P06A4

P06A4-SENSOR REFERENCE VOLTAGE 4 CIRCUIT LOW





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

This sensor supply circuit provides a 5-Volt supply to the Accelerator Pedal Position (APPS) 2 Sensor, Diesel Particulate Filter Pressure Sensor and the Transmission Pressure Sensor. The Powertrain Control Module (PCM) illuminates the MIL lamp immediately after the diagnostic runs and fails. The ETC lamp will also flash. During this time the customer will be in a limp home mode. The PCM will turn off the MIL lamp after the diagnostic runs and passes in four consecutive drive cycles.

- When Monitored:
With the ignition on, PCM powered.

- Set Condition:
Low voltage detected at the (F854) 5-Volt Supply circuit.





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

1. ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, record all Freeze frame data.
3. With the scan tool, erase DTCs.
4. Turn the ignition off for 75 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Perform the INTERMITTENT CONDITION diagnostic procedure. Intermittent Condition Test

2. CHECK THE APPS SENSOR 2




1. Ignition on.
2. Disconnect the Accelerator Pedal Position Sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.

3. Measure the voltage on the (F854) 5-Volt Supply circuit at the Accelerator Pedal Position Sensor harness connector.

Is the voltage reading between 4.9 and 5.1 Volts?

Yes

- Replace the Accelerator Pedal Position Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CHECK THE DIESEL PARTICULATE FILTER PRESSURE SENSOR




1. Disconnect the Diesel Particulate Filter Pressure Sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.

2. Measure the voltage on the (F854) 5-Volt Supply circuit at the Diesel Particulate Filter Pressure Sensor harness connector.

Is the voltage reading between 4.9 and 5.1 Volts?

Yes

- Replace the Diesel Particulate Filter Pressure Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 4

4. CHECK THE TRANSMISSION PRESSURE SENSOR
1. Disconnect the Transmission Pressure Sensor harness connector.

NOTE: Check connectors - Clean/repair as necessary.

2. Measure the voltage on the (F854) 5-Volt Supply circuit at the Transmission Pressure Sensor harness connector.

Is the voltage reading between 4.9 and 5.1 Volts?

Yes

- Replace the Transmission Pressure Sensor.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 5

5. CHECK THE (F854) 5-VOLT SUPPLY CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off.
2. Disconnect the PCM C2 harness connector.
3. Check connectors - Clean/repair as necessary.
4. Measure the resistance between ground and the (F854) 5-Volt Supply circuit at the Diesel Particulate Filter Pressure Sensor harness connector.

Is the resistance below 10k Ohms?

Yes

- Repair the (F854) 5-Volt Supply circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 6

6. CHECK FOR THE (F854) 5-VOLT SUPPLY CIRCUIT SHORTED TO ANOTHER CIRCUIT
1. Measure the resistance between the (F854) 5-Volt Supply circuit and all other circuits at the PCM C2 harness connector.

Is the resistance below 10k Ohms between the (F854) 5-Volt Supply circuit and any of the circuits?

Yes

- Repair the short to the circuit that measured below 10k Ohms.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

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