P0568

DTC P0568

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0568 00
- Cruise Control Set Switch Circuit

Diagnostic Fault Information






Circuit/System Description

The cruise control switch is an input to the engine control module (ECM). The ECM monitors the cruise control switch signal circuits in order to detect when a cruise control function switch has been activated. The ECM detects a voltage signal when a cruise control function switch is applied.

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 set/coast 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

* A last test failed, or the current DTC, clears when the diagnostic runs and does fail.
* A history DTC clears after 40 consecutive warm-up cycles.

Diagnostic Aids

Ensure that the set/coast switch is not stuck or sticking in the pressed position.

Circuit/System Verification

Ignition ON, Cruise Control Switch ON, verify that the Cruise Set/Coast Switch parameter reads Inactive (OFF). The switch parameter should change to Active (ON) and back to Inactive (OFF) as the switch is pressed and released.

Circuit/System Testing

1. Ignition OFF, disable the SIR system. Refer to SIR Disabling and Enabling.
2. Disconnect the turn signal multifunction switch harness connector X4.
3. Ignition ON, verify that the scan tool Cruise Set/Coast Switch parameter displays Off or Inactive.

^ If the scan tool parameter reads On, Active or Invalid, test the cruise control set/coast switch signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.

4. Connect a 3 amp fused jumper between terminals A and D of the turn signal multifunction switch harness connector X4. Verify that the scan tool Cruise Set/Coast Switch parameter displays On.

^ If the scan tool parameter reads Off test the cruise control set/coast switch signal circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

5. If the circuit tests normal, test or replace the cruise control switch.

Component Testing

1. Ignition OFF, disable the SIR system. Refer to SIR Disabling and Enabling.
2. Disconnect the turn signal multifunction switch harness connector X4.
3. Turn the cruise control ON/OFF switch ON.
4. Test for infinite resistance between terminals A and D of the turn signal multifunction switch.

^ If not the specified value, replace the turn signal multifunction switch.

5. Press and hold the set/coast switch. Test for less than 1 ohm resistance between terminals A and D of the turn signal multifunction switch.

^ If not the specified value, replace the turn signal multifunction switch.

Repair Instructions

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

* Turn Signal Multifunction Switch Replacement