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 00: Device Voltage High - EBCM

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
B+ | C0899 00 | C0899 00 | -- | --
Ground | -- | C0899 00 | -- | --

### Typical Scan Tool Data

#### Battery Voltage Signal - EBCM

Circuit | Short to Ground | Open | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Ignition ON, Engine OFF. Parameter Normal Value: 12.60 Volts.
B+ | 0.00 Volts* | 0.00 Volts* | --
*The scan tool will not communicate with the EBCM if the battery voltage is less than 7 volts.

### Circuit/System Description

The electronic brake control module (EBCM) monitors the battery voltage level available for system operation. A high voltage condition prevents the system from operating properly. If the EBCM detects high battery voltage, DTC C0900 00 will set.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

The EBCM detects that the battery voltage is greater than 18 volts.

### Action Taken When the DTC Sets

• | The antilock brake system (ABS), electronic brake force distribution (EBD), traction control system (TCS), and vehicle stability enhancement system (VSES) are disabled.

• | The ABS, BRAKE, and vehicle dynamics caution (VDC) indicators turn ON.

• | The driver information center (DIC) displays the ALL WHEEL DRIVE OFF message, if equipped.

• | The ABS pump motor turns ON if the voltage is greater than 28 volts.

### Conditions for Clearing the DTC

• | The DTC will pass when the condition for setting the DTC is no longer present, and the ignition is cycled.

• | The EBCM clears a history DTC when the DTC does not fail in 100 consecutive ignition cycles.

• | The indicators and DIC message turn OFF when the battery voltage is less than 18 volts.

### Diagnostic Aids

• | This DTC could be set by overcharging with a battery charger or jump starting.

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

### Reference Information

#### Schematic Reference

Antilock Brake System Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

• | ABS Description and Operation

• | Charging System 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

1. Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 volts.

⇒ | If not within the specified range, refer to Charging System Test.

2. Observe the scan tool EBCM Battery Voltage Signal parameter. The reading should be between 12.6 and 15.0 volts.

⇒ | If greater than the specified range, replace the EBCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup and programming.