Can Bus or ABS Controller - 986 Forum - The Community for Porsche Boxster & Cayman Owners

I went to a recommended Porsche tech center and I got the younger tech (no one else was there when I arrived). I don't know if I learned as much as I could have otherwise. I bought a 2.7 (2001 year) and have been working through several little problems, but one of the big remaining problems is both speedometers, the odometer and the spoiler do not work. The young tech hooked it up to his "better than Durametric" scanner and reset the codes but told me they would probably come back. I asked him how to find the speedometer problem and he said it would cost him more money (time) to find it than I would pay him. He then told me (rightly) that I still needed to fix it. He said it could be the speed sensors (but he didn't seem to know which one feeds the speedos (or maybe I don't understand and all of them feed the speedos). He said it could be the ABS controller (but said it was expensive) (My gut tells me this is the problem as I checked continuity on the sensors.) He said there was also an indication of a "Can Bus" error even the Air Conditioner not getting info to/from the Can Bus. He said it could be the entire instrument cluster (everything else seems to be working properly). On the way home the Check Engine Light did come back on like he predicted. He was a nice guy and helpful (to a point) so I don't want to sound too sour about still leaving me with a lingering question. ( I drove it almost 1.5 hours to get this figured out but came home with it still there.) Any ideas or recommendations are welcome!!!

Quotes source post: 371062

If he did that, then don't expect him to properly troubleshoot your problem -- pulling the codes is the first step of the diagnostics and he shouldn't have reset them. Now you don't have the codes to post here to hopefully receive help from the forum community. Regards, paul...

All of the speed sensors feed in to the ABS controller, which does something with the signals to get vehicle speed, which it in turn feeds out to the cluster. without the signal from the ABS unit, none of the things you have mentioned will work. However, if the ABS unit wasn't working or not receiving speed signals from the wheels, it would throw an ABS error lamp, not a check engine lamp. Looking at the 2001 schematic, it seems that the ABS feeds in to the CANbus, from there to the PSM and out to the Cluster. Check Fuse B8 - if that is good, I'm thinking you have some odd CANbus fault. If you can get it read again and post the codes, it will help a lot.

very informative! There is still a ABS light and a brake fluid light showing on the dash. Does that tell you more?

Sounds like you need whats "only as good as a Durametric" scan tool to solve your issue. I bet the strategy behind charging you more than you will pay, was to sublet your car out to someone with the tools & experience to fix it & charge you a % above their costs.

I have a 2004 Boxster base model that I am converting to electric and need to understand/get all info I can on the CAN Bus. Since the engine will be missing once I take it out and all parts related to it, like the fuel system, exhaust system (!) I will need to fool the CAN bus to make some of the basic things work and also tap the CAN bus for signals. Based on the below thread, I can assume that my 2004 does use CAN bus. What systems (arduino based or otherwise) have people used to hack the CAN bus on the Boxtser? Any and all info you can provide will be appreciated!