P254D

P254D-PTO SPEED SELECTOR SENSOR CIRCUIT HIGH

For a complete wiring diagram refer to the Wiring Information Electrical Diagrams.

Theory of Operation

The remote accelerator pedal position sensor varies the signal voltage to the ECM as the remote accelerator pedal is depressed and released. Low signal voltage is received by the ECM when the remote accelerator lever is a 0%. A high signal voltage is received by the ECM when the remote accelerator is at 100%. The remote accelerator pedal position circuit contains a remote accelerator pedal position 5-volt supply, remote accelerator pedal position return and remote accelerator pedal signal. When the ECM senses a signal voltage lower than the normal operating range of the sensor, this fault is set. NOTE. The remote accelerator pedal or lever location varies with each original equipment manufacturer (OEM). Refer to the OEM troubleshooting and repair manual. The ECM will light the MIL lamp immediately after this diagnostic runs and fails. The ECM will turn off the MIL lamp after the diagnostic runs and passes in 4 consecutive drive cycles.

- When Monitored:
Key on.

- Set Condition:
The ECM detects that the remote accelerator pedal signal voltage is greater than 4.5 volts for more than 1 second.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure

1. OTHER DTC'S
1. Ignition on, engine not running.
2. With the scan tool, read DTC's.

Are there any sensor supply fault codes?

Yes

- Repair other DTC's first.

No

- Go To 2

2. P254D ACTIVE

Is P254D active?

Yes

- Go To 3

No

- Refer to the INTERMITTENT CONDITION - DIESEL diagnostic procedure.Intermittent Condition Test

3. OPEN CIRCUIT
1. Turn the ignition off.
2. Disconnect the remote accelerator pedal or lever position sensor from the harness.

NOTE: Check connectors - Clean/repair as necessary.

3. Ignition on, engine not running.
4. Measure the voltage from the accelerator pedal or lever position (K854) 5-volt supply circuit to the accelerator pedal or lever position (K400) return circuit at the sensor harness connector.

Is the measured voltage between 4.75 and 5.25 volts?

Yes

- Go To 4

No

- Go To 6

4. P254C ACTIVE
1. With the scan tool, read DTC's.

Is P245C active and P245D inactive?

Yes

- Go To 5

No

- Go To 6

5. P254D ACTIVE
1. Turn the ignition off.
2. Reconnect the remote accelerator pedal or lever position sensor from the harness.
3. Ignition on, engine not running.
4. With the scan tool, read DTC's.

Is DTC P254D active?

Yes

- Replace the remote accelerator pedal or lever.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Repair complete. The removal and installation of the connector corrected the failure.

6. (K400) RETURN CIRCUIT OPEN
1. Turn the ignition off.
2. Disconnect the remote accelerator pedal or lever position sensor from the harness.
3. Disconnect the C2 ECM harness connector.

NOTE: Check connectors - Clean/repair as necessary.

4. Measure the resistance between the C2 ECM harness connector (K400) return circuit and the remote accelerator pedal or lever harness connector (K400) return circuit.

Is the resistance less than 10 ohms?

Yes

- Go To 7

No

- Repair the open (K400) return circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

7. (K400) RETURN CIRCUIT SHORT TO OTHER CIRCUIT
1. Measure the resistance between the (K400) return circuit in the C2 ECM harness connector and all other circuits in the C2 ECM harness connector.

Is the measured resistance greater than 100k ohms?

Yes

- Go To 8

No

- Repair the (K400) return circuit shorted to another circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

8. ECM
1. Reconnect the C2 ECM harness connector.
2. Reconnect the remote accelerator pedal or lever position sensor from the harness.
3. Ignition on, engine not running.
4. With the scan tool, read DTC's.

Is DTC 254D stored?

Yes

- Repair complete. The removal and installation of the connector corrected the failure.

No

- Replace and program the Engine Control Module.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test