Circuit Description
The cruise control switch is an input to the engine control module (ECM). The ECM monitors the cruise control set/ coast and resume/accelerate switch signal circuit in order to detect when a cruise control function has been requested. The ECM detects a specific voltage signal on the cruise control set/coast and resume/accelerate switch signal circuit when a cruise control function switch is activated, with each switch having a different predetermined voltage value.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0564 Cruise Control Multi-Function Switch Circuit
Conditions for Setting the DTC
This DTC sets when the ECM detects an invalid voltage signal on the cruise control set/coast and resume/accelerate switch signal circuit.
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The ECM will record operating conditions at the time the diagnostic fail. |
| • | This information will be stored in the Freeze Frame and Failure Records buffers. |
| • | A history DTC is stored. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn off at the end of a consecutive validation cycle in which the diagnostic runs without a fault. |
| • | A history DTC will clear after 40 warm up cycles without a fault |
| • | DTC(s) can be cleared by using the scan tool |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Cruise Control Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the voltage measure at the specified value? | B+ | Go to Step 3 | Go to Step 7 |
3 |
Do the cruise control function switch resistance values measure between the specified values? | Switch OFF=∞ Switch ON=0 ohms | Go to Step 4 | Go to Step 5 |
4 | Test the cruise control set/coast and resume/accelerate switch signal circuit for a high resistance, a short to voltage, or a short to ground between the cruise control switch and the engine control module (ECM). Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 6 |
5 | Inspect for poor connections at the connector of the multifunction switch. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 8 |
6 | Inspect for poor connections at the harness connector of the ECM. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 |
7 | Repair the high resistance in the ignition 1 voltage circuit. Did you complete the repair? | -- | Go to Step 10 | -- |
8 | Replace the cruise control switch. Did you complete the repair? | -- | Go to Step 10 | -- |
9 | Replace the ECM. Did you complete the replacement? | -- | Go to Step 10 | -- |
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
