C0900

DTC C0900

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptor
DTC C0900 00
- Device Voltage High - EBCM

Diagnostic Fault Information





Typical Scan Tool Data





Circuit/System Description

The electronic brake control module (EBCM) monitors the ignition 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

The ignition is ON.

Conditions for Setting the DTC

The EBCM detects that the battery voltage is greater than 16 volts (w/o HP7) or 17 volts (HP7).

Action Taken When the DTC Sets

* The antilock brake system (ABS) is disabled. (HP7)
* The dynamic rear proportioning (DRP) defaults to hold only. (HP7)
* The ABS and DRP are disabled, if the battery voltage is greater than 19.5 volts. (w/o HP7)
* The vehicle stability enhancement system (VSES) is disabled, if equipped.
* The hydraulic brake assist (HBA) and traction control system (TCS) are disabled. (w/o HP7)
* The TCS is reduced to engine torque reduction only. (HP7)
* The ABS indicator turns ON. (HP7)
* The ABS indicator turns ON, if the battery voltage is greater than 19.5 volts. (w/o HP7)
* The BRAKE and VDC indicators turn ON.
* The driver information center (DIC) displays the ESC OFF message 1 time, if equipped.
* The DIC displays the SERVICE ESC message, if equipped.
* The DIC displays the SERVICE TRACTION message.

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.
* The indicators and DIC messages turn OFF when the DTC passes.

Diagnostic Aids

* A possible cause of this DTC could be 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 (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

* ABS Description and Operation (Description and Operation)
* Charging System Description and Operation (Description and Operation)

Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) 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 (Charging System Test).

2. Observe the scan tool EBCM Battery Voltage Signal parameter. The reading should be between 12.60 and 15.00 volts.

• If not within the specified range, replace the EBCM.

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.