Replaced Radio Now Workshop Fault - Brake Proportioning - Oil Pressure Too Low

[Nick Radloff]

Hello. This is my first time posting as this is my first issue with my 2006 Cayenne S and this is also my first Porsche. The vehicle had an aftermarket radio in it when I purchased it and I changed that radio for another one that supported Apple CarPlay. both units are made by pioneer and after looking at the backs of them it appears to be plug and play. I changed everything out and fired it up and everything was great. No issues or errors and the sound worked fine and calls worked fine. The previous installer used only twisted ends and electrical tape to secure the wiring so I took the wiring apart and used wire nuts to make sure nothing came apart while it was being installed and for longevity. After starting the car back up, I received a brake proportioning fault and an oil pressure fault and it told me workshop fault as well. I pulled fuse 40 as I heard it resets the system and plugged it back in. The brake proportioning fault is gone but the oil pressure fault remains. I double checked my wiring work to make sure that I was not missing anything and nothing had come back apart. Everything is indeed attached and plugged in. 

 

Now that I have finished my long-winded story, was this fault caused because I knocked something loose or because I left the fiber optic cabling unplugged for too long. I noticed that there was a red light coming from the input and of the fiber optic cabling a couple of times while I was rewiring it. Do I just need to reset this system using a better method or do you think something is wrong with it? 

 

Any help would be appreciated and I intend on donating to this forum and website as it seems to be a true source of knowledge and help for the DIY Porsche enthusiast. Thank you in advance and I look forward to your responses.

[Nick Radloff]

I have confirmed that the speedometer and the tack are not working as well. something tells me I may have knocked something loose but I don't know enough about Porsche systems and the fiber optics hub and module to know otherwise..

[JFP in PA]

OK, first of all, either twisting wires together and wrapping them with tape, or using wire nuts is totally unacceptable for automotive applications.  Both are pathways to shorts and even fires.  Wires should be reconnected with crimp connectors at a minimum, with soldering them and then using heat shrink tubing to cover the soldered joints the actual preferred method.

 

Most likely, in the process of doing this swap, you disturbed something, but exactly what is hard to say, particularly as the previous owner used the twisted wire and tape wrap method of connecting things.  It is entirely possible that you may have pulled another such "MacGyver" like repair loose that is not related to the radio swap. 

 

Probably the best approach at this juncture is to get the vehicle scanned with a Porsche specific scan tool to see what the various communication modules are doing.

 

Good luck with this one.

[Nick Radloff]

I found it. It was another MacGuyver repair. Whoever had installed the radio had pulled the harness pretty hard and there was a bundle that was barely connected to a module. Needless to say, after plugging it in correctly and giving the bundle a little slack everything worked out just fine.

 

I wanted to use shrink butt splices for the connections but my local hardware stores have been out for a month or more due to Coronavirus supply chain interruptions. Hopefully, once this is all over, I can get the right stuff to complete the job but for now the nuts and 3M electrical tape will have to suffice.

[ViolinARC]

Welcome and nice find/fix. I have the '06 PorC too. Electrical gremlins are the toughest things to troubleshoot. Lucky it was just a loose connector. 

 

I have one word for you regarding the shrink butt splices...Amazon! Enjoy your ride! 

[ViolinARC]

HAHAHA. Just realized this was posted in 2020...DOH! Thread form the dead!