PSCM

DTC C0900 (PSCM)

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 Descriptor

DTC C0900 00
- Device Voltage High

Diagnostic Fault Information






Circuit/System Description

The power steering control module (PSCM) monitors the amount of battery voltage available to it. If the voltage is too high, then the PSCM sets DTC C0900 00 and disables itself in order to protect itself against high voltage damage.

Conditions for Running the DTC

Ignition is ON.

Conditions for Setting the DTC

Power steering system voltage is greater than 16 volts for 1 second.

Action Taken When the DTC Sets

* DTC C0900 00 is stored in memory.
* The DIC displays the POWER STEERING warning message.
* The PSCM is disabled.
* No steering assist is provided.

Conditions for Clearing the DTC

* A current DTC will clear when the power steering system voltage returns to less than 16 volts.
* A history DTC will clear after 100 consecutive ignition cycles from when power steering system voltage is less than 16 volts.

Diagnostic Aids

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

Circuit/System Verification

1. If the DTC is history, or if other modules have also set high voltage DTCs, refer to Charging System Test. Charging System Test
2. Start the engine. Measure and record the voltage at the battery terminals. Observe the scan tool Battery Voltage Signal parameter in the PSCM data list. The voltages should not differ by greater than 1 volt.

• If the difference is greater than 1 volt, replace the PSCM.

Repair Instructions

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