CAN Bus Controller Problem?

[beechner]

I have a 2007 Boxster (not S) with around 85000 miles. Currently it's sitting quietly waiting for spring but when the time comes it needs to have a problem resolved. Last summer during hot weather it would have temperature gauge failures and oil level reading failures, sometimes with the check engine light coming on. Also it became hard to start when warm. No problem at all when cold or in colder weather. Once the outside temperature gets down to the 40s or 50s it never has any issues. When I read out codes using the Durametric tool there are a number of them all indicating a communication problem with the bus controller. Is it possible for the controller to overheat up there under the dashboard or is it just failing? And if it has to be replaced, what happens if it's replaced and it isn't coded by a Porsche dealer or other facility that has the appropriate device to code it?

[Loren]

Do you have the fault code(s)?

[wvicary]

Any electrical type work done to the vehicle? Has the instrument cluster ever been removed? Please post all fault codes from all modules and can you better describe that hard starting issue... eg: Is it slow to turn over? Excessive crank period? Fires but won't idle...etc

[beechner]

OK, so first off here are the codes that had been reported up through the end of August last year. This first started in the spring so here are the codes from 05/15: C112, C2, P3081, P0195, P0117. Next is 08/14: P0117, P3081, P0195, 8004, C112, C200, 8016. Then on 08/21: C140, C158.Once again, all issues disappeared once the weather cooled. I did replace the battery back in April and followed the instructions on things that needed to be learned after replacement.

Second, the hard starting does seem to be temperature related as well. There is never an issue with a cold start nor if the car has been shut off for just a few minutes, only when having been fully warmed up and then having sat for an hour or so. Then it requires prolonged cranking (normal cranking speed) and does not fire at all initially. After cranking several times it then fires up but roughly. It smooths out and then operates completely normally. It the car sits for several hours there is never a problem getting it to start.

[Loren]

8004 External BOSE amplifier

Fault in front right/rear right loudspeaker channel

Possible cause of fault

- Open circuit, contact resistance or short circuit to B+/ground in the wiring harness

- Loudspeaker faulty

- Amplifier faulty

8016 External BOSE amplifier

Possible cause of fault

- Wiring harness loudspeaker for right door speaker faulty

- External BOSE amplifier output stage faulty

By the way you should clear all the faults and see which ones come back. Now is important not past faults (unless you troubleshooting intermittent faults).