I was getting an ECM code for the fuel pump (ECM-2900) so I decided to check if there was something fishy with the ECM. I disconnected the battery and removed the ECM, eveything looked good. I sprayed some electrical cleaner and placed the ECM back in. So far so good.
I then decided to verify if the little fan behind the ECM and TCM was still good (I thought maybe the ECM was overheating due to a failing fan). Now this is where my memory is a bit blurry as I'm not sure if the battery was connected or not when I removed the fan. Anyway, when I removed the fan, I accidentally touched the ECM with the exposed wires on the fan motor (bad design imo but I digress). I thought nothing of it at the time, but when I started the car again, I suddenly had many ECM codes (BCM miscommunication and accelerator pedal miscommunication are the ones I remember). The car was also in "limp mode" and the AC compressor wasn't working.
I thought I somehow damaged the ECM while removing it so I sent it to XeMODeX to transfer to a new unit and indeed, my unit was fried. When I received the new unit, I placed it back into place but when I tried to start the car, nothing. I scanned it and all the ECM codes were still there, even after clearing them, but there was also a new code : ECM-710B, which sets up the immobilizer.
While probing around to try and understand the issue, I came accross a blown fuse in the engine compartment. Fuse 8 which is connected to the "cold box fan", the same fan that I accidentally touched the ECM with (fuse 8 is also connected to the accelerator pedal and the AC compressor). So I changed the fuse, cleared the codes and voilà! they all disappeared, including the limp mode... except the ECM-710B code is still showing.
So, is it possible that when I shorted the fan and the ECM, I also shorted a connector between the ECM and the CEM, therefore throwing code ECM-710B? Or is it possible the XeMODeX didn't transfer correctly the immobilizer code from my old ECM to the new unit? I guess I will contact XeMODeX first thing tomorrow but I wanted a second opinion
The cold box fan I'm talking about is shown here for anyone wondering : https://youtu.be/pqCzHmM03mU?feature=shared&t=258
Thanks!
