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 P0575 00: Cruise Control Switch Signal Circuit

### Circuit/System Description

When a cruise control function switch is activated, the body control module (BCM) detects a predetermined voltage signal. The BCM sends a GMLAN serial data message to the engine control module (ECM) indicating the function that has been requested.

### Conditions for Running the DTC

The ignition is ON.

### Conditions for Setting the DTC

• | The ECM receives an invalid cruise control switch status GMLAN serial data message from the BCM.

• | This diagnostic runs continuously.

### Action Taken When the DTC Sets

• | The Cruise Control System is disabled.

• | The ECM stores the DTC information into memory when the diagnostic runs and fails.

• | The malfunction indicator lamp (MIL) will not illuminate.

• | The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records.

• | All cruise control function switches are set to OFF.

### Conditions for Clearing the DTC

• | The DTC becomes history when the conditions for setting the DTC are no longer present.

• | The history DTC clears after 40 consecutive warm-up cycles.

### Diagnostic Aids

• | This DTC may be stored as a history DTC without affecting the operation of the BCM. If stored only as a history DTC and not retrieved as a current DTC, do not replace the BCM or ECM.

• | If this DTC is retrieved as both a current and history DTC, replace the BCM.

### Reference Information

#### Schematic Reference

Cruise Control Schematics

#### Connector End View Reference

Cruise Control Connector End Views

#### Description and Operation

Cruise Control Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

• | Scan Tool Data List

• | Scan Tool Data Definitions

### Circuit/System Verification

Ignition ON, observe the scan tool Cruise Control Switch parameter while pressing the cruise control switch ON and OFF. The reading should change between ON and OFF.

⇒ | If the parameter does not switch between ON and OFF, replace the BCM.

### Circuit/System Testing

Ignition ON, verify that DTC P0575 is stored in the ECM.

⇒ | If the DTC is stored as a current DTC, replace the ECM.

⇒ | If the DTC is stored only as a history DTC, refer to Diagnostic Aids. Do not replace the ECM or BCM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for BCM or ECM replacement, setup, and programming.