P0568

DTC P0568

DTC Descriptor

DTC P0568 00
- Cruise Control Set Switch Circuit

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview






Circuit/System Description

The cruise control switch is an input to the engine control module (ECM), while the cruise cancel switch is an input to the body control module (BCM). The ECM monitors the cruise control on/off, set/coast, and the resume/accelerate switch signal circuits in order to detect when a cruise control function switch has been activated. The ECM detects a predetermined voltage signal when a cruise control function switch is applied, with each switch having a different voltage value.

The BCM monitors the cruise cancel switch in order to detect when the cancel switch has been activated. The BCM sends a class 2 message to the ECM regarding the status of the cruise cancel switch.

Conditions for Running the DTC

* The ignition is ON.
* The cruise control switch is ON.

Conditions for Setting the DTC

The ECM detects that the resume/accel switch is applied for longer than 90 seconds.

Action Taken When the DTC Sets

* 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.
* The cruise control system is disabled.

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 malfunction-free warm-up cycles.
* The ECM receives a clear code command from the scan tool.

Diagnostic Aids

* Ensure that the resume/accel switch is not stuck or sticking in the engaged position.
* For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids. Component Tests and General Diagnostics

Circuit/System Testing

1. Ignition ON, verify that the Cruise Resume/Accel. Switch parameter reads Active or Invalid.

• If the parameter reads Inactive, go to Diagnostic Aids.

2. Ignition OFF, disconnect the harness connector at the cruise control switch.
3. Ignition ON, cruise control switch ON, observe the scan tool Cruise Resume/Accel. Switch parameter.

• If the scan tool parameter reads Inactive, replace the cruise control switch assembly.
• If the scan tool parameter reads Active or Invalid, test the cruise control switch signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

Repair Instructions

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

* Cruise Control Switch Replacement
* Programming and Relearning for ECM setup, and programming. Programming and Relearning