I have a 2006 Carrera Cabriolet that I brought to an audio installer to have a Pioneer Avic 7100 put in. Since the install the PSM failure alert will come up along with the ABS alert on the dash. Also, when that happens the buttons to turn on the heated seats, recirculate, AC off and defroster buttons do not work or respond. If I stop the car and **** it down and lock it, and then get back in and start the car, all the alerts go away and all the buttons including the PSM work normal. It happens randomly and without warning. I brought the car back to the audio installer, who removed the radio and checked all connections. He said that everything was plugged in correctly and that it could be the cam bus? or a computer board? Does anyone have any ideas before I bring the car to the dealer and incur fees, since I do not have a warranty on this car. Any help is appreciated. Thanks Dan

 

Here's my wild-*** but somewhat educated guess, but it corresponds to a comment your installer made. The correct term is "CAN Bus". Porsches have used this technology for data communications between electronic components since the 996 days (or maybe earlier?). When a CAN Bus component is unplugged (your PCM for example), the free end must be properly terminated or the resulting noise on the unplugged end can cause communication errors on the bus, possibly resulting in the problems you are seeing.

I'm guessing that a proper terminator wasn't placed on the end of the CAN Bus connection that was previously plugged into the PCM. The noise eventually causes a communications error that interferes with the things you describe. Restarting the car resets the computer and clears the communication errors temporarily. If you read the codes on the OBD-II connector (AutoZone will do this for free if you don't have one) you will probably see a code reporting something indicating this.

Your installer should have installed a proper terminator (if my assumptions are correct). You can buy them online but you'll need to find out the connector style first.

 

+1 on that guess. If you look at some of the posts from earlier Carrera and Cayman days with PCM 2.0 or 2.1 people actually ran the CAN BUS wires to the trunk and left the stock unit plugged in because w/o it there would be errors.
Units like MOST-HUR use CAN BUS so there are no issues there. I have the MOST-HUR/997 with a Parrot Asteroid Smart unit and no errors.


Find out how did the installer interface the new unit with the car. Was original AMP retained or replaced? If it was retained, what device did they use to interface the new radio unit to the amp? does it have CAN BUS interface?
If it was replaced, did they terminate the CAN BUS chain?

 

Thanks so much for the replies! I have a good feeling you guys are right on the money with this. I know the installer charged me like 600.00 for the harness to connect to my stock Bose amplifier and speakers. I will call him on Monday and find out if he terminated the wire properly. Do you think he will charge me extra to put on this terminal connector?

 

If it was $600 it was probably something like this...https://navtv.com/products/NTV-KIT210/most-hur-997.html
In case of this unit, it connects to the can bus signal and you would not need any terminators.
In any case I would object if he tried to charge you to get it resolved.

If you take a look at this picture you will see a top plug with only 3 wires. Similar one would be on a carrera with wires being in slightly different places in the plug. Those wires are 12V positive and negative and CAN BUS signal. That's were the $600 unit he installed plugs in to (CAN BUS signal wire) or some sort of a signal terminator needs to be plugged in.
http://www.planet-9.com/gallery/files/3/DSC09895.JPG