For 1990-2009 cars

### Diagnostic Information

• | 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 C0901: Device 2 Voltage Low

### Circuit/System Description

The electronic brake control module (EBCM) monitors the ignition 1 voltage (IGN1) level available for system operation. A low voltage condition prevents the system from operating properly.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

• | Ignition 1 (IGN1) voltage to EBCM is less than 6.5 volts for 7 seconds.

• | Vehicle speed is greater than 3 km/h (2 mph).

### Action Taken When the DTC Sets

Brake Warning indicator turns ON.

### Conditions for Clearing the DTC

• | The condition for the DTC is no longer present and the DTC is cleared with a scan tool.

• | 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

#### Electrical Information Reference

• | Charging System Test

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Scan Tool Data List for EBCM

### Diagnostic Aids

• | A possible cause of this DTC could be overcharging with a battery charger or jump starting.

• | A high voltage value in multiple modules indicates a concern in the charging system.

### Circuit/System Verification

1. If the DTC is history, refer to Charging System Test .
2. Start the engine. Record the voltage at the battery terminals. Observe the battery voltage signal parameter in the EBCM data list. Voltages should not differ by more than 1 volt.

⇒ | If more than 1 volt, replace the EBCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup, and programming