P0568

Schematic:

CIRCUIT DESCRIPTION
The Throttle Actuator Control (TAC) module is a communication link between the cruise switches and the PCM. The cruise Set/Coast switch is an input to the TAC module. This input is then communicated from the TAC module to the PCM across serial data, allowing the PCM to control and hold a requested speed. The Cruise Set/Coast switch sends an ignition voltage to the TAC module when the switch is closed (ON). If the PCM receives an input when the module does not expect it, this DTC sets.

CONDITIONS FOR RUNNING THE DTC
The Cruise switch is ON.

CONDITIONS FOR SETTING THE DTC
The Set/Coast switch is ON for more than 90 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
^ The PCM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
^ The DTC can be cleared by using a scan tool.

DIAGNOSTIC AIDS
Inspect for the following:

A set/coast switch stuck in the engage position or the signal circuit is shorted to voltage.

IMPORTANT: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

^ Poor terminal connection.
Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Diagrams.
^ Damaged harness.
Inspect the wiring harness for damage. If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display may indicate the location of the fault. Refer to Wiring Repairs in Diagrams.
^ Inspect the PCM and the engine grounds for clean and secure connections.

If the DTC is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set.

TEST DESCRIPTION

Diagnostic Chart:

The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the Resume/Accel signal circuit is shorted to voltage.
3. This step determines if the TAC module or the switch is at fault.
4. Inspect for a resume/accel switch stuck in the engaged position or for the signal circuit shorted to voltage.
7. This DTC will not report a pass. The scan tool status for this DTC will never report a pass. The scan tool will only indicate the DTC when the diagnostic fails. The repair is not complete if the scan tool indicates that the diagnostic ran and failed.