P2121

P2121-PPS CONFORMANCE ERROR

For complete wiring diagrams refer to Diagrams/Electrical.

- When Monitored:

While the engine is running

- Set Condition:

The ECM detected a conformance error between PPS 1 and PPS 2

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. OTHER DTCS PRESENT

NOTE: Diagnose all other APPS faults before continuing.

Do you have any additional APPS faults?

Yes

- Go To 2

No

- Go To 12

2. APPS HARNESS

Verify that the APPS is connected.

Inspect the harness and the APPS connector.

Are any pins damaged?

Yes

- Repair or replace the harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 3

3. APPS

Monitor the APPS 1 and APPS 2 voltage with the scan tool while depressing the accelerator pedal.

Is the voltage transition shown on the scan tool smooth while depressing the accelerator pedal and is the voltage from APPS 1 twice as much as the voltage from APPS 2?

Yes

- Go To4

No

- Replace the APPS.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

4. (K23) APPS SIGNAL CIRCUIT OPEN

Disconnect the ECM connectors.

Disconnect the APPS connector.

NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance of the (K23) APPS 1 Signal circuit between the APPS sensor connector and the ECM connector.

Is the resistance below 5.0 ohms?

Yes

- Go To5

No

- Repair or Replace the harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

5. (K852) 5-VOLT SUPPLY CIRCUIT OPEN

Measure the resistance of the (K852) 5-volt Supply circuit between the APPS sensor connector and the ECM connector.

Is the resistance less than 10 ohms?

Yes

- Go To6

No

- Repair or replace the open harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

6. (K23) APPS 1 SIGNAL CIRCUIT SHORTED TO GROUND

Measure the resistance between the (K23) APPS 1 Signal circuit at the sensor connector and battery negative.

Is the resistance greater than 100 K ohms?

Yes

- Go To 7

No

- Repair the shorted harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

7. (K23) APPS 1 SIGNAL CIRCUIT SHORTED TO OTHER CIRCUITS

Measure the resistance between the APPS 1 signal circuit at the ECM connector and all other circuits in the ECM connector.

Is the resistance greater than 100 K ohms?

Yes

- Go To 8

No

- Repair the shorted signal circuit.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

8. (K852) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND

Measure the resistance between the (K852) 5-volt supply circuit at the sensor connector and battery negative.

Is the resistance greater than 100 K ohms?

Yes

- Go To 9

No

- Repair the Supply circuit shorted to ground.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

9. (K852) 5-VOLT SUPPLY CIRCUIT SHORTED TO OTHER CIRCUITS

Measure the resistance between the (K852) 5-volt Supply circuit at the ECM connector and all other circuits in the ECM connector.

Is the resistance greater than 100 K ohms?

Yes

- Go To 10

No

- Repair the supply circuit shorted to other circuits.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

10. (K167) APPS 1 RETURN CIRCUIT OPEN

Measure the resistance on the (K167) APPS 1 Return circuit between the sensor connector and the ECM connector.

Is the resistance less than 10 ohms?

Yes

- Go To 11

No

- Repair the open return circuit.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

11. (K23) APPS 1 SIGNAL CIRCUIT SHORTED TO (K852) 5-VOLT SUPPLY CIRCUIT

Measure the resistance between the (K23) APPS 1 Signal circuit and the (K852) 5-volt Supply circuit in the sensor connector.

Is the resistance greater than 100 K ohms?

Yes

- Go To 12

No

- Repair the signal circuit shorted to the supply.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

12. (K167) APPS 1 RETURN CIRCUIT SHORTED TO OTHER CIRCUITS

Measure the resistance between the (K167) APPS 1 Return circuit at the ECM connector and all other circuits in the ECM connector.

Yes

- Go To 13

No

- Repair the return circuit shorted to other circuits.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

13. (K29) APPS 2 SIGNAL CIRCUIT OPEN

Measure the resistance of the (K29) APPS 2 Signal circuit between the APPS sensor connector and the ECM connector.

Theory of Operation

Yes

- Go To14

No

- Repair or Replace the harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

14. (F854) 5-VOLT SUPPLY CIRCUIT OPEN

Measure the resistance of the (K854) APPS 2 Supply circuit between the APPS sensor connector and the ECM connector.

Is the resistance less than 10 ohms?

Yes

- Go To15

No

- Repair or replace the open harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

15. (K29) APPS 2 SIGNAL CIRCUIT SHORTED TO GROUND

Measure the resistance between the (K29) APPS 2 Signal circuit at the sensor connector and battery negative.

Is the resistance greater than 100 K ohms?

Yes

- Go To 16

No

- Repair the shorted harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

16. (K29) APPS 2 SIGNAL CIRCUIT SHORTED TO OTHER CIRCUITS

Measure the resistance between the (K29) APPS 2 Signal circuit at the ECM connector and all other circuits in the ECM connector.

Is the resistance greater than 100 K ohms?

Yes

- Go To 17

No

- Repair the shorted signal circuit.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

17. (K854) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND

Measure the resistance between the (K854) 5-volt Supply circuit at the sensor connector and battery negative.

Is the resistance greater than 100 K ohms?

Yes

- Go To 18

No

- Repair the Supply circuit shorted to ground.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

18. (K854) 5-VOLT SUPPLY CIRCUIT SHORTED TO OTHER CIRCUITS

Measure the resistance between the (K854) 5-volt Supply circuit at the ECM connector and all other circuits in the ECM connector.

Is the resistance greater than 100 K ohms?

Yes

- Go To 19

No

- Repair the supply circuit shorted to other circuits.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

19. (K400) APPS 2 RETURN CIRCUIT OPEN

Measure the resistance on the (K400) APPS 2 Return circuit between the sensor connector and the ECM connector.

Is the resistance less than 10 ohms?

Yes

- Go To 20

No

- Repair the open return circuit.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

20. (K29) APPS 2 SIGNAL CIRCUIT SHORTED TO THE (K854) 5-VOLT SUPPLY CIRCUIT

Measure the resistance between the (K29) APPS 2 Signal circuit and the (K854) 5-volt Supply circuit in the sensor connector.

Is the resistance greater than 100 K ohms?

Yes

- Go To 21

No

- Repair the signal circuit shorted to the supply.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

21. (K400) APPS 2 RETURN CIRCUIT SHORTED TO OTHER CIRCUITS

Measure the resistance between the (K400) APPS 2 Return circuit at the ECM connector and all other circuits in the ECM connector.

Yes

- Go To 22

No

- Repair the return circuit shorted to other circuits.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

22. ECM

Reconnect the ECM connectors.

Reconnect the APPS connector.

Turn Ignition on, engine off.

While monitoring with the scan tool, disconnect the sensor connector.

Did a APPS 1 and APPS 2 voltage too low DTC set?

Yes

- Go To 23

No

- Replace the ECM.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

23. APPS

Reconnect the APPS connector.

Monitor the APPS 1 and APPS 2 voltage with the scan tool while depressing the accelerator pedal.

Is the voltage transition shown on the scan tool smooth while depressing the accelerator and is the voltage from APPS 1 twice as much as the voltage from APPS 2?

Yes

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition

No

- Replace the APPS.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test