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

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

With the scan tool installed, ignition ON and the engine OFF, observe the Battery Positive Voltage parameter in the EBCM data list. The reading should be between 9-17 volts.

Circuit/System Testing

1. Perform a charging system test and verify that the vehicle battery is fully charged. Refer to Charging System Test. Charging System Test

^ If the battery is not fully charged, refer to Battery Charging.

2. Verify that the DTC is current.

^ If the DTC is history, refer to Charging System Test and Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids. Charging System Test Component Tests and General Diagnostics

3. Ignition ON. Verify that there is 9-17 volts between the battery positive voltage circuits terminals 1 and 32 of the EBCM and the ground circuit terminal 16.

^ If the voltage is not within 9-17 volts, test the battery positive ground circuits and the ground circuit of the EBCM for a high resistance or an open, and repair as necessary.

4. If all circuits test normal, replace the EBCM.

Repair Instructions

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