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you perform a repair?

--

Go to Step 13

Go to Step 12

9

Check for a faulty electrical connection at the APP sensor. Repair the connection as necessary. Refer to Wiring Repairs in Wiring Systems.

Did you perform a repair?

--

Go to Step 12

Go to Step 10

10

Replace the APP module. Refer to Accelerator Pedal Position Sensor Replacement .

Did you complete the replacement?

--

Go to Step 12

--

11

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 12

--

12

  1. Use a scan tool in order clear the DTCs.
  2. Start the engine.
  3. Allow the engine to idle until the normal operating temperature is reached.
  4. Select DTC and the Specific DTC function.
  5. Enter the DTC number that was set.
  6. Operate the vehicle within the Conditions for Setting this DTC until the scan tool indicates the diagnostic ran.

Does the scan tool indicate the diagnostic passed?

--

Go to Step 13

Go to Step 2

13

Does the scan tool display any additional undiagnosed DTCs?

--

Go to Diagnostic Trouble Code (DTC) List

System OK