P0568

DTC P0568

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 UART serial data circuit. This DTC sets if the PCM receives a serial data signal from the TAC module indicating that voltage is present on the cruise control set/coast switch signal circuit for longer than 90 seconds.

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
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 1-9:

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