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+--- Thread: Random shuttoff (/showthread.php?tid=10791)
Random shuttoff - medicsaps - 10-22-2026
Truck is a 2006 9900I ISX cm870. I’m having an intermittent problem that is getting worse everyday. Truck looses power briefly but keeps running and the only code I get is by 434. At first it was every month or so but now it’s becoming more frequent. This started after driving down an Air Force range road that was paved washboard type bumps, it shutoff 11 times in 3 miles before I could get my load delivered. When it started it would only happen after driving 100 miles or so. I run the same route most of the time and it would shutoff in the same places. One place is where a 4 lane goes to two 65 mph to 55 mph. Second place is after driving through some Alabama hills and making a rt turn usually about an 1/8 it will cutoff 3-4 times. Now it’s more random places along the route. Certain numbs will cause it and sometimes it’s right turns. When this happens speedometer goes to 0 mph and mileage goes back to last place it was turned off. Here’s a list of things that I have tested and replaced: not in any order
Batteries
Checked battery wires and replaced bad ones.
Replaced key switch
Replaced Ecm
Replaced fuel lift pump (leaking)
Replaced fuel shut off
Replace a timing actuator that was leaking
Replaced throttle position actuator
Load tested “with the old head light bulb test” Ignition wire to Ecm
Load tested every Ecm wire circuit with same head light
Did a fused overlay, with new fuses,for Ecm power and added another fuse overlay to fuel lift pump to ensure it wasn’t grounding or shorting the Ecm power wires.
Removed and cleaned every ground I can find Eng block both firewall connectors and fuse ground inside the truck.
I’m sure there is a few more things I’m missing but please chim in if you have any ideas this thing is about to drive me crazy. Thanks in advance.
RE: Random shuttoff - Rawze - 10-23-2026
Your description is vague. is the engine cutting out and shutting off?.. or is the dash?... and the engine fuel pedal not responding?.
you were not very clear on "WHAT" is actually happening.
== First of all, the ecm on CM570/CM870/CM871's is notorious for being flaky. You say you replaced ECM but this does not good if you did not get a 100% certified OEM ecm from a certified stealers%it. Most used/reman ecm's on the market for those trucks any more ARE IN FACT FLAKY by now. - A new/reman from 100% certified stealers%it will always have a brand new circuit board in them .. and this is the only way to go to ensure you did not get another flaky ecm. Banging on the ecm (hard enough to almost dent its casing) at idle will typically reveal this issue... as engine will cut out briefly when it acts up... at top left area, from top down, and/or near middle right area especially.
Next...
== Internationals in particular also suffer issues with the dash, cab controller, etc.. where the fuses in the fuse panel get tarnished, but are not bad ... and then cause slight voltage drops here and there, making the cab, cluster,. or other components do some really flaky things. - Here is an article on this ... and it is a VERY common issue with them. - I have to replace all my fuses every 2-3 years because of this on my own truck. That is how common it can be...
info: https://rawze.com/forums/showthread.php?tid=1514&pid=12861#pid12861
RE: Random shuttoff - medicsaps - 10-25-2026
It cuts off and I get a code 0434 power off with key switch on. The red stop light flashes but goes out and the engine warning light illuminates but then it keeps running. Turning truck off will make the code inactive. The Ecm is from Cummins. My old Ecm was put into another truck and it is running with no issues.