I have both these fault codes changed coils and plugs on cylinder 2 and 5, no joy , checked all wiring back to the DME , replaced VVT on bank B, no Joy .Reset codes but codes are still present, starts up fine leave ticking over and goes back into fault again PCM deactivation etc,I’m at loss other than changing the VVT on. Bank A ,anyone experienced this?
I'm not a Porsche tech but I have studied the Porsche service documents quite a bit, albeit for the 987.1 cars I'll make some suggestions.
You don't say what diagnostic device you are using. A simple "code reader" may not be enough. If I were using my Durametric reader in this situation, I would look for Misfire codes on the subject cylinders. If you are not getting Misfire codes, that generally indicates that your plugs are firing, which confirms the plugs and coil packs as being operational. Conversely, misfires, sensed by deviations from learned patterns in the crankshaft rotational accelerations, can come from a number of causes, beyond plugs and coil packs. Porsche service training for OBDII indicates that for a component like the coil pack, it is checking for shorts to ground, open circuits, and sensor logic. In this case sensor logic is most likely the static resistance of the coil pack being within a certain range. BTW, the Durametric can do a Freeze Frame of the last event that threw a code. Sometimes this can be helpful.
It sounds like you have covered the basics i.e. changing the plugs, coil packs, and checking the wiring. Going a little further, I would have simply swapped two adjacent coil packs/plugs and seen if the problem followed the coil pack. You can still do this. Next, I would go to the ECU harness/plug, identify the 3 wires from the various coil packs, and make some comparative measurements between the ones with a problem and the ones without a problem. Again, you are looking for shorts, opens, and non-typical resistances.
You mention VVT. Personally, I don't see any connection between valve timing and your symptoms. Unfortunately, the next plausible culprit is the ECU. If you had a known good one to swap in that would be good. Or you could send it to one of the ECU repair services.
A Hail Mary would be to do a cold reboot on the ECU. Disconnect the battery for 1/2 an hour. You'll get some new codes but most of them will go away with a little bit of driving.
At that point, it might be time to take it to a dealer or an independent with the right diagnostic equipment.
Good luck!
Looks like this is a duplicate thread, original over here...
https://www.planet-9.com/threads/p0325-and-p0355-codes-primary-secondary-circuit-open.255925/?post_id=2230295#post-2230295
