C0845

DTC C0845

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 C0845 01
- Device Ignition 1 Circuit Short to B+

DTC C0845 06
- Device Ignition 1 Circuit Short to Ground or Open

Diagnostic Fault Information





Circuit/System Description

The body control module (BCM) contains the 2-amp EPS fuse. When the ignition is ON the BCM supplies voltage to the ignition circuit to wake up the power steering control module (PSCM). The PSCM receives a serial data message from the BCM to determine the position of the ignition switch. When a power mode message is received, the PSCM monitors the ignition voltage circuit to detect if a short to voltage, short to ground, or an open exists.

Conditions for Running the DTC

Ignition ON.

Conditions for Setting the DTC

The power mode message and the state of the PSCM's ignition circuit do not agree, or the PSCM's ignition circuit is shorted to voltage, ground or open

Action Taken When the DTC Sets

* The driver information center (DIC) displays POWER STEERING, SERVICE TRACTION, and SERVICE ESC warning messages.
* Stability Control indicator illuminates,
* Security indicator illuminates.

Conditions for Clearing the DTC

* When the condition is no longer present.
* A history DTC will clear after 100 consecutive malfunction-free ignition cycles.

Reference Information
Schematic Reference

Power Steering Schematics (Electrical Diagrams)
Description and Operation

Power Steering System Description and Operation (Description and Operation)
Connector End View Reference

Component Connector End Views (Connector Views)
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. Verify that DTC U1300 or U1301 is not set.

• If either of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle (Diagnostic Trouble Code Descriptions).

2. Ignition ON, observe the scan tool PSCM Ignition Voltage parameter. The reading should be B+.

Circuit/System Testing

1. Ignition OFF, disconnect the X2 harness connector at the PSCM.
2. Verify that a test lamp does not illuminate between the ignition circuit terminal 6 and ground.

• If the test lamp illuminates, test the ignition circuit for a short to voltage. If the circuit tests normal, replace the BCM.

3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 6 and ground.

• If the test lamp does not illuminate, test the ignition circuit for a short to ground or and open/high resistance. If the circuit tests normal, replace the BCM.

4. If all circuits test normal, replace the steering column.

Repair Instructions

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

* Steering Column Replacement (Steering Column Replacement)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming