For 1990-2009 cars

### Circuit Description

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.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0565 Cruise Control Switch Circuit

### Conditions for Setting the DTC

• | The engine is running.

• | Battery voltage is greater than 7.9956 voltage.

• | The ECM detects the switch is switching too quickly.

### Action Taken When the DTC Sets

• | 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.

### Conditions for Clearing the MIL/DTC

• | A history DTC will clear after 40 consecutive warm-up cycles without a fault.

• | DTCs can be cleared by using the scan tool.

• | Disconnecting the ECM battery feed for more than 10 seconds

### Diagnostic Aids

Inspect for internments and poor connections. Refer to Testing for Intermittent Conditions and Poor Connections .

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step tests the cruise control ON/OFF switch using the scan tool.

1. This step tests the cruise control ON/OFF switch signal circuit.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle | Go to Step 2 | Go to Diagnostic System Check - Vehicle
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 |

1. Switch OFF the ignition for 10 seconds.
2. Operate the vehicle within the conditions for setting the DTC.

Does the DTC fail this ignition cycle?

Go to Step 4

Go to Diagnostic Aids

4 |

1. Disconnect the cruise control switch.
2. Using the scan tool, view the cruise control ON/OFF switch status.

Does the scan tool display Active?

Go to Step 6

Go to Step 5

5 | Replace the cruise control switch. Has the repair been complete? | Go to Step 9 | Go to Step 7
6 | Inspect the cruise control ON/OFF switch signal circuit for a short to voltage. Did you find and correct the condition? | Go to Step 9 | Go to Step 8
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 . Did you find and correct the condition? | Go to Step 9 | --
8 | Replace the ECM. Refer to Control Module References for ECM replacement, setup, and programming. Did you complete the replacement? | Go to Step 9 | --
9 |

1. Using the scan tool, clear the DTCs.
2. Switch OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the conditions for setting the DTC.

Does DTC P0565 fail this ignition cycle?

Go to Step 2

System OK