P0568

DTC P0568

CAUTION: Refer to SIR Caution in Service Precautions.

Disable the inflatable restraint steering wheel module when performing this diagnostic table. Refer to SIR Disabling and Enabling Zone 3 in Restraint Systems.

Circuit Description
The cruise control set/coast switch is an input to the throttle actuator control (TAC) module. The TAC module uses the cruise control set/coast switch signal circuit in order to detect when the driver has requested to set the vehicle speed or to decelerate the vehicle speed. The TAC module detects a voltage signal on the cruise control set/coast switch signal circuit when the switch is applied. The TAC module sends a serial data signal to the powertrain control module (PCM) via the universal asynchronous receiving/transmitting (UART) serial data circuit indicating the status of the set/coast switch.

Conditions For Running The DTC
- The ignition is ON.
- The cruise control switch is ON.

Conditions For Setting The DTC
The PCM receives a serial data signal from the TAC module indicating that the set/coast switch is ON for longer than 90 seconds.

Action Taken When The DTC Sets
- The PCM stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.
- The cruise control system is disabled.

Conditions For Clearing The MIL/DTC
- A last test failed, or the current DTC, clears when the diagnostic runs and does not fail.
- A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic.
- Use a scan tool in order to clear the MIL/DTC.

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 PCM Cruise Control Data data list. This will help eliminate the possibility of a internally open or shorted inflatable restraint steering wheel module coil.
- Ensure that the set/coast switch is not stuck or sticking in the engaged position.
- For an intermittent condition, refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.

Test Description

Steps 1-2:

Steps 3-8:

Step 9:

The number below refers to the step number on the diagnostic table.
2. This step determines if a condition is present.