| • | 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  | --  | 
Low Reference  | --  | 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 instrument panel cluster (IPC) requesting the EOP indicator turned ON.
The engine is running.
| • | The ECM detects that the EOP sensor signal circuit is pulled low. | 
| • | The above condition is present for greater than 10 seconds. | 
DTC P0520 is type C DTC.
DTC P0520 is type C DTC.
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 value, test the ground circuit for an open/high resistance. | 
| ⇒ | If not the specified value, test the signal circuit terminal 1 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.
Control Module References for the ECM replacement, setup, and programming