P0653

P0653-SENSOR REFERENCE VOLTAGE 2 HIGH

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

Theory of Operation

This sensor supply circuit provides a 5-volt supply to: Camshaft Position Sensor, Inlet Air Temperature/Pressure Sensor, Exhaust Pressure Sensor, Fuel Pressure Sensor, Boost Pressure/CAC Temperature, EGR Valve, Fan Clutch Assembly, and Crankcase Pressure Sensor. A MIL lamp will be lit immediately after this diagnostic runs and fails. The MIL lamp will turn off once the diagnostic runs and passes in 4 consecutive drive cycles.

- When Monitored:
While the engine is running.

- Set Condition:
Voltage detected on the 5-volt supply circuit is above a calibrated value.





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 30 seconds.
5. Turn the ignition on.
6. With the scan tool, read DTCs.

Did the DTC reset?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION - DIESEL (Diagnostic Procedure). Intermittent Condition Test

2. (F855) 5-VOLT SUPPLY SHORTED TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the connectors for each component listed in the Theory Of Operation.
3. Turn the ignition on.
4. Measure the voltage of the (F855) 5-volt Supply circuit at any of the disconnected component harness connectors.

Is the voltage reading above 5.5 volts?

Yes

- Repair the short to voltage in the (F855) 5-volt Supply circuit.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 3

3. (F855) 5-VOLT SHORTED
1. Turn the ignition off.
2. Disconnect the ECM C1 harness connector.

NOTE: Check connectors - Clean/repair as necessary.

3. Measure the resistance between the (F855) 5-volt Supply circuit and all other circuits in the ECM C1 connector.

Is the resistance less than 10k ohms between the (F855) 5-volt Supply circuit and any of the circuits?

Yes

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

No

- Replace the ECM.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test