Mitsubishi Repair Problems? Ask a Mechanic for Answers ASAP
The AT relay fault can happen as a result of an actual relay or as a side effect of the system going into fail safe. The transmission fail safe is accomplished by shutting off power to the AT relay, and if it happens fast enough this can sometimes trip the AT relay fault as well, even though it is just doing its job.
I would suspect that they might have misplaced a relay considering they were just working on the relays. Can you get a photo of your relay panels so I can make sure everything is in the right place?
They are not nearby (the fuel pump relay is under hood, the AT relay is in the foot well), however keep in mind as I mentioned before if there is another problem to put the transmission into fail safe, it will trip the AT relay fault as well even though it is OK.
Considering that they just did this work and now you have the AT relay fault and fail safe behavior immediately after, my first suspicion is they had some relays out and didn't get back in or went into the wrong spot etc.Have they scanned the transmission controller to see if there are additional/different faults there (not an OBD scan)?
Sounds good, I'll be here.