C0900

DTC C0900 or C12E2

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (with HP2) (Initial Inspection and Diagnostic Overview)Diagnostic System Check - Vehicle (without HP2) (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 Descriptors
DTC C0900 00
- Device Voltage High -EBCM 12V

DTC C0900 07
- Device Voltage High -EBCM 12V

DTC C12E2 00
- Device Voltage High -EBCM 12V

Diagnostic Fault Information





Typical Scan Tool Data





Circuit/System Description

The electronic brake control module (EBCM) monitors the 12 V battery positive (B+) 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 12 V battery voltage from the solenoid valves and pump motor, and DTC C0900 sets.

Conditions for Running the DTC

Ignition is ON.

Conditions for Setting the DTC

The 12 V battery voltage is greater than 16 volts for 100 msec.

Action Taken When the DTC Sets

* The traction control system (TCS) and vehicle stability enhancement system (VSES) are disabled for the duration of the ignition cycle.
* The antilock brake system (ABS) is disabled if ignition voltage exceeds 19.5 V.
* The stability system off and traction control off indicators turn ON.
* The ABS indicator turns ON if voltage exceeds 19.5 V.

Conditions for Clearing the DTC

* The DTC will pass when the battery voltage is less than 15.5 V for 100 msec.
* The EBCM automatically clears a history DTC when a current DTC is not detected in 100 consecutive drive cycles.
* The indicators and DIC messages turn OFF when the DTC is cleared, or on the next malfunction-free ignition cycle.

Diagnostic Aids

* This DTC could be set by overcharging with a battery charger.
* 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 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 scan tool information

Circuit/System Verification

1. Engine running, accessories OFF, measure and record the battery voltage at the 12 V battery terminals. The voltage should be between 12.6-15.0 V.

• If not within the specified range, refer to Charging System Test (Charging System Test).

2. Observe the scan tool EBCM Battery Voltage parameter. The reading should be between 12.6-15.0 Volts.

• If greater than 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.