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Isx cm870 intermittent full throttle - Printable Version

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Isx cm870 intermittent full throttle - Witt11 - 05-29-2021

I have an 04 isx cm870. Over the last few months the truck occasionally will rev to full throttle on its own. Sometimes it will do it when the truck is idling other times while I’m driving. It will rev to full throttle for a few seconds then the red stop engine light will come on. After another few seconds if I tap the pedal the light will go out and it goes back to normal. At first when it happened the check engine light would come on and throw a 431 idle validation code. Now the check engine light never comes on and it still happens at least once a day. It seems to happen when the truck is at a higher temperature and since we’re getting into warmer weather it’s been a more consistent issue. I have replaced the tps sensor and also did resistance checks on the wiring from the pedal to the ecm and cleaned all the plugs. I had it plugged in and the tech told me the tps sensor was good, I’ve also ordered a ecm but have not received it yet to try it. It’s definitely been stressing me out driving it with my foot hovering over the clutch all day just waiting for it to go full throttle! Any help would be greatly appreciated!


RE: Isx cm870 intermittent full throttle - Waterloo - 05-29-2021

Is there a delete on this truck? Make, model and mileage?


RE: Isx cm870 intermittent full throttle - Witt11 - 05-29-2021

No delete, 04 kenworth t800, 131,000 miles 7200hrs


RE: Isx cm870 intermittent full throttle - Nostalgic - 05-29-2021

I'd check out the metering actuators?


RE: Isx cm870 intermittent full throttle - Rawze - 05-29-2021

it is common for a metering actuator starting to stick will cause that.


RE: Isx cm870 intermittent full throttle - Witt11 - 05-29-2021

Thank you, that’s where I will go next.