PCM Compressor Fault

Hello Everyone!
Our PCM is giving us a peculiar problem. It constantly switches between a compressor short and the sticky fault caused by that. It runs when the sticky fault is present. There is absolutely no visible short, and it has been rewired several times. We are using 18AWG wire going between our 16AWG compressor and the PCM because 16AWG doesn’t fit. We have determined that it is not a compressor problem, nor is it a message that is a mix of red/orange, as it is too erratic of a change between them. Even the NI Configuration says it is a short. Could there be something wrong with our PCM?

Thanks in advance!

Does it fault when there is no compressor attached?

We had these issues and fixed them. However the next day our PCM died. I do not know if this is going to happen to you but, I would order another just in case.

We will try running without the compressor as soon as we can. Sperkowsky, what did you do to fix it in the first place?

We were/are also having PCM sticky faults. I believe we may have rectified the error by adding connectors to the ends of our CAN wires and PCM power wires.

First we cleared the sticky fault. Then We disconnected everything ran the robot and then finally we reconnected everything.

What do you mean by adding connectors? Can you specify, please?

We used these.
http://www.ctr-electronics.com/cabling/ferrule-16-awg.html

Makes a better holding connection in my opinion. I think we got ours from Digikey for a bit cheaper.

We finally figured it out today! Thanks a lot for your help! The problem was that the firmware was up to date, but it was corrupted. So all we had to do was update the firmware and it worked fine. (We also vacuumed off the PCM because the National Instruments Configuration kept saying it was a compressor short). Anyways we will probably take a look at those connectors because they look like they work a lot better than just plugging the wire straight in. Thanks again.

We had the same problem here on team 171. Turned out the wireless radio was creating interference on the CAN bus. We had the radio right next to the PCM and the power plug was parallel to the CAN connections.
Moved the radio to a location about 6" away and we are no longer having any problems.

Hope our pain helps some other teams out! :slight_smile: