P0523
Engine Oil Pressure Indicator or Gauge Malfunction - DTC P0521-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 P0521
- Engine Oil Pressure Sensor Performance
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 is a 3-wire sensor comprising of a signal circuit, low reference circuit and the 5-volt reference circuit. The engine control module (ECM) supplies 5 volts to the sensor via the 5-volt reference circuit and provides ground via the low reference circuit. The ECM monitors the signal circuit to determine the sensor voltage is within the normal operating range of approximately 1-4 volts. When the engine oil pressure is high, the sensor voltage is high and the ECM senses a high signal voltage. When the engine oil pressure is low, the sensor voltage is low and the ECM senses a low signal voltage. The ECM sends the engine oil pressure information via serial data to the body control module (BCM). The BCM then sends the engine oil pressure information to the instrument panel cluster (IPC) via serial data.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
P0521
* The engine oil pressure is out of its working range.
* The ECM does not detect a change in the engine oil pressure.
* The above condition is present over a predetermined variance of engine speed.
P0522
* The ECM detects a short to ground in the engine oil pressure signal circuit.
* The above condition is present for greater than 10 seconds.
P0523
* The ECM detects a short to voltage or an open circuit in the engine oil pressure signal circuit.
* 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
Instrument Cluster Schematics Instrument Cluster Schematics
Connector End View Reference
Component Connector End Views Sunshade - Left
Description and Operation
* Instrument Cluster Description and Operation Instrument Cluster
* Indicator/Warning Message Description and Operation Indicator/Warning Message
* Driver Information Center (DIC) Description and Operation Driver Information Center (DIC)
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
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 parameter is Low.
• If not Low
Refer to Circuit/System Testing.
• If Low
4. Engine running.
5. Verify the scan tool Engine Oil Pressure parameter is OK.
• If not OK
Refer to Circuit/System Testing.
• If OK
6. 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 parameter is less than 1 V.
• If 1 V or greater
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 less than 1 V
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 parameter is greater than 4.8 V.
• If 4.8 V or less
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 greater than 4.8 V
8. Test or replace the B37B engine oil pressure sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Engine Oil Pressure Switch Replacement
* Control Module References Control Module References for instrument cluster or ECM replacement, setup, and programming