The cruise Set/Coast switch is an input to the fuel control portion of the PCM. These inputs allow the PCM to control and hold a requested speed. A Cruise Set/Coast switch sends an ignition voltage signal to the PCM when the Set/Coast switch is ON.
• | The cruise switch is OFF. |
• | The ignition voltage on the Resume switch signal circuit. |
or
• | The cruise switch is ON. |
• | The Resume switch is ON for longer than 25.5 seconds. |
• | The PCM will not illuminate the Malfunction Indicator Lamp (MIL). |
• | The PCM records the operating conditions at the time the diagnostic fails. This information stores in the Failure Records. |
• | A History DTC will clear after forty consecutive warm-up cycles that the diagnostic does not fail (the coolant temperature has risen 5°C (40°F) from the start up coolant temperature and the engine coolant temperature exceeds 71°C (160°F) during that same ignition cycle). |
• | Use of a Scan tool will clear the DTC codes. |
If the Set/Coast switch is stuck in the ON position or the driver is holding the Set/Coast switch ON for longer than 25.5 seconds, DTC P0568 will set. DTC P0568 only checks the signal circuit for a short to voltage.
The numbers below refer to the step numbers on the Diagnostic Table.
This Step determines if the signal circuit is shorted to voltage.
This Step determines if the PCM or the switch is malfunctioning.
Step | Action | Value(s) | Yes | No |
---|---|---|---|---|
1 |
Important: Before clearing any DTCs, use the Scan Tool Capture Info to save freeze frame and failure records for reference, as the Scan Tool loses data when using the Clear Info function. Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to A Powertrain On Board Diagnostic (OBD) System Check | |
2 |
Does the Scan Tool display the Set switch ON? | -- | ||
3 |
Is the test light ON? | -- | ||
4 | The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If any additional DTCs were stored, refer to the applicable DTC tables first. Are there any additional DTCs stored? | -- | Go to the applicable DTC table | Go to Diagnostic Aids |
5 |
Is the action complete? | -- | -- | |
6 |
Important: The new PCM must be programmed. Replace the PCM. Refer to PCM Replacement/Programming . Is the action complete? | -- | -- | |
7 |
Does the Scan Tool indicate the diagnostic Passed? | -- | ||
8 | Does the Scan Tool display any additional undiagnosed DTCs? | -- | Go to the applicable DTC table | System OK |