C1529

DTC C1529

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 C1527 0B
- Motor Circuit High Current Current Above Threshold

DTC C1527 01
- Motor Circuit High Current Short to Battery

DTC C1529 00
- Motor Circuit Low Current Malfunction




Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.






Circuit/System Description

The power steering control module (PSCM) monitors the motor amperage to ensure that the amperage stays within proper range. Damage to components and incorrect data may occur when the amperage is out of range.


Conditions for Running the DTC


* Engine Running or Engine Starting (see below)
* Power steering pump motor amperage is 55-65 Amps with the steering wheel turned and held full right or left..



Conditions for Setting the DTC
DTC C1527 0B, 01

The actual motor current is greater than 75 Amps for at least 1.0 second during igniton ON and engine starting.
DTC C1529 00

The actual motor current is less than 11 amps during engine starting.


Action Taken When the DTC Sets
DTC C1527 0B, 01

Steering boost is switched OFF.
DTC C1529 00

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) (Power Steering System Description and Operation (TRW))Power Steering System Description and Operation (ZF) (Power Steering System Description and Operation (ZF))
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. Engine running, accessories OFF, measure and record the actual motor current. Power steering pump motor amperage is 55-65 Amps with the steering wheel turned and held full right or left.

• If not within the specified range, refer to Charging System Test (Charging System Test) .

2. Observe the scan tool Electro-hydraulic power steering ECU Battery Voltage. The reading should be between 9.0 and 16.0 volts.



Circuit/System Testing
Actual Pump Motor Current

1. Ignition OFF, Wait 3 seconds, Ignition ON, All accessories OFF with a scan tool verify pump motor amperage to be 0 Amps
2. Ignition ON, Engine ON, All accessories OFF, Battery Voltage range to be between 4-9 Amps.
3. Turn steering wheel right until stop, turn slightly further and hold firmly in this position. The amperage range should be between 55-65 Amps.
4. Turn steering wheel left until stop, turn slightly further and hold firmly in this position. The amperage range should be between 55-65 Amps.

• If the amperage is not within the specified range, replace the power steering control module.


• If the amperage is within the specified range, refer to desired pump speed.


Desired Pump Speed

1. Ignition OFF, Wait 3 seconds, Ignition ON, All accessories OFF with a scan tool verify engine RPM is 0.
2. Engine Running, with a scan tool verify engine RPM to be 2660.

• If the RPM is not specified value, replace the power steering control module.


• If the RPM is the specified value, refer to the Actual Pump Speed.


Actual Pump Speed

1. Ignition OFF, Wait 3 seconds, Ignition ON, All accessories OFF, with a scan tool verify the engine RPM to be 0.
2. Engine Running, with a scan tool verify engine RPM range to be 2655-2665 RPM.

• If the RPM is not within the specified range, replace the power steering control module.




Repair Instructions

Important: For any module replacement a set procedure needs to be followed. A "Reset" may need to be performed from the PROGRAMMING menu of the current system with the scan tool BEFORE replacing the module.



* Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.
* Power Steering Pump Replacement (TRW) (Service and Repair)Power Steering Pump Replacement (ZF) (Service and Repair)
* Power Steering Pump Wiring Harness Replacement (Service and Repair)