Circuit Description
The cruise control set/coast switch is an input to the engine control module (ECM). The ECM 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 ECM detects a voltage signal on the cruise control set/coast switch signal circuit when the switch is applied.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0568 Cruise Control Set Switch Circuit
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The cruise control On/Off switch is ON. |
Conditions for Setting the DTC
| • | This DTC sets if the ECM Detects a voltage signal on the cruise control set/coast switch signal circuit for greater than 60 seconds. |
| • | This ECM runs this diagnostic every 0.05 seconds. |
Action Taken When the DTC Sets
| • | The ECM stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The ECM records the operating conditions at the time the diagnostic fails. The ECM 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 Conditions and Poor Connections in Wiring Systems.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Cruise Control Schematics Connector End View Reference: Lighting Systems Connector End Views or Engine Control Module Connector End Views in Engine Controls - 3.6L (LY7) | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Does the Cruise Set/Coast Switch parameter display On? | Go to Step 3 | Go to Diagnostic Aids | |
3 |
Does the Cruise Set/Coast Switch parameter display On? | Go to Step 4 | Go to Step 5 |
4 | Test the cruise control set/coast switch signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
5 | Inspect for poor connections at the harness connector of the multifunction switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
6 | Inspect for poor connections at the harness connector of the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
7 | Replace the multifunction switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column. Did you complete the replacement? | Go to Step 9 | -- |
8 | Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | -- |
9 |
Does the DTC reset? | Go to Step 2 | System OK |
