P2121
P2121-PPS CONFORMANCE ERRORP2121 - PPS Conformance Sensor:
WHEN MONITORED
While the engine is running
SET CONDITION
The ECM detected a conformance error between PPS 1 and PPS 2
POSSIBLE CAUSES
- Other DTC's
- Wiring harness or connector damaged
- APPS
- Intermittent condition
- ECM
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.
Diagnostic Test
1. OTHER DTC'S PRESENT
Using the scan tool, check for any additional APPS fault codes
Q: Do you have any additional APPS faults?
YES: troubleshoot other DTC's first, Go To 2
NO: Go To 12
2. APPS HARNESS
Verify that the APPS is connected.
Inspect the harness and the APPS connector.
Q: Are any pins damaged?
YES: Repair or replace the harness.
NO: Go To 3
3. APPS
Monitor the APPS 1 and APPS 2 voltage with the scan tool while depressing the accelerator pedal.
Q: 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 To 4
NO: Replace the APPS. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
4. OPEN SIGNAL CIRCUIT
Disconnect the ECM connectors.
Disconnect the APPS connector.
NOTE: Check connectors - Clean/repair as necessary.
Measure the resistance of the APPS 1 signal circuit between the APPS sensor connector and the ECM connector.
YES: Go To 5
NO: Repair or Replace the harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
5. OPEN SUPPLY CIRCUIT
Measure the resistance of the APPS 1 supply circuit between the APPS sensor connector and the ECM connector.
Q: Is the resistance less than 10 ohms?
YES: Go To 6
NO: Repair or replace the open harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
6. SIGNAL CIRCUIT SHORTED TO GROUND
Measure the resistance between the APPS 1 signal circuit at the sensor connector and battery negative.
Q: Is the resistance greater than 100 K ohms?
YES: Go To 7
NO: Repair the shorted harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
7. 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.
Q: Is the resistance greater than 100 K ohms?
YES: Go To 8
NO: Repair the shorted signal circuit. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
8. SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between the APPS 1 supply circuit at the sensor connector and battery negative.
Q: Is the resistance greater than 100 K ohms?
YES: Go To 9
NO: Repair the Supply circuit shorted to ground. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
9. SUPPLY CIRCUIT SHORTED TO OTHER CIRCUITS
Measure the resistance between the APPS 1 supply circuit at the ECM connector and all other circuits in the ECM connector.
Q: Is the resistance greater than 100 K ohms?
YES: Go To 10
NO: Repair the supply circuit shorted to other circuits. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
10. RETURN CIRCUIT OPEN
Measure the resistance on the APPS 1 return circuit between the sensor connector and the ECM connector.
Q: Is the resistance less than 10 ohms?
YES: Go To 11
NO: Repair the open return circuit. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
11. SIGNAL CIRCUIT SHORTED TO SUPPLY CIRCUIT
Measure the resistance between the APPS 1 signal circuit in the sensor connector and the PPS 1 supply circuit in the sensor connector.
Q: Is the resistance greater than 100 K ohms?
YES: Go To 12
NO: Repair the signal circuit shorted to the supply. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
12. RETURN CIRCUIT SHORTED TO OTHER CIRCUITS
Measure the resistance between the 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 the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
13. OPEN SIGNAL CIRCUIT
Measure the resistance of the APPS 2 signal circuit between the APPS sensor connector and the ECM connector.
YES: Go To 14
NO: Repair or Replace the harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
14. OPEN SUPPLY CIRCUIT
Measure the resistance of the APPS 2 supply circuit between the APPS sensor connector and the ECM connector.
Q: Is the resistance less than 10 ohms?
YES: Go To 15
NO: Repair or replace the open harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
15. SIGNAL CIRCUIT SHORTED TO GROUND
Measure the resistance between the APPS 2 signal circuit at the sensor connector and battery negative.
Q: Is the resistance greater than 100 K ohms?
YES: Go To 16
NO: Repair the shorted harness. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
16. SIGNAL CIRCUIT SHORTED TO OTHER CIRCUITS
Measure the resistance between the APPS 2 signal circuit at the ECM connector and all other circuits in the ECM connector.
Q: Is the resistance greater than 100 K ohms?
YES: Go To 17
NO: Repair the shorted signal circuit. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
17. SUPPLY CIRCUIT SHORTED TO GROUND
Measure the resistance between the APPS 2 supply circuit at the sensor connector and battery negative.
Q: Is the resistance greater than 100 K ohms?
YES: Go To 18
NO: Repair the Supply circuit shorted to ground. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
18. SUPPLY CIRCUIT SHORTED TO OTHER CIRCUITS
Measure the resistance between the APPS 2 supply circuit at the ECM connector and all other circuits in the ECM connector.
Q: Is the resistance greater than 100 K ohms?
YES: Go To 19
NO: Repair the supply circuit shorted to other circuits. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
19. RETURN CIRCUIT OPEN
Measure the resistance on the APPS 2 return circuit between the sensor connector and the ECM connector.
Q: Is the resistance less than 10 ohms?
YES: Go To 20
NO: Repair the open return circuit. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
20. SIGNAL CIRCUIT SHORTED TO SUPPLY CIRCUIT
Measure the resistance between the APPS 2 signal circuit in the sensor connector and the PPS 2 supply circuit in the sensor connector.
Q: Is the resistance greater than 100 K ohms?
YES: Go To 21
NO: Repair the signal circuit shorted to the supply. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
21. RETURN CIRCUIT SHORTED TO OTHER CIRCUITS
Measure the resistance between the 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 the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
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.
Q: Did a APPS 1 and APPS 2 voltage too low DTC set?
YES: Go To 23
NO: Replace the ECM. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1
23. APPS
Reconnect the APPS connector.
Monitor the APPS 1 and APPS 2 voltage with the scan tool while depressing the accelerator pedal.
Q: 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 Symptom (Diagnostic Procedure).
NO: Replace the APPS. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1