P0351 code

nojamin · Post by **nojamin** » 08 Dec 2019, 21:23

Just replaced 4 of the 5 coils(cylinder 3 had already been replaced previously and is not throwing a code). I'm getting P0351, 352, 354,355 code. It's not turning the check light on but I'm wondering if those are interfering with the Cat Mon readiness test not to be ready,( I've done the drive cycle thing A LOT) which is required in NY for the car to pass inspection. Engine runs nice and smooth now. They are cheap aftermarket coils. Is there something to do so the computer knows they're there?

Post by **abscate** » 09 Dec 2019, 07:36

It might be those cheap coils the ECM is not happy about them. Bosch are good replacements and half the cost of OEM Volvo.

The P035x codes arent misfires, but primary/secondary voltage failures.

Make sure your bolts (M6, 10mm head) are firm (don't go crazy, but they need to be clean and wrist tight) to make a good ground connection on your coils. Make sure you get a nice click when you seat each coil electrical plug.

Im guessing those codes inhibit CAT testing and monitor readiness, yes.

nojamin · Post by **nojamin** » 11 Dec 2019, 12:44

Appreciate the response. This "particular" vehicle also has a few other issues. One being the AWD is not functioning. If you could give me a good place (hints, tips, tricks, voltage readings, website) to start for diagnosing this, I would greatly appreciate that! It had gotten stuck in the mud and the back wheels tried to turn slightly, i don't know if that means anything but some "light" would help. Thanks in advance.