P2123

P2123-PPS 1 VOLTAGE TOO HIGH





For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

While the key is on and during engine operation.

- Set Condition:

The APPS signal circuit voltage at the ECM goes above 4.24 volts for more than 2 seconds.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test


1. (K167) APPS NO. 1 RETURN CIRCUIT OPEN





Turn the ignition off.

Disconnect the APPS harness connector.

Disconnect the ECM harness connectors.


NOTE: Check connectors - Clean/repair as necessary.

Measure the resistance on the (K167) APPS No. 1 return circuit between the sensor harness connector and the ECM harness connector.

Is the resistance less than 10 ohms?

Yes

- Go To 2

No

- Repair the (K167) APPS No. 1 return circuit open.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

2. (K23) APPS NO. 1 SIGNAL CIRCUIT SHORTED TO (K852) APPS NO. 1 5-VOLT SUPPLY





Measure the resistance between the (K23) APPS No. 1 signal circuit in the sensor harness connector and the (K852) APPS No. 1 5-volt supply circuit in the sensor harness connector.

Is the resistance greater than 100 K ohms?

Yes

- Go To 3

No

- Repair the (K23) APPS No. 1 signal circuit shorted to the (K852) 5-volt supply circuit.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

3. (K23) APPS SIGNAL CIRCUIT SHORTED TO ANOTHER CIRCUIT





Measure the resistance between the APPS No. 1 signal circuit at the ECM harness connector and all other circuits in the ECM harness connector.

Is the resistance greater than 100 k ohms?

Yes

- Go To 4

No

- Repair the (K23) APPS No. 1 signal circuit shorted to another circuit in the engine harness.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

4. ECM

Reconnect the ECM harness connectors.

Reconnect the APPS harness connector.

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

Did a APPS No. 1 and APPS No. 2 voltage too low DTC set?

Yes

- Go To 5

No

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

5. APPS

Reconnect the APPS harness connector.

Monitor the APPS No. 1 and APPS No. 2 voltage with the scan tool while depressing the throttle pedal.

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

Yes

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Intermittent Condition

No

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