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 C0899 00: Device Voltage Low - EBCM
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 | 12.60 Volts

### Circuit/System Description

The electronic brake control module (EBCM) monitors the battery voltage available for system operation. A high or low voltage condition prevents the system from operating properly. If the EBCM detects battery voltage out of range, DTC C0899 or DTC C0900 will set.

### Conditions for Running the DTC

• | The ignition is ON.

• | The vehicle speed is greater than 6 km/h (3.7 mph).

### Conditions for Setting the DTC

#### C0899

The EBCM detects that the battery voltage is less than 9.3 volts.

#### C0900

The EBCM detects that the battery voltage is greater than 16.8 volts.

### Action Taken When the DTC Sets

#### C0899

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

• | The dynamic rear proportioning (DRP) is disabled, if the battery voltage is less than 6.9 volts.

• | The ABS and traction control indicators turn ON.

• | The BRAKE indicator turns ON, if the battery voltage is less than 6.9 volts.

• | The driver information center (DIC) displays the TRACTION CONTROL OFF message 1 time.

• | The DIC displays the SERVICE STABILITRAK and SERVICE TRACTION CONTROL messages.

#### C0900

• | The ABS, DRP, TCS, and VSES are disabled.

• | The ABS, BRAKE, and traction control indicators turn ON.

• | The DIC displays the TRACTION CONTROL OFF message 1 time.

• | The DIC displays the SERVICE STABILITRAK and SERVICE TRACTION CONTROL messages.

### Conditions for Clearing the DTC

• | The DTC will pass when 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.

• | The ABS, BRAKE, and traction control indicators turn OFF when the DTC passes, or when the battery voltage is greater than 9.5 volts.

### Diagnostic Aids

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

• | DTC C0900 could be set by overcharging with a battery charger or jump starting.

• | The ABS, BRAKE, and traction control indicators may turn ON without any DTCs set, if the EBCM detects that the battery voltage is less than 9.5 volts, and the vehicle speed is less than 6 km/h (3.7 mph).

### 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

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.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Ignition OFF and scan tool disconnected, open and close the driver door, and wait 1 minute. Test for less than 5 ohms between the ground circuit terminals listed below and ground.

• | Terminal 13

• | Terminal 38

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Verify that a test lamp illuminates between the B+ circuit terminals listed below and ground.

• | Terminal 1

• | Terminal 25

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. If all circuits test normal, replace the EBCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for EBCM replacement, setup and programming.