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 C0201 04: Antilock Brake System (ABS) Enable Relay Contact Circuit

### Circuit/System Description

The solenoid relay, located within the electronic brake control module (EBCM), supplies battery voltage to all of the valve solenoids.

### Conditions for Running the DTC

• | Ignition voltage is greater than 9.5 volts.

• | The solenoid relay is commanded ON.

### Conditions for Setting the DTC

One or more of the following conditions exists:

• | The EBCM detects an open in the battery positive voltage circuit to the solenoid valve relay.

• | The EBCM detects a stuck open solenoid valve relay or an open circuit between the solenoid valve relay and solenoid valves.

### Action Taken When the DTC Sets

• | The EBCM disables the ABS/dynamic rear proportion (DRP) for the duration of the ignition cycle.

• | The ABS indicator turns ON.

• | The red brake warning indicator turns ON.

### Conditions for Clearing the DTC

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

• | The EBCM automatically 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

Antilock Brake System Connector End Views

#### Description and Operation Reference

ABS Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Scan Tool Data List for EBCM

### Circuit/System Verification

With the scan tool, access the ABS special functions menu and perform the ABS Motor test. The pump motor should function and no DTCs should be set.

### Circuit/System Testing

Test for an open or a short to ground in the solenoid valve battery positive voltage circuit.

⇒ | If battery positive voltage circuit tests normal, replace the EBCM/BPMV 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