Help, Cummins Down..........1694 PCU Code

[winch_warrior]

Truck just died on side of Interstate. Pulled codes off dash......DTC P1694: NO BUS MESSAGES RECEIVED FROM COMPANION MODULE. PDC plug seems to be ok. Faulty ECM ?  What else could it be?

Edited July 7, 2019 by winch_warrior

[Mopar1973Man]

Here is the wiring diagram. Then here is the CCD network article.

 

[winch_warrior]

Thanks Mopar1973Man. So after checking over wiring, verifying good grounds and not seeing anything obvious that stands out, would everyone concur bad ECM?    P1694 code.

Auto Computer Specialist seems to be a reputable repair facility? 

[Mopar1973Man]

@Auto Computer Specialist will test the ECm before even starting a repair and then notify you of what has failed as well.

[winch_warrior]

Sent my ECU to get repaired...........In the meantime, Question for you all..........What would it hurt if I found a "spare" ECM to have as "backup" when I'm out in the mountains here in Colorado? There is no cell service in several places in the mountains where a majority of my time is spent. Calling for help with no service is a reality and having a "backup"  ECM makes sense to me with where I'm located and working. Having a "spare" ECM would allow me to "limp" back home. What would it hurt? Affect mileage reading on dash? What's your thoughts?  

[Mopar1973Man]

Not worth it. 

 

17 years later I'm on the same ECM. You would have to send that spare in and have it reflashed with your software. There is 52 different version of software per year. 

 

You would be better off doing the W-T ground wire mod. Then doing the PCM protecting fuse. Way cheaper and no need to buy a second ECM and have it flashed.

 

 

[dripley]

Good advice above for the health of the truck electronics. Lost my oe ECM back in 2010. Was not any fun. You can carry a spare but what if the tranny goes or the PCM or the fuel pump or anything else that might stop the truck. I would not hesitate to pack my 02 and go anywhere. If it breaks, it breaks and I will have to deal with it. 

What ever I carried as a spare would not be what broke.

[Mopar1973Man]

Yup... Like myself I blew my PCM, broke the mainshaft in the transmission, blew up the driver side front wheel bearing. Forget the idea of spare parts...

[winch_warrior]

I'll take a look at these PCM, W-T ground wire mod. and alternator articles. Thanks!