The cruise control switch is an input to the engine control module (ECM). The ECM monitors the cruise control 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.
This diagnostic procedure supports the following DTC:
DTC P0565 Cruise Control Switch Circuit
| • | Engine is running. | 
| • | Battery voltage is greater than 7.9956 voltage. | 
| • | The ECM detects the switch is switching too quickly. | 
| • | The malfunction indicator lamp (MIL) will not 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. | 
| • | The A/C compressor operation will be disabled while the low voltage indication exists. | 
| • | A history DTC will clear after 40 consecutive warm up cycles without a fault. | 
| • | DTC(s) can be cleared by using the scan tool. | 
| • | Disconnecting the ECM battery feed for more than 10 seconds. | 
Inspect for internments and poor connections. Refer to Testing for Intermittent Conditions and Poor Connections .
The numbers below refer to the step numbers on the diagnostic table.
Step  | Action  | Values  | Yes  | No  | 
|---|---|---|---|---|
Schematic Reference: Cruise Control Schematics Connector End View Reference: Component Connector End Views  | ||||
1  | Did you perform the Diagnostic System Check - Vehicle  | --  | Go to Step 2  | |
Using the scan tool, view the cruise control ON/OFF switch status parameter. Does the scan tool display active?  | --  | Go to Step 4  | Go to Step 3  | |
3  | 
 Does the DTC fail this ignition cycle?  | --  | Go to Step 4  | Go to Diagnostic Aids  | 
4  | 
 Does the scan tool display Active?  | --  | Go to Step 6  | Go to Step 5  | 
5  | Replace the cruise control switch. Refer to Cruise Control Switch Replacement . Did you complete the replacement?  | --  | Go to Step 9  | --  | 
Inspect the cruise control ON/OFF switch signal circuit for a short to voltage. Refer to Testing for a Short to Voltage . Did you find and correct the condition?  | --  | Go to Step 9  | Go to Step 7  | |
7  | Inspect for shorted terminals or poor connections at the engine control module (ECM) wiring harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?  | --  | Go to Step 9  | Go to Step 8  | 
8  | Replace the ECM. Refer to Control Module References . Has the repair been completed?  | --  | Go to Step 9  | --  | 
9  | 
 Does DTC P0565 fail this ignition cycle?  | --  | Go to Step 2  | System OK  |