ISX to x15

[Manjot12dosanjh]

Someone swapped an ISX cm2250 for an X15 Cm2350, they used a harness off of a 2014 kenworth t800 that had cm2350 ISX, problem is everything works fine just the acceleration pedal doesn’t work, codes I get are 4149, and 4289, I’m getting 5 volts, and ground, I bypassed all the wiring and hooked up the pedal straight too the ecm, still same codes. Swapped into a 2012 Kenworth w900

[Rawze]

what ecm and wiring harness was used for the replacement engine?.

[Manjot12dosanjh]

(01-15-2026 )Rawze Wrote:  what ecm and wiring harness was used for the replacement engine?.

Used the x15 ECM, I was reading that cm2250s used dual analog sensors is that correct?

[Bengy88]

In a perfect world they would have used the harness and ecm from the engine that was originally in the truck as there are a few of us that can make them run 100% safely that way. When you start swapping the engine harnesses etc in an attempt to make one run there are always issues like this. Specifically with coolant level sensors and throttle position sensors. It can be made to work but requires a ton of research and comparisons both ways and you usually end up re wiring the accelerator and changing the tps sensor.

[Rawze]

yeah, the original ecm and engine wiring harness for the truck should have been re-used.