C1550

DTC C1550

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 Descriptor
DTC C1550 36
- ECU Failure EEPROM failure

DTC C1550 37
- ECU Failure watchdog/safety failure

DTC C1550 38
- ECU Failure supervision software failure

DTC C1550 39
- ECU Failure internal electronic failure

DTC C1550 3A
- ECU Failure incorrect component installed

Circuit/System Description

Conditions for Running the DTC
DTC C1550 38

Engine starting
DTC C1550 36

Engine running
DTC C1550 39

* Engine starting
* Engine running

Conditions for Setting the DTC
DTC C1550 36, 38, 39

* Control unit software/hardware failure.
* Above condition must be fulfilled for at least 0 seconds.

Action Taken When the DTC Sets
DTC C1550 36

No steering boost function
DTC C1550 38

The system function is not affected.
DTC C1550 39

* The steering boost is switched off.
* The system function is not affected.

Conditions for Clearing the DTC

A history DTC will clear after 60 consecutive malfunction-free ignition cycles.

Reference Information
Schematic Reference

Power Steering Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Power Steering System Description and Operation (TRW) (Description and Operation)
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)

Circuit/System Verification

1. Verify that DTC C1550 is not set.

• If the DTC is set, reprogram the PSCM. If the DTC resets, replace the PSCM.

Repair Instructions

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