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 C0900: Device Voltage High

### Circuit/System Description

The electronic brake control module (EBCM) monitors the battery voltage. If the voltage level is too high, damage may result in the system. When a high voltage condition is detected the EBCM turns OFF the system relay which removes battery voltage from the solenoid valves and pump motor.

### Conditions for Running the DTC

Ignition is ON.

### Conditions for Setting the DTC

The system voltage is greater than 17 volts for 10 msec.

### Action Taken When the DTC Sets

• | ABS disabled if ignition voltage exceeds 17 volts.

• | The Antilock Brake System (ABS) indicator and engine traction (ETS)/ brake warning lamp turns ON if voltage exceeds 17 volts.

### Conditions for Clearing the DTC

• | The condition for 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.

### Diagnostic Aids

Test the charging system. Refer to Battery Inspection/Test and Charging System Test .

### Reference Information

#### Schematic Reference

Antilock Brake System Schematics

#### Connector End View Reference

Antilock Brake System 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

Scan Tool Data List for EBCM

### Circuit/System Testing

1. Measure the voltage at the battery terminals.
2. With scan tool, read the battery voltage in the EBCM data list.

⇒ | If more than 17 volt, test the check the charging system.

3. Go to Battery Inspection/Test and Charging System Test .

### Repair Instructions

Perform the Diagnostic Repair Verification After completing the diagnostic procedure.

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

• | Generator Replacement