Wiring Diagram Help - what is VS?

[gary.warner]

I'm retrofitting a PCM1 to a MY2002 996TT and all is going well after a few hiccups (alarm going off at 5 in the morning - man, that thing is LOUD!) and am now at the stage where I can bring all the finer points of the wiring into the loom.

Every wire has a home but I want to make this as neat a patch as I can so want to trace where each of wires would normally be put when factory fitted. The only two that I can't trace are the reverse and the diagnostics. They are designated as connecting at:

Reverse: VS21[L6]

Diagnosis: VS90[O117]

All the other indicators are (semi)obvious so 'clust' is at the instrument cluster, 'CU Info' is the PCM main unit, 'SI' is the fuse... but what is the 'VS' part of VS21?

I've been taking pictures as I go along with this project so want to put a DIY up for all those other non-satnav 996 owners but I'd also like to make it as complete a project as I can.

Hope you can help

Edited December 18, 2005 by Gary Warner

[Loren]

The reverse signal should be under the left hand seat (on LHD cars not sure about RHD cars). Should be Black/Blue connections already there - just add you PCM1 reverse wire to them (solder or crimp).

What is the pin number on the PCM1 for Diagnosis? My schematic does not have anything labeled "Diagnosis".

[gary.warner]

What is the pin number on the PCM1 for Diagnosis? My schematic does not have anything labeled "Diagnosis".

On my schematic (and in the plug) it is on Plug II (Blue) on the main unit on pin 1 - Orange and Blue wire. It is also labelled as "Diagnostic K" on the cluster unit with the same wire colour. Diagrams are taken from the 99 Technical Repair Manual.

Thanks for the pointer on the reverse, the diagnosis I'll take from the cluster when I put the microphone in so I think I'm ready to go (again) - fitted the CD Changer this afternoon but too cold out there to go on any more and Christmas/Year End looms... Thanks again.

Edited December 18, 2005 by Gary Warner

[Loren]

Ah... sorry I missed it on my MY02 schematic.

That orange/blue wire gets connected to all the other orange/blue wires on the OBD II connector pin A3 (also know as K lead). That wire is needed for PST2 diagnosis so the PST2 knows the PCM1 controller is there and can be coded.

[gary.warner]

Loren, I have seen quotes from you in another forum (6 speed I think) where you state that PCM1 retrofit is not possible. I assume that you meant by simply adding a Porsche sub-loom?

Would you be interested in a DIY on this project - having looked high and low for info there seems to be plenty of people asking the retrofit question but no real answers?

I found PCM1 actually quite good - I know this contradicts a lot of other posts - and has the advantage of being audio, satnav and phone all in one - a situation I couldn't duplicate in the UK with a single double-din unit. Also, the navigation unit sits in the passenger compartment rather than taking up even more space in the tiny front luggage compartment on a TT or C4 where the after-market ones have to sit horizontally.

[Loren]

Gary,

Yes, there is no retrofit kit and the wiring must be added - so most shops won't even try. PCM2 (on MY02 and newer MOST system cars) is pretty straightforward and CoryNJ already wrote a DIY here on that.

Sure, if you have found an easier way to add PCM1 then please feel free to add it to the DIY Articles section here.

[targamanf]

Hello!

Has anyone of you the part numbers of the three connectors (blue, black and white) with 26 pins for the PCM System? I actually have taken BMW connectors (from a E36 speedometer) that fit but I want to have it like a factory install.

Hope someone could help

Manfred