Hi, I have finally located a wiring fault in o5 s type that has been causing major issues resulting in p1643 can bus communication fault that has gone from intermittent to wont start back to almost solved! Started with epb stuck on one morning and then developed into a non start situation. After plundering along doing various tests and replacements have narrowed it down to abs/epb wiring going into the body under the rear axle. My question is can i access this wiring from under the rear seat base? Any help would be appreciated and i have a post already covering this issue since the beginning and would be hopeful of providing a resolve to conclude it rather than leaving it open ended. Kindest regards

 

Can't help with any specifics of the harness location, but it is easy to remove the base of the rear seat and find out. Two latches are located under the lip at the front. IIRC, they slide to the side and then you just lift up. Once the front is free, slide the seat bottom forward to release the rear edge.

 

Cheers! yes its ok i found what i needed but looking like my problem possibly between the epb and the module

 

hey andy! Could you please tell me the conclusion on this one too? Many thanks

 

Hi eldariusvargas
This was one of the many false leads i had whilst trying to locate the cause of the p1643 code which translates to non communication on the can bus wire's between the tcm and pcm.
If you are having a similar problem then i am afraid unless you have done the usual checks and fault finding in the workshop manual my fix may not be the answer!

Ultimately my cause was nothing to do with can bus so although putting me in the vicinity of the problem the fault code was of little clue as to the real issue.
These cars are old enough and prone to suffering broken cables within the wiring harness and if your problem is intermittent it dosnt make it any easier to find.
If you would like to give a little background info on your car's problem i.e when and how the problem persists and how frequent then it will give something to go on and may be able to rule out some of the tedious stuff.

I will assume you have done battery checks and rear wheel sensors as these are common issues that can cause problems although if your red indicator light is not illuminating on the transmission this leads to fuse checks before messing around pulling stuff apart.

 

hey thanks for the quick reply

i swapped my engine,and even tho i paid attention and took care of everything, i ve encountered this p1643 issue as well.
it starts in the mornings, runs 2 km then it starts the tran limp mode, j gate red lights turn off.
same as what happened to you.
did you solve yours?
also a bad wiring happened to the upsetram bank2 sensor. Sensor is 100% working fine

 

As he posted, he ran separate wires.

 

Andy asked me about some intel on my problem, and so i told him.

Wires... 🤣wires can be found anywhere under the hood, i am talking to andy in hopes that he can point me to the ones that he found faulty, and how he ran the new ones. Someone told me its the red-brown (+) one?
If so, where did you connect it? Right at the sleeve connector?

 

Good luck. Others will perhaps want to know in the future so posting it on here can help.

 

hey! Im back. Ive posted a new thread as i went in depth and found other issues as well, but i will post here a quick TCM cables description for those interested, since ive asked for them too.

10 cables in my case (2003, 3.0v6 zf6hp):
2 black grounds they bolt on the body by the wheel arch
2 pairs of green yellow canbus for ecu and jgate/dsc etc
2 signal wires orange & green red
1 Live positive (always active)- thick brown (from front fusebox)
1 ignition positive - green orange ( from primary fusebox)

my ignition positive cable measures 11.8v because of a voltage draw in a circuit powered from the same feed.
ive detailed it in my thread.
this is what andy might have experienced too..

thanks a lot, and i wait for you guys to give your opinion on my issue