Cruise control won't engage on Freightliner Cascadia - Code P0565

Question

I'm having a hell of a time getting my cruise control to turn on during long hauls. The dash indicator doesn't even light up when I toggle the switch, and it's throwing a P0565 active code. I checked the dash harness and things look okay, but the ECM won't see the request.

turbo_tony · Accepted Answer

The issue was eventually traced to a corroded connector at the bulkhead passthrough (Pin 14 on the black connector). After cleaning the pins and applying a bit of dielectric grease, the P0565 code went inactive. Total cost was just the shop labor time for the circuit trace, and the cruise control now engages perfectly on the first click.

Pete Sanders · Answer

You need to look at the diagnostic data on your scan tool to see if the brake pedal switch or clutch switch is biased high. If the ECM thinks you're pressing the brakes, it will reject the 'Cruise ON' signal every time.

fleet_chief_42 · Answer

Check the wiring harness where it passes through the firewall. Rubbing on the bulkhead can cause a short to ground on the signal wire, specifically the wire labeled 422 in the Freightliner schematic.

Jordan Lee · Answer

Check the clock spring under the steering wheel. If you have any other issues like the horn or volume buttons acting up, that's usually the culprit for the cruise signal not reaching the module.

Cruise control won't engage on Freightliner Cascadia - Code P0565

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