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 C0274 54: Isolation Valve High Temperature
DTC C0275 54: Dump Valve High Temperature
DTC C0280 54: Stability System Active Too Long

### Circuit/System Description

The solenoid valves are integral parts of the brake pressure modulator valve assembly. The brake pressure modulator valve assembly contains an isolation solenoid valve and a dump solenoid valve for each wheel and a traction control/stability control supply solenoid valve and isolation solenoid valve for each brake circuit. The solenoid valves are not engaged during normal system operation. When the ABS, traction control or stability control operation is required the electronic brake control module (EBCM) turns the required solenoid valves ON.

### Conditions for Running the DTC

Ignition ON

### Conditions for Setting the DTC

Calculated solenoid valve temperature is greater than threshold.

### Action Taken When the DTC Sets

#### C0274 54 or C0275 54

• | The EBCM disables the ABS, traction control, stability control and hill start assist for the duration of the ignition cycle.

• | The ABS indicator turns ON.

• | The traction control/stability control-active indicator turns ON.

#### C0280 54

• | The EBCM disables the stability control and hill start assist for the duration of the ignition cycle.

• | The traction control/stability control-active indicator turns ON.

### Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

### Diagnostic Aids

DTCs can set because of extended operation of ABS, traction control or stability control.

### 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

Ignition ON, observe the scan tool Inlet, Outlet, Isolation, and Prime Solenoid Valve Feedback parameters. The readings should be Inactive.

### Circuit/System Testing

1. Ignition ON, verify that DTC C0187, C0196, C019B, or C0710 is not set as a present DTC.

⇒ | If any listed DTC is present, refer to Diagnostic Trouble Code (DTC) List - Vehicle to diagnose that DTC prior to this diagnostic.

2. Ignition OFF, let the hydraulic modulator cool down to ambient temperature.
3. Ignition ON, verify that DTC C0274 54, C0275 54, or C0280 54 is not set as a present DTC.

⇒ | If any listed DTC is present, replace the K17 Electronic Brake Control Module (EBCM) and verify DTC does not reset. If the DTC resets replace the brake pressure modulator valve assembly.

### Repair Instructions

• | Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Electronic Brake Control Module Replacement

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