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P0652






P0652-SENSOR REFERENCE VOLTAGE 2 LOW

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:
With the key on.

- Set Condition:
Voltage detected on the 5-volt supply circuit is below 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. CAMSHAFT POSITION SENSOR




1. Turn the ignition off.
2. Disconnect the Camshaft Position Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (F855) 5-volt Supply circuit at the Camshaft Position Sensor harness connector.

Is the voltage reading between 4.9 and 5.1 volts?

Yes

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

No

- Go To 3

3. INLET AIR TEMPERATURE/PRESSURE SENSOR




1. Turn the ignition off.
2. Disconnect the Inlet Air Temperature/Pressure Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (F855) 5-volt Supply circuit at the Inlet Air Temperature/Pressure Sensor harness connector.

Is the voltage reading between 4.9 and 5.1 volts?

Yes

- Replace the Inlet Air Temperature/Pressure Sensor.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 4

4. EXHAUST PRESSURE SENSOR




1. Turn the ignition off.
2. Disconnect the Exhaust Pressure Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (F855) 5-volt Supply circuit at the Inlet Exhaust Pressure Sensor harness connector.

Is the voltage reading between 4.9 and 5.1 volts?

Yes

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

No

- Go To 5

5. FUEL RAIL PRESSURE SENSOR




1. Turn the ignition off.
2. Disconnect the Fuel Rail Pressure Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (F855) 5-volt Supply circuit at the Fuel Rail Pressure Sensor harness connector.

Is the voltage reading between 4.9 and 5.1 volts?

Yes

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

No

- Go To 6

6. BOOST PRESSURE/CAC TEMPERATURE SENSOR




1. Turn the ignition off.
2. Disconnect the Boost Pressure/CAC Temperature Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (F855) 5-volt Supply circuit at the Boost Pressure/CAC Temperature Sensor harness connector.

Is the voltage reading between 4.9 and 5.1 volts?

Yes

- Replace the Boost Pressure/CAC Temperature Sensor.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 7

7. EGR VALVE




1. Turn the ignition off.
2. Disconnect the EGR Valve harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (F855) 5-volt Supply circuit at the EGR Valve harness connector.

Is the voltage reading between 4.9 and 5.1 volts?

Yes

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

No

- Go To 8

8. FAN SPEED SENSOR




1. Turn the ignition off.
2. Disconnect the Fan Clutch Assembly harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (F855) 5-volt Supply circuit at the Fan Clutch Assembly harness connector.

Is the voltage reading between 4.9 and 5.1 volts?

Yes

- Replace the Fan Clutch Assembly.
- Perform POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test

No

- Go To 9

9. CRANKCASE PRESSURE SENSOR




1. Turn the ignition off.
2. Disconnect the Crankcase Pressure Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (F855) 5-volt Supply circuit at the Crankcase Pressure Sensor harness connector.

Is the voltage reading between 4.9 and 5.1 volts?

Yes

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

No

- Go To 10

10. (F855) 5-VOLT SUPPLY SHORTED TO GROUND




1. Disconnect the ECM C1 harness connector.
2. Measure the resistance between ground and the (F855) 5-volt Supply circuit at the ECM C1 harness connector.

Is the resistance below 10k ohms?

Yes

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

No

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