Hey all, I browsed through the forum but didn't find what I was looking for, perhaps someone on here can help solve my rabid squirrel electrical issue. For starters, I work on cars a lot but never came across an issue like this.

It started 2 weeks ago, it ran rough long after warming up and running around town. It threw a code P0245 Wastegate Solenoid low, P0268 Cylinder 3 Injector Circuit High, P0271 Cylinder 3 Injector Circuit High. I reset with my trusty ELM327 wireless OBDII module to my phone and it went away for 3 days. It came back for revenge, having no start situations where it seems to only attempt to start on one cylinder. Here's the timeline of sorts.....

Wife's car. She called me with a no start. I showed up and got it started but super rough and missing on 2-3 cylinders at idle. Occasionally there would would be a sound like a minigun which smelt of R143A which I think it either blew a high pressure line or a relief valve. Looking back, I think the relay or some other decision making in the electronics never cycled off the compressor, it ran all the time, thus high pressure. High pressure switch? Relay? I unplugged the control wire attached to the side of the compressor to prevent it from running because it was still spinning when the selector for A/C was off. Hmmm.

The injectors were audibly missing once the engine warmed up, causing the rough idle on cylinder 2,3,4 until either one of two conditions occurred: The cooling fan is running OR the cooling fan is disconnected, in which case the injectors fired without fault and the codes could be reset and the engine was smooth as silk. Completely odd. Of course, that would be too easy, with the cooling fan disconnected during a short drive, the injectors would stop firing under load again. It will eventually stop running all together. I have traced wires, looked for shorting, replaced the cooling fan relay and replaced all coil packs(When I went to disconnect #3 while troubleshooting, the top broke off, all were brittle so I replaced them for longevity). I printed all 130 pages of the Volvo electrical wiring book and spent 4 hours looking at it for answers. I believe there is a short but I am not familiar with Volvo electronics and no idea where to look. I also noticed I got the same smooth idle running when disconnecting the signal wire from the ECM to the cooling fan relay which can't be good.

I have a long 2 year history with this car, my first job researching and replacing the ETM through a Canadian company with magnetic Pot switches, rear door lift cylinders, normal maintenance. I really like this car and I'm too proud to take it to a real mechanic....today.

Has anyone run into this issue before? It's a long strange list of electronic things effecting each other, I almost think it's related to a ground switching wire getting 12 volts. I'm so frustrated. I need a good beer.

Thank you!!!