GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Kodiak C-Series (Conventional) C4/C5 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC P0521, P0522, or P0523

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 Descriptors

DTC P0522: Engine Oil Pressure (EOP) Sensor Circuit Low Voltage.

DTC P0523: Engine Oil Pressure (EOP) Sensor Circuit High Voltage

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Engine Oil Pressure 5-Volt Reference

P0522

1

P0522

P0523

--

Engine Oil Pressure Sensor Signal

P0522

1

P0522

P0523

--

Low Reference

--

1

P0523

--

--

1. Engine Oil Pressure Gage Inaccurate or Inoperative

Circuit Description

The engine oil pressure (EOP) sensor changes resistance based on engine oil pressure. The engine control module (ECM)/powertrain control module (PCM) monitors the signal circuit of the EOP sensor. When the engine oil pressure is high, the sensor resistance is high and the ECM/PCM senses a high signal voltage. When the engine oil pressure is low, the sensor resistance is low and the ECM/PCM senses a low signal voltage. The ECM/PCM sends the engine oil pressure information to the instrument panel cluster (IPC) via the class 2 serial data circuit.

Conditions for Running the DTC
    • The engine is running.
    • DTC P1635, (LMM, and late L18) or DTC P0641, (early L18) is not present.

Conditions for Setting the DTC

P0522

    • The ECM/PCM detects that the EOP sensor signal circuit is less than 0.4 volts.
    • The above condition is present for greater than 9 seconds.

P0523

    • The ECM/PCM detects that the EOP sensor signal circuit is greater than 4.6 volts.
    • The above condition is present for greater than 9 seconds.

Action Taken When the DTC Sets

The ECM/PCM records the operating conditions at the time the diagnostic test fails. The ECM/PCM displays this information in the Failure Records on the scan tool.

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

Connector End View Reference

Component Connector End Views

Description and Operation

Instrument Cluster Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification
  1. Ignition ON, perform the engine oil gage sweep test with the scan tool. Verify that the engine oil pressure gage sweeps from its low to high position.
    2. ⇒If the engine oil pressure gage does not sweep, replace the IPC.
  2. Engine running, observe the scan tool Engine Oil Pressure Sensor parameter. The reading should be between 0.5-4.5 volts.
  3. Verify the engine oil pressure, refer to:
    4. •  Oil Pressure Diagnosis and Testing for the 6.6L engine
    •  Oil Pressure Diagnosis and Testing for the 8.1L engine.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the EOP sensor.
  2. Ignition OFF, test for less than 1 ohm between the low reference circuit terminal 1 and ground.
    3. ⇒If greater than the specified range, test the low reference circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM/PCM.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
    4. ⇒If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the ECM/PCM.
    ⇒If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the ECM/PCM.
  4. Install a 3-amp fused jumper wire between the signal circuit terminal 2 and the low reference circuit terminal 1. Verify the scan tool Engine Oil Pressure Sensor parameter is less than 0.4 volt.
    5. ⇒If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM/PCM.
  5. Install a 3-amp fused jumper wire between the signal circuit terminal 2 and the 5-volt reference circuit terminal 3. Verify the scan tool Engine Oil Pressure Sensor parameter is greater than 4.6 volts.
    6. ⇒If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the ECM/PCM.
  6. If all circuits test normal, test or replace the EOP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Engine Oil Pressure Sensor and/or Switch Replacement for the 6.6L engine
    •  Engine Oil Pressure Sensor and/or Switch Replacement for the 8.1L engine
    •  Control Module References for the ECM/PCM replacement, setup, and programming