02 24v dying, P1694 code

[Yotadzl]

I have been fighting this truck. It is an '02 Cummins 5 speed. The problem is intermittent dying after the engine warms up, roughly 3 miles worth of driving. When it happens the ECM loses communication. It will happen continuously when the engine is hot. It will start, run for a 5-30 seconds, then die. It may start right back up, or it may take a minute or two for it to "reset" and start. The only code that sets is a P1694 Loss of communication with the ECM. This code sets in the PCM when the engine dies.
I remved the Edge Comp box first. I have diagnosed the ECM powers and grounds, both by proving them out with a head lamp bulb and back probing to monitor voltage and ground when the problem occurs. No problem was found there. I diagnosed the bus wires per the chrysler "no communication" diagnostic. No problems were found. I unplugged all the 5 volt sensors I could with the engine running and the problem still occured. I replaced the cam sensor and it did not fix the issue. So I then replaced the ECM, and the problem still occurs.
At this point I am at a loss where to go. If anybody has experienced this issue I would be grateful for some information.

[diesel_importer]

I had a customers truck with loose connector that plugs into the interior fuse box. It was losing comm with pcm/ecm


Sent from my iPhone using Tapatalk

[Yotadzl]

I came across some info about that. I pulled the connector apart and checked the pins, no problem found. I'm assuming it was loose where the two halves are bolted together, not in the fuse box? I have now replaced the PCM with a used one and it still happens. Unhooked the alternator and it sill dies. I ran the engine with the Cummins VP44 bypass tool and the engine stays running, bit the ECM will intermittently lose communication with the scan tool. Beating my head against the wall with this one.

[jlbayes]

Have access to a drb III?

P1694 No Bus Message Received From Companion Module - OBDII Error Codes - Mopar1973Mans Dodge Cummins Forum

[Yotadzl]

Yep thats what I have been using. And WiTech with a DRB emulator. This thing is driving me insane. Thanks for the info. It looks like the Chrysler diagnostic routine I have ran through already though.

[dieselbeef]

welcome to the club

[jlbayes]

I wonder if it is killing the asd relay when the pcm loses the info from the ecm.

[Yotadzl]

I'm not real sure how to verify that. I do know the ECM is not losing power or ground when it dies.

[Yotadzl]

Just an update. I'm pretty sure that I am dealing with a second defective "reman" ECM. I isolated the engine from the rest of the truck by disconnecting the two connectors on the firewall, then jumping power to the required circuits. This eliminates any chance of CCD bus, fuse box, PCM, ETC. causing the issue. The engine runs fine until it gets hot, then starts intermittently cutting out and dying. If I run a hose on the ECM for a minute or so to cool it down, it starts and runs fine until the ECM gets hot again.

On another note, does anybody have a good source for replacement ECMs? I seem to be striking out.

[Mark Nixon]

There are very few people who are actually "rebuilding" these ECMs.
To me, it seems like most of the big name suppliers are actually scooping up all of the cheap ones, even core stashes, and just offering a warranty, using the buyers as a guinea pigs to diagnose issues.

I think both Gary and Yotadzl may both be victims of this scenario and I suggest y'all put their "warranty" to the test.

That being said, with the mortality rate of the 2nd gen ECMs, you'll get proficient at R&R-ing them quickly.

Mark.

[dieselbeef]

well mine came from flagship and theyre real cool about the whole warranty thing,,except transit time to and fro cost me almost 3 weeks so far...I should've went with someone closer..at least in fl..maybe turnaround would've been better.
you understand this crap better than me...I cant unhook anything and make the truck run...idk wtf im doing..even tho im getting some good help im trying like heck

[Yotadzl]

Originally Posted by Mark Nixon

There are very few people who are actually "rebuilding" these ECMs.
To me, it seems like most of the big name suppliers are actually scooping up all of the cheap ones, even core stashes, and just offering a warranty, using the buyers as a guinea pigs to diagnose issues.

I think both Gary and Yotadzl may both be victims of this scenario and I suggest y'all put their "warranty" to the test.

That being said, with the mortality rate of the 2nd gen ECMs, you'll get proficient at R&R-ing them quickly.

Mark.

You are spot on Mark. That is basically what I was finding with ECMs through my connections. Turned out to be a 2nd defective "reman" ECM. Just so strange that it acted almost exactly like the original failed ECM. Like usual though, I learned a few good lessons along the way.

[dieselbeef]

im still waiting on flagship..they are so f/n slow I bought another truck to get my biz back on track

[Yotadzl]

Originally Posted by dieselbeef

well mine came from flagship and theyre real cool about the whole warranty thing,,except transit time to and fro cost me almost 3 weeks so far...I should've went with someone closer..at least in fl..maybe turnaround would've been better.
you understand this crap better than me...I cant unhook anything and make the truck run...idk wtf im doing..even tho im getting some good help im trying like heck

Search "stand alone 24 valve cummins" on YouTube. Thats where I got the info on "hot wiring" the engine. I've been doing this for a lot of years, but there is still new things I learn on an almost daily basis.

[biggy238]

Capacitor plague - Wikipedia

Sent from my XT1575 using Tapatalk

[Yotadzl]

Interesting....