• | Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
Oil Pressure Switch Signal | 1 | P0520 | 1 | -- |
Low Reference | -- | P0520 | -- | -- |
1. Engine Oil Pressure Indicator Malfunction |
With low oil pressure, the engine oil pressure (EOP) switch closes, and the signal circuit is low. With oil pressure above 4.5 psi, the EOP switch opens, and the signal circuit is high. The engine control module (ECM) monitors the oil pressure switch signal circuit, and sends a serial data message to the instrument panel cluster (IPC) indicating the switch status.
Control Module References for Scan Tool Information
Ignition ON, engine running, verify the scan tool Engine Oil Pressure Switch parameter is OK.
⇒ | If not the specified value, refer to Oil Pressure Diagnosis and Testing. |
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | If not the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM. |
⇒ | If not the specified value, test the signal circuit for an open/high resistance. If circuit test normal, replace the ECM. |
⇒ | If the engine oil pressure gage does not perform the IPC gages sweep test, replace the IPC. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for the IPC or ECM replacement, setup, and programming |
• | Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
Engine Oil Pressure 5-Volt Reference | P0522 | 1 | P0522 | P0523 | P0521 |
Engine Oil Pressure Sensor Signal | P0522 | 1 | P0522 | P0523 | P0521 |
Low Reference | -- | 1 | P0523 | -- | P0521 |
1. Engine Oil Pressure Indicator Malfunction |
The engine oil pressure (EOP) sensor changes voltage based on the engine oil pressure. The EOP sensor is a 3-wire sensor comprising of the signal circuit, the low reference circuit and the 5-volt reference circuit. The engine control module (ECM) supplies 5 volts to the EOP sensor via the 5-volt reference circuit and provides ground via the EOP low reference circuit. The ECM monitors the signal circuit of the EOP sensor to determine if the EOP sensor voltage is within the normal operating range of approximately 1-4 volts. When the engine oil pressure is high, the EOP sensor voltage is high and the ECM senses a high signal voltage. When the engine oil pressure is low, the EOP sensor voltage is low and the ECM senses a low signal voltage. The ECM sends the EOP information to the instrument panel cluster (IPC) via a serial data message. The ECM can also predict oil pressure as a function of engine speed and engine temperature.
Control Module References for scan tool information
⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | 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. |
⇒ | If greater than the specified range, test the signal circuit terminal 3 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM. |
⇒ | 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. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for the IPC and ECM replacement, setup, and programming |