C0800

DTC C0800

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 Descriptors
DTC C0800 03
- Device Power Circuit Below Threshold - PSCM 12V

DTC C0800 07
- Device Power Circuit Above Threshold - PSCM 12V

Diagnostic Fault Information









Circuit/System Description

The power steering control module (PSCM) monitors the 12V 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 PSCM monitors the system voltage. If the PSCM detects a 12V 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 12V system voltage is less than 10.5 volts.
* During the system operation, the 12V system voltage is less than 9 volts.

C0800 07
* Ignition is in RUN.
* The system voltage is greater than 18.5 volts.

Action Taken When the DTC Sets

* The driver information center (DIC) displays the SERVICE POWER STEERING warning message.
* The PSCM disables steering assist.

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 DC Power Conversion Test (DC Power Conversion Test).
* 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. Refer to DC Power Conversion Test (DC Power Conversion Test).
* Possible causes of this DTC are overcharging or jump starting.

Reference Information
Schematic Reference

* Power Steering Schematics (Electrical Diagrams)
* Starting and Charging Schematics (Electrical Diagrams)
* Power Distribution Schematics (Power Distribution Schematics)
* Ground Distribution Schematics (Ground Distribution Schematics)

Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

* Power Steering System Description and Operation (Hydraulic Power Steering) (Power Steering System Description and Operation (Hydraulic Power Steering))Power Steering System Description and Operation (EPS) (Power Steering System Description and Operation (EPS))
* 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 12V 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 PSCM Battery Voltage parameter. The reading should be between 12.60 and 15.00 volts.

Circuit/System Testing

Danger: Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.


The High Voltage Disabling procedure will perform the following tasks:


* Identify how to disable high voltage.

* Identify how to test for the presence of high voltage.

* Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.


Failure to follow the procedures exactly as written may result in serious injury or death.


1. Ignition OFF, disconnect the harness connectors at the PSCM.
2. Verify that a test lamp illuminates between the 12V B+ circuit terminal 5 X2 and ground.

• If the test lamp does not illuminate, test the 12V B+ circuit for a short to ground or an open/high resistance.

3. If all circuits test normal, replace the PSCM.

Repair Instructions

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

Control Module References (Programming and Relearning) for PSCM replacement, setup, and programming.