ECM power supply lost with ignition turned on...

[Meatbag]

New guy here, been lurking awhile. I have a 2010 Prostar with a CM871, and every so often I will get a CEL with that description. It only lasts a few seconds, truck stays running but I have no throttle. When the CEL goes out, I can take the truck out of gear, put it back in and drive away like nothing happened. Possibly related: Sometimes when I turn the key to start the truck, I get nothing and it will take 2 or 3 turns to start. Any ideas?

[Rawze]

Check the grounds out by the starter and the ignition key switch for intermittent connections too.

it could also be one of these fuses mentioned here...

http://rawze.com/forums/showthread.php?t...1#pid12861

[Meatbag]

Thanks Rawze!

[JMBT]

Meat bag, do you have an auto trans?? If so, sometimes the engine crank relay circuit will do those types of things if it has an intermittent short to ground. I also had a truck one time that had a similar staring issue. It turned out to be the factory installed battery disconnect switch. Just another couple
Things to check.

[Meatbag]

No auto, I have a 10 speed. Sorry, I should have specified that.

I checked the grounds and they were good, battery cables were tight and starter cables were tight also. I changed out the fuses that were outlined in that other thread. Those 5 amps on the left were extremely tarnished which I was glad to see, but new ones aren't fixing my problem.

I haven't dug into the ignition wiring yet, I suppose I could change out the relays as well. I'll update again tomorrow. Any more advice is greatly appreciated.

[Meatbag]

So I replaced the ignition switch and found a few wires on top of the transmission that were rubbed through. Rerouted those and secured them properly to no avail. All can think of now is that there is a DPF sensor involved some way, somehow. A quick scan is showing 3 active codes. Mighty frustrated at this point.

[Rawze]

Cummins code 1117 (Power Supply Lost With Ignition On - ...) is also commonly seen during re-programming of the ECM. The code is basically saying that the ECM has been reset for some reason without the power being cycled properly. It is quite normal to see the code pop up after a flash, then need to be cleared once... but for it to happen without someone re-flashing the ECM is not common to see at all. It is usually related to power wiring issues either by the main power harness or the ignition switch circuits.

I would not rule out a corrupt ECM program or a failing ECM possibly causing it too.

[ZeroNthedark]

(02-13-2018 )Rawze Wrote:  Cummins code 1117 (Power Supply Lost With Ignition On - ...)

Had a very similar code, 0434, after a breakdown. Truck was running fine, went to upshift, and kaput! Died and wouldn't restart. Went through the trouble shooting tree until I found that my cranking voltage was under 6 volts. Replaced the 4 year old batteries and no issues since.

Don't know if that was really the reason or not, but since it worked that's the story I'm going with.

Great tip about the ECM being a problem.

[Signature620]

I usually see 1117 caused by:

- Weak batteries as explained by ZeroNTheDark
- High resistance between batteries and the 4 pin connector @ ECM
- Drivers turning off the battery isolator as soon as they turn the engine off.

Anything that effects unswitched power to the ECM or disrupts it's powerdown cycle will give this code.