Antilock Brake System

DTC C0900

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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 (Solstice) (Battery Inspection/Test)Battery Inspection/Test (SKY) (Battery Inspection/Test) and Charging System Test (Solstice) (Charging System Test)Charging System Test (SKY) (Charging System Test) .


Reference Information
Schematic Reference

Antilock Brake System Schematics ([1][2]Antilock Brakes / Traction Control Systems)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

ABS Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) 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 (Solstice) (Battery Inspection/Test)Battery Inspection/Test (SKY) (Battery Inspection/Test) and Charging System Test (Solstice) (Charging System Test)Charging System Test (SKY) (Charging System Test) .



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Control Module References (Programming and Relearning) for EBCM replacement, setup, and programming
* Generator Replacement (Service and Repair)