P0653

P0653-HIGH VOLTAGE AT THE #1 SENSOR SUPPLY CIRCUIT

P0653 - High Voltage At The #1 Sensor Supply Circuit:

WHEN MONITORED
While the engine is running.

SET CONDITION
Voltage detected on the sensor supply is above a calibrated value.

POSSIBLE CAUSES
- ECM
- (F855) 5-Volt supply shorted to voltage
- Intermittent condition

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test

1. ECM





Turn the ignition off.
Disconnect the ECM 60 pin harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Turn the ignition on.
Measure the voltage between the Sensor (F855) #1 5-volt Supply and the Sensor #1 Return pin at the ECM.

Q: Is the voltage between 4.5 and 5.5 volts?

YES: Go To 2
NO: Replace and program the ECM in accordance with the Service Information. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

2. (F855) 5-VOLT SUPPLY SHORTED TO VOLTAGE





Key off.
Disconnect the sensor connectors for each pressure sensor, and the engine position sensor.
Disconnect the ECM 50 way harness connector.

NOTE: Check connectors - Clean/repair as necessary.

Ignition on, engine off.
Measure the voltage between the supply circuit at each pressure sensor harness connector and battery negative.
Measure voltage between the (F853) 5-volt supply circuit at the engine position sensor harness connector and battery negative.

Q: Is the voltage less than 1 volt?

YES: Go To 3
NO: Repair the (F855) 5-volt supply shorted to voltage. Perform the POWERTRAIN VERIFICATION TEST VER - 1 (DIESEL). Powertrain Verification Test - Ver 1

3. SENSOR SUPPLY SHORTED TO VOLTAGE IN HARNESS





Measure the resistance between the #1 sensor supply circuit and all other circuit in the ECM connectors.

Q: Is the resistance less than 10 ohms?

YES: Refer to the INTERMITTENT CONDITION Symptom (Diagnostic Procedure).
NO: Repair the harness shorted to voltage.