• | Perform the Diagnostic System Check - Vehicle prior to using this 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 |
---|---|---|---|---|
Engine Oil Pressure 5-Volt Reference Circuit | P0522 | P0522 | -- | P0521 |
Engine Oil Pressure Sensor Signal Circuit | P0522 | P0522 | P0523 | P0521 |
Low Reference | -- | P0523 | -- | P0521 |
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 the engine oil pressure 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 the serial data circuit. The IPC illuminates the engine oil pressure indicator when it receives a serial data message indicating a low engine oil pressure condition.
The engine is running.
• | The ECM detects that the EOP sensor signal circuit is greater than 4.8 volts. |
• | The above condition is present for greater than 10 seconds. |
• | The ECM records the operating conditions at the time the diagnostics test fails. The ECM displays this information in the Failure Records on the scan tool. |
• | The IPC illuminates the EOP indicator. |
• | The DTC becomes history when the conditions for setting the DTC are no longer present. |
• | The history DTC clears after 40 malfunction-free warm-up cycles. |
⇒ | If greater than the specified range, test the low reference circuit terminal A for an open/high resistance. If the circuit tests normal, replace the engine control module (ECM). |
⇒ | If greater than the specified range, test the 5-volt reference circuit terminal B for a short to voltage. If the circuit tests normal, replace the ECM. |
⇒ | If greater than the specified range, test the signal circuit terminal C for a short to voltage 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 ECM replacement, setup and programming |