The engine oil pressure (EOP) sensor changes resistance based on engine oil pressure. The ECM monitors the signal circuit from the EOP sensor. The engine control module (ECM) supplies 5-volts to the EOP sensor on the 5-volt reference circuit. The ECM also provides a ground on the low reference circuit. The EOP sensor provides a signal to the ECM on the EOP sensor signal circuit which is relative to the pressure changes in the engine oil pressure. When the oil pressure is high, the sensor resistance is high, and the ECM senses a high voltage. When the oil pressure is low, the sensor voltage is low, and the ECM senses a low signal voltage. The ECM sends the engine oil pressure information to the IPC (Dash) via the CAN BUS data circuit.

Schematic Reference

Engine Controls Schematics

Connector End View Reference

Electrical Information Reference

Scan Tool Reference

Engine Control Module Scan Tool Information

1. Engine running, observe the scan tool Engine Oil Pressure Sensor parameter. The reading should be between 41-448 kPa (6-65 psi).
2. Verify the engine oil pressure with a mechanical oil pressure gage. Verify the actual engine oil pressure is between 41-448 kPa (6-65 psi).

1. Ignition OFF, disconnect the harness connector at the EOP sensor.
2. Test for less than 5 ohms between the low reference circuit terminal A and ground.

⇒	If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal B and ground.

⇒	If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

⇒	If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. Verify the scan tool Engine Oil Pressure Sensor parameter is less than 8 kPa (1.2 psi).

⇒	If greater than the specified range, test the signal circuit terminal C for a short to voltage. If the circuit tests normal, replace the ECM.

5. Install a 3A fused jumper wire between the signal circuit terminal C and the 5-volt reference circuit terminal B. Verify the scan tool Engine Oil Pressure Sensor parameter is greater than 550 kPa (80 psi).

⇒	If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.

6. If all circuits test normal, test or replace the EOP sensor.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.