C0800

DTC C0800

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 Descriptors
DTC C0800 03
- Device Power Circuit Voltage Below Threshold


DTC C0800 07
- Device Power Circuit Voltage Above Threshold




Diagnostic Fault Information






Circuit/System Description

The electronic brake control module (EBCM) monitors the ignition voltage level available for system operation. A low voltage condition prevents the system from operating properly, 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 voltages supplied to the control module is in the range of 7-26 volts.
* The ignition is ON.
* The engine is running.



Conditions for Setting the DTC

C0800 03

This DTC will be set if the system voltage to EBCM is less than 9 volts for 100 msec.

C0800 07

This DTC will be set if the system voltage is greater than 16 volts for 100 msec.


Action Taken When the DTC Sets

* Antilock Brake System (ABS) and Traction Control System (TCS) are disabled for the duration of the ignition cycle.
* The ABS and TCS indicators illuminates on the IPC.
* The DIC displays the Service Stability System message, if equipped.



Conditions for Clearing the DTC

The DTC clears when the system voltage returns to a normal range.


Diagnostic Aids

* A high or low voltage DTC set in multiple control modules indicates a concern in the charging system.
* A possible cause of this DTC could be overcharging with a battery charger or jump starting.
* A high or low voltage value in multiple control modules indicates a concern in the charging system.



Reference Information
Schematic Reference

Control Module References (Programming and Relearning)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Charging System 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 measure and record the voltage at the battery terminals. Verify that the battery voltage is 12.6-15.5 volts.

• If the battery voltage is not within the specified range, refer to Charging System Test (Charging System Test)

2. Engine running, observe the scan tool EBCM System Voltage parameter.
3. Verify the scan tool parameter displays a value that is within 2 volts of the battery terminal voltage.



Circuit/System Testing

1. Ignition OFF. Disconnect the harness connectors at the EBCM.
2. Verify there is less than 3 ohms between the ground circuit terminals 13 and 26 to ground.

• If greater than the specified value, test the ground circuits for an open/high resistance.

3. Ignition ON, verify a test lamp illuminates between the ignition voltage circuit terminal 20 and ground.

• If the test lamp did not illuminate , test the ignition voltage circuit for a short to ground or an open/high resistance.

4. Ignition ON, verify a test lamp illuminates between the battery positive voltage circuits terminals 1-14-44 and ground.

• If the test lamp did not illuminate , test the affected battery positive voltage circuit for a short to ground or an open/high resistance.

5. If all the circuits test normal, 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