2003 yukon denali

dkautzdkautz paMember Posts: 2
edited December 2018 in GMC
when i hit a bump in the road it shuts down and when i try to restart it the engine goes it to derate mode and has no throttle. what could be the problem?


  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    That's going to be tough to solve. So it stays in default mode or it corrects itself?
  • dkautzdkautz paMember Posts: 2
    no i have to unhook battery to reset computer
  • Mr_ShiftrightMr_Shiftright Sonoma, CaliforniaMember Posts: 64,482
    OK. Well there are quite a few different sensors or modules that can set off the default power mode. What you need to do is read the codes stored, at the time of the fault. The codes might tip you off as to which sensor or module is reacting to the bumps.

    You could also try the "wiggle test" with the truck idling in a 'normal' (not default) state. You can try the wiring near the fuse box, the battery cables, or any harness you can grab onto without cutting off your fingers from the engine cooling fan or belt/pulley system. Be careful when you do this!

    The wiggle test might help you locate the position of fault.

    Sounds like a loose connector or wire somewhere. It could also be in a wheel sensor, so that's why codes are important.
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