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.
• | 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
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Values | Yes | No |
---|---|---|---|---|
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. Has the repair been complete? | -- | Go to Step 9 | Go to Step 7 |
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. Did you find and correct the condition? | -- | Go to Step 9 | -- |
8 | Replace the ECM. Has the repair been completed? | -- | Go to Step 9 | -- |
9 |
Does DTC P0565 fail this ignition cycle? | -- | Go to Step 2 | System OK |