Diagnostic Instructions
| • | 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. |
DTC Descriptor
DTC P0520: Engine Oil Pressure (EOP) Switch Circuit MalfunctionDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Signal | 1 | P0520 | 1 | -- |
Ground | -- | P0520 | -- | -- |
1. Engine Oil Pressure Indicator Malfunction | ||||
Typical Scan Tool Data
Circuit | Short to Ground | Open | Short to Voltage |
|---|---|---|---|
Operating Conditions: Engine Running Parameter Normal Range: OK | |||
Signal | Low | OK | OK |
Ground | -- | OK | -- |
Circuit/System Description
The engine oil pressure 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 engine oil pressure switch opens and the ECM should detect a high signal voltage input. When the oil pressure is low, the ECM sends a message via High Speed CAN-Bus to the body control module (BCM). The BCM then sends a message via Low Speed CAN-Bus to the instrument cluster requesting the engine oil pressure indicator turned ON.
Conditions for Running the DTC
The engine is running
Conditions for Setting the DTC
| • | The ECM detects that the engine oil pressure switch signal circuit is pulled low. |
| • | The above condition is present for greater than 10 seconds. |
Action Taken When the DTC Sets
The instrument cluster illuminates the service vehicle soon indicator and the oil pressure low indicator.
Conditions for Clearing the DTC
The DTC becomes history when the conditions for setting the DTC are no longer present.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the scan tool Engine Oil Pressure Switch parameter with the ignition switch turned ON and the engine not running the reading should be Low, with the engine running the reading should be OK.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the B37 Engine Oil Pressure Switch.
- Ignition ON, verify the scan tool Engine Oil Pressure Switch parameter is OK.
- Install a 3 A fused jumper wire between the signal circuit terminal A and ground. Verify the scan tool Engine Oil Pressure Switch parameter is Low.
- If all circuits test normal, test or replace the B37 Engine Oil Pressure Switch.
| ⇒ | If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the K20 Engine Control Module (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 K20 Engine Control Module (ECM). |
Component Testing
Static Test
- Ignition OFF, disconnect the harness connector at the B37 Engine Oil Pressure Switch.
- Test for infinite resistance between the signal terminal A and ground with the switch in the open position.
- Test for less than 5 Ω between the signal terminal A and ground with the switch in the closed position.
| ⇒ | If not the specified value, replace the B37 Engine Oil Pressure Switch. |
| ⇒ | If greater than the specified range, replace the B37 Engine Oil Pressure Switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Link x Engine Oil Pressure Switch Replacement for LTD. |
| • | Link x Engine Oil Pressure Switch Replacement for LE5. |
| • | Control Module References for ECM replacement, setup, and programming. |
