JeffDallas

2008 Cayman S

Last winter we had extreme cold: When I first open the driver door to get in, loud popping and static from speakers. Like full-blast amplifier volume for 1-2 seconds. Even before I put the key in. And I think even if radio is powered off (unconfirmed).

In warm months that problem went away completely, no problem.

A year later, cold again. On cold days there is no sound at all through the speakers. Radio turns on, can change radio stations etc. But no sound.
When it warms up later in the day (above 60 degrees F) then the radio/amp/speakers work perfectly.

Is this a bad amp, a bad CANBUS relay, wire shorting in the driver door?
Please help if you've seen this type of problem

ga 951

I had a problem with my amp (non-bose. 9 speakers). Although I didn't have the temperature issue, mine exhibited the same symptoms. PCM would be powered and operational, but no sound. After a period of time, I would get a loud pop (like an amp coming on) and the speakers would work.
I replaced the amp with another oem (ASK) amp and that solved the problem.
If you have a Bose system, I don't have any experience with that.

JeffDallas

Thanks for the reply. Yes its the Bose system.

When your amp would pop and kick on, would that be random while driving? Or you mean next time you started the car?

If mine doesn't come on when I open the door and insert key then it isn't going to come on at all.
The moment of truth appears to be opening drivers door to enter the vehicle. Some sort of CANBUS signal or something is supposed to trigger amp and interior lights etc??? IDK

I was thinking maybe some sort of short in the door wiring. Prevents amp from getting power relay signal. Or maybe the door and relay signal are fine but amp just won't power up in colder weather.

ga 951

In the beginning, the amp would fail intermittently on start up. Sometimes it would not come on at all and then at some point in the drive it would make a loud pop and there would be sound. Towards the end, it never came on after start but sometimes would come on later during the drive. When that happened, it would stay powered until shutdown. For me, the door or temperature did not seem to matter. When I put key in ignition the PCM powered, but no sound.
My research showed the ASK amp had inherent problems and failure was not uncommon. I'm not sure if the Bose system uses the same amp.

Here are some wiring diagrams that may help.

ga 951

After looking at the last diagram, I see your system uses a different amp, so I’m sure how helpful my posts were

Julian_KCMO

I have this EXACT same problem, except it's not confined to the colder months here in Kansas City, I have the intermittent availability of sound all year round.

I need to find another local BOSE optioned 987 owner to try swapping the amp out and see what happens.

I hope we can find the solution.

Cheers,
Julian