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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

Circuit/System Description

The cruise control resume/accel switch is an input to the engine control module (ECM) / powertrain control module. The ECM (5.3L) / PCM (3.8L) uses the cruise control resume/accel switch signal circuit in order to detect when the driver has requested to accelerate the set vehicle speed or to resume the cruise control system. The ECM/PCM detects a voltage signal on the cruise control resume/accel switch signal circuit when the 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 60 seconds.

Action Taken When the DTC Sets

* The ECM/PCM stores the DTC information into memory when the diagnostic runs and fails.
* The malfunction indicator lamp (MIL) will not illuminate.
* The ECM/PCM records the operating conditions at the time the diagnostic fails. The ECM/PCM 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

Perform the following in order to avoid misdiagnosis:

* Rotate the steering wheel to both steering stops and activate each cruise control switch separately. With a scan tool, observe the associated cruise control switch parameter in the ECM/PCM Cruise Control data list. This will help eliminate the possibility of an internally open or shorted inflatable restraint steering wheel module coil.
* 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 OFF, disconnect the harness connector at the cruise control switch.
2. Ignition ON, cruise control switch ON, observe the scan tool Cruise Set/Coast Switch parameter.

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

Repair Instructions

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

* Turn Signal Multifunction Switch Replacement
* Programming and RelearningProgramming and Relearning