• | 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 |
---|---|---|---|---|
Oil Pressure Switch Signal | 1 | P0520 | -- | -- |
1. Engine Oil Pressure Indicator Always On |
The engine control module (ECM) monitors the signal circuit of the engine oil pressure (EOP) sensor. When the oil pressure is high, the sensor is open, and the ECM senses a high signal voltage. When the oil pressure is low, the sensor is closed, and the ECM senses a low signal voltage.
The ignition is ON, with the engine ON.
• | The ECM detects that the EOP sensor signal circuit is pulled low. |
• | The above condition is present for greater than 5 seconds. |
• | The ECM records the operating conditions at the time the diagnostic test fails. The ECM displays this information in the Failure Records on the scan tool. |
• | The instrument panel cluster (IPC) illuminates the engine oil pressure 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. |
• | The ECM receives a clear code command from the scan tool. |
Using the Failure Records data may help locate an intermittent condition. If you cannot duplicate the DTC, the information in the Failure Records can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can help determine how many ignition cycles that the diagnostic test reported a pass and/or a fail.
⇒ | If not Low, test the signal circuit of the EOP switch for 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 |