C0800

DTC C0800

Diagnostic Instructions

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

DTC Descriptors

DTC C0800 03
- Voltage Below Threshold

DTC C0800 07
- Voltage Above Threshold

Diagnostic Fault Information






Circuit/System Description

The electronic brake control module (EBCM) monitors the system voltage to make sure that the voltage stays within the proper range. Damage to components, and incorrect data input can occur when the voltage is out of range. The EBCM monitors the system voltage over an extended length of time. If the EBCM detects a system voltage outside an expected range, DTC C0800 will set.

Conditions for Running the DTC

C0800 03

* Ignition is in RUN.
* The system relay is commanded ON.

C0800 07

* Ignition is in RUN.
* The vehicle speed is greater than 8 km/h (5 mph).

Conditions for Setting the DTC

C0800 03

* During initialization or when the system is inactive, the system voltage is less than 10.5 volts.
* During the system operation, the system voltage is less than 9 volts.

C0800 07

* Ignition is in RUN.
* The system voltage is greater than 17 volts.

Action Taken When the DTC Sets

* The EBCM disables the ABS and dynamic rear proportion (DRP) is degraded when the code is current.
* The ABS indicator turns ON.

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

C0800 03

* A low voltage DTC in multiple modules indicates a concern in the charging system. Refer to Diagnostic System Check - Vehicle. Initial Inspection and Diagnostic Overview
* Possible causes of this DTC are the following conditions:

- A charging system malfunction
- An excessive battery draw
- A weak battery
- A poor system ground
- An open or high resistance in a circuit
- An internal module malfunction

C0800 07

* Test the charging system.
* Possible causes of this DTC are overcharging or jump starting.

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 12.6 and 15.0 volts.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the EBCM.
2. Ignition OFF, test for less than 5 ohms between the ground circuit terminal 26 and ground.

• 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 14
* Terminal 20

• 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 tests normal, replace the EBCM.

Repair Instructions

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