2017 Pacifica CAN hi / low

2017 Chrysler Pacifica CAN hi / low good waveforms and then randomly bad waveforms...troubleshooting drivability issues...any inputs greatly appreciated! Thanks.

Any codes? Any symptoms?? Those waveforms look bad

Are you at the DLC, or one of the CAN C modules?

I'd suspect a bad module ground, since the bias is going above 2.5V in the bad captures.

There are 37 modules on this van and once the car acts up I get around 20 "U" codes on various modules not communicating with each other. It is very intermittent when the van does act up. It will run fine and my oscillospoce shows good CAN hi and CAN low waveforms but once it acts up, I get bad CAN hi and CAN low waveforms. The problem is it only acts up every few days only for 15 minutes or so. When it does act up everything is going crazy and I cannot shift the vehicle out of park either. The pictures of the bad waveform seem to be the 2.5vdc idle (rececessive state voltage) that is going crazy. I am at the DLC with a breakout box doing my scope work. Any help is greatly appreciated.

can you post a wiring diagram of the network?? i dont think all 37 of those modules would be on the high speed network.

cheryl hartkorn wrote: can you post a wiring diagram of the network?? i dont think all 37 of those modules would be on the high speed network.

It is 7 pages. :woohoo: That would be 14 screenshots and uploads (the way I, usually, post diagrams)

Trying something new...




Well,...that didn't turn out so well. Converting to .pdf lost the color. :dry:

Here is the CAN "C" bus wire diagram...I wonder if these issues is a software issue perhaps?

The issues only seem to be on the CAN "C" Bus and not the CAN "IHS" Bus.

So we’re not worried about the pins 6 and 14?? It’s possibly can c part of the network??

I am measuring off of pins 6 and 14 for CAN hi and CAN low; that is where I am getting my data.

Tyler wrote: I'd suspect a bad module ground, since the bias is going above 2.5V in the bad captures.

I agree with Tyler. If you find the "Start Connector", you can remove modules, 1 by 1, from the network.

I can get to the star connector, but the problem is that it is very intermittent and when it does act up it only does it for about 5-7 minutes each time and then it goes back to normal.

I found the problem. It was a loose connection at the star connector.