For 1990-2009 cars

### Diagnostic Instructions

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

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptor

DTC C1525 02: Engine Running Signal Short to Ground
DTC C1525 08: Engine Running Signal Invalid

### Diagnostic Fault Information

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

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Engine Running Signal | C1525 02 | C1525 08 | -- | --

### Circuit/System Description

A short to ground, poor resistance, or short to voltage on the generator turn ON signal or engine running signal circuit between the power steering control module and the underhood fuse block.

### Conditions for Running the DTC

Engine running.

### Conditions for Setting the DTC

Engine running signal detected low for 100 milliseconds.

### Action Taken When the DTC Sets

• | The steering boost is increased step-wise (intermittent condition).

• | The steering boost is decreased step-wise (No signal condition).

### Conditions for Clearing the DTC

The trouble code is deleted after the system was switched on 1 times and there was no fault recognized.

### Diagnostic Aids

Confirm the vehicle is or is not equipped with a rear electrical center configuration. Verify scan tool is correctly identifying REC equipped status on the vehicle.

### Reference Information

#### Schematic Reference

Power Steering Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Power Steering System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

Ignition ON, Engine Running, with a scan tool observe the Electronic Hydraulic Power Steering (EHPS) Engine Running Signal Inactive/Active scan tool data.

### Circuit/System Testing

1. Ignition OFF, disconnect the X2 harness connector at the power steering control module.
2. Ignition ON, Engine Running, verify a test lamp illuminates between the signal circuit terminal 5 and ground.

⇒ | If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance. if the circuit tests normal, test or replace the underhood junction block.

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

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Important: For any module replacement a set procedure needs to be followed. A "Reset" needs to be performed from the PROGRAMMING menu of the current system with the Tech 2 BEFORE replacing the module.

• | Power Steering Pump Replacement

• | Power Steering Pump Wiring Harness Replacement

• | Underhood Electrical Center or Junction Block Replacement