| • | 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 Switch Signal  | 1  | P0520  | P0520  | --  | 
Engine Oil Pressure Switch Ground  | --  | P0520  | 1  | --  | 
1. Engine Oil Pressure Indicator Malfunction  | ||||
The engine oil pressure (EOP) switch is a normally closed switch that opens with the proper oil pressure. With the ignition switch turned ON and the engine not running, the engine control module (ECM) should detect a low signal voltage input. With the engine running, the pressure switch opens, and the ECM should detect a high signal voltage input. When the oil pressure is low, the ECM sends a serial data message to the body control module (BCM) requesting the EOP indicator turned ON. The IPC illuminates the EOP indicator when the IPC receives a serial data message from the BCM requesting the EOP indicator turned ON.
The ignition is ON, with the engine ON.
| • | The ECM detects that the EOP sensor signal circuit is pulled high. | 
| • | 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. | 
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 for the 2.0L engine. | 
| • | Oil Pressure Diagnosis and Testing for the 2.2L or 2.4L engine. | 
| ⇒ | If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the ECM. | 
| ⇒ | If not the specified value, test the signal circuit 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.
| • | Engine Oil Pressure Switch Replacement for the 2.0L engine | 
| • | Engine Oil Pressure Switch Replacement for the 2.2L or 2.4L engine | 
| • | Control Module References for the ECM replacement, setup, and programming |