For 1990-2009 cars

### 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 C0131 00: ABS Pressure Circuit
DTC C0131 4B: ABS Pressure Circuit Calibration Not Learned
DTC C0131 5A: ABS Pressure Circuit Plausibility Failure

### Circuit/System Description

The electronic brake control module (EBCM) monitors the inputs of the internal brake pressure sensor and the internal temperature sensor for more accurate control during a vehicle stability enhancement system (VSES) event.

### Conditions for Running the DTC

Ignition ON.

### Conditions for Setting the DTC

#### C0131 00

The EBCM detects an internal pressure sensor fault.

#### C0131 4B

The pressure sensor calibration not learned

#### C0131 5A

The EBCM detects the readings between the internal brake pressure sensor and the internal temperature sensor do not correlate.

### Action Taken When the DTC Sets

• | The EBCM disables the antilock brake system (ABS), traction control system (TCS) and vehicle stability enhancement system (VSES) for the duration of the ignition cycle.

• | The EBCM sends a serial data message to illuminate the appropriate warning indicator/message.

### Conditions for Clearing the DTC

• | The condition for setting the DTC is no longer present.

• | The EBCM clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.

### Reference Information

#### Schematic Reference

Antilock Brake System Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

ABS 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

#### C0131 4B or 5A:

Verify DTC C0131 4B or 5A is not set.

⇒ | If the DTC is set, perform the Sensor Cluster Calibration and verify the DTC does not reset. If the DTC resets replace the EBCM and BPMV.

#### C0131 00:

Verify DTC C0131 00 is not set.

⇒ | If the DTC is set, replace the brake pressure modulator valve (BPMV) and verify the DTC does not reset. If the DTC resets replace the EBCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Brake Pressure Modulator Valve Replacement

• | Control Module References for EBCM replacement, setup, and programming