Hello all,
I need a little help. I have a 2006 S40 T5 that the only problem is a rough idle, however I plugged it in and had 35 error codes. I also had oil on the intake under the cover.
Here's what I did:
Replaced spark plugs, ignition coils, Mass flow sensor and housing, PCV Diaphragm, Crank case vent hose, and the O ring on the oil spout. I also cleaned all of the oil off of the engine and all of the electrical connections to the ignition coils. I took out the ECU and cleaned it. I didn't see any corrosion, or bent pins.
Here are the codes I am still getting:
P0445, P0079, P0076, P0102, P0245, P2419, P2401, P0351-55, P0497.
It seems I have a short somewhere, or a bad ground? Any ideas are welcome.
Thanks,
Joe

 

Are these systems on the same wiring harness? Share the same ground?

 

I'd write down all the codes then clear and see what resets after a bit (may take a few days worth of driving to reset long term codes ). Has there been any battery events - ie jump starts, removing the battery while working on the engine etc? thinking here is to rule out a false positive due to a temporary low voltage condition.

 

They all appear to be on the same ground. i have written down all of the codes, and the ones listed are the recurring ones. No jumping, or battery change. No lightning strikes, lol Thanks!

 

You may be on a good track chasing down the ground issues. I'd also look at the ground strap to the battery and other common points - may be due for new cables there.