P0523
DTC P0521, P0522, or P0523
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC P0522
- Engine Oil Pressure Sensor Circuit Low Voltage.
DTC P0523
- Engine Oil Pressure Sensor Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The engine oil pressure sensor changes voltage based on the engine oil pressure. The engine oil pressure sensor is a 3-wire sensor comprising of the signal circuit, the low reference circuit and the 5 V reference circuit. The engine control module (ECM) supplies 5 V to the engine oil pressure sensor via the 5 V reference circuit and provides ground via the low reference circuit. The ECM monitors the signal circuit of the engine oil pressure sensor to determine if the engine oil pressure sensor voltage is within the normal operating range of approximately 1-4 V. When the engine oil pressure is high, the engine oil pressure sensor voltage is high and the ECM senses a high signal voltage. When the engine oil pressure is low, the engine oil pressure sensor voltage is low and the ECM senses a low signal voltage. The ECM sends the engine oil pressure information to the instrument cluster via serial data. The instrument cluster will illuminate or display the engine oil pressure indicator when the engine oil pressure is low.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
P0522
* The ECM detects that the engine oil pressure sensor signal circuit is less than 0.2 V.
* The above condition is present for greater than 10 seconds.
P0523
* The ECM detects that the engine oil pressure sensor signal circuit is greater than 4.8 V.
* The above condition is present for greater than 10 seconds.
Action Taken When the DTC Sets
* 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 instrument cluster illuminates the engine oil pressure indicator.
Conditions for Clearing the DTC
* 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.
Reference Information
Schematic Reference
Instrument Cluster Schematics Instrument Cluster Schematics
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
* Indicator/Warning Message Description and Operation Indicator/Warning Message
* Instrument Cluster Description and Operation Instrument Cluster
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
With UDD
1. Ignition ON.
2. Verify the engine oil pressure indicator turns on & off when commanding the All Indicators ON and OFF with a scan tool.
• If the engine oil pressure indicator does not turn on and off.
Replace the P16 Instrument Cluster.
• If the engine oil pressure indicator turns on and off
3. Verify the scan tool Engine Oil Pressure Switch parameter is Low.
• If not Low
Refer to Circuit/System Testing.
• If Low
4. Engine running.
5. Verify the scan tool Engine Oil Pressure Switch parameter is OK.
• If not OK
Refer to Circuit/System Testing.
• If OK
6. All OK.
With UDV
1. Ignition ON.
2. Verify the scan tool Engine Oil Pressure Switch parameter is Low.
• If not Low
Refer to Circuit/System Testing.
• If Low
3. Engine running.
4. Verify the scan tool Engine Oil Pressure Switch parameter is OK.
• If not OK
Refer to Circuit/System Testing.
• If OK
5. All OK.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B37B Engine Oil Pressure Sensor. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the low reference circuit terminal 2 and ground.
• If 10 ohms or greater
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If less than 10 ohms
3. Ignition ON.
4. Test for 4.8-5.2 V between the 5 V reference circuit terminal 3 and ground.
• If less than 4.8 V
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the 5 V reference circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the 5 V reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If greater than 5.2 V
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the 5 V reference circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 Engine Control Module.
• If between 4.8-5.2 V
5. Verify the scan tool Engine Oil Pressure Switch parameter is Low.
• If not Low
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit terminal 1 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K20 Engine Control Module.
• If Low
6. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the 5 V reference circuit terminal 3.
7. Verify the scan tool Engine Oil Pressure Switch parameter is OK.
• If not OK
1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
2. Test for infinite resistance between the signal circuit terminal 1 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K20 Engine Control Module.
• If OK
8. Test or replace the B37B Engine Oil Pressure Sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
Control Module References Control Module References for instrument cluster or engine control module replacement, programming, and setup