PCM not taking Feedback/Control and Compressor not turning on

Status light on PCM is green but when robot enables gives CAN timeout and the Compressor does not respond.

do you know if the can bus is terminated correctly?

We looked over the CAN loop and everything looked correct.

Make sure it shows up in the Phoenix Tuner. Also, check to make sure the CAN ID is set to 0 (for default value or to whatever number you are using in code). Changing the CAN ID off the default in the tuner is a quick and easy way to make the compressor stay off (which I do sometimes for long demos).

Our issue is that it won’t turn on or responding to any commands. We’ve self-tested on Diag Client and it gave us 0 faults as well.

If you know that you have the CAN device ID the same in both the code and what you see in the tuner, then I guess the next step would be to re-install firmware (and possibly reset the device configuration to factory settings – I forget if PCM has that option).

Edit: But honestly I would check the first part very carefully. Because you’d be seeing what you are seeing if they are not the same number. And it could happen either at the Tuner (by changing the ID) or in the code where you initialize the PCM.

Also, which compressor are you using. The black 1.1 cfm from AM has shorting issues (they pulled it from there store) my team had the same issue. We swapped out everything from pcm to p switch except compressor and it only worked sometimes so check that.

Make sure the PCM is not close to the radio.

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+1 to this.

I know it sounds crazy but if the PCM is close to the radio the compressor will not turn on ( and none of us are smart enough to figure out why)

so put a good 8 inches of space between the radio and PCM