So sorry the Thread should have read ABS + TCS

Sorry, cant seem to change that.

 

Just my 10 cents, but so many 'No signal comms' errors across different modules starts to look like something catastrophic has happened to your CANbus control system (Battery connected wrong way or a battery charger has spiked modules?).

However, more than likely it is a common CAN controller or power supply/wiring/Fuse issue affecting all those CAN modules. I certainly wouldn't launch straight into an ABS module replacement.

Simple things first, remove and check every fuse one at a time so you don't get them mixed up (There are a lot!).

It doesn't surprise me that the average shop reading off those fault codes has a mindset that each fault is singular and unrelated to others. You really need somebody working on your car who understands CANbus systems and can do more than take the diagnostics codes at their face value.

If I was doing it I would first probe one of the 'faulty' modules to check if voltage levels on the CAN signal lines were correct and there were active data signals. You only need a module fault which grounds one or both CAN signal line and all the other modules will get screwed. Also, some important modules like the CAN Gateway operate as 'Masters'. My logical approach would be to check if there are voltage or signal activity problems on the interconnected CANbus lines, then disconnect modules one at a time and see if one module is causing the problem.

.....But then I am not a CANbus engineer or VW trained!

 

ABS & Tractions control plus more warning lights



Thanks for your interest and feedback. Having read some of these issues on this forum, I was hoping to get a response from you!

I can certainly start to look at the fuses and as you said pull them out and inspect one at a time.

Where on this car can I get to the CAN controller?

would I be able to do some measuring of the voltages using my hobby multimeter or does it need to be a fancy unit?

Incidentally, the second shop suggested that I raise this with VW Australia as they think there should not be so many issues and errors on a car that is 6 years old!

They were also surprised that the ABS controller has died at 55,000 Ks

They did try to clear the errors and retest and found the ABS fault again!!!
They told me that it was a hard code fault (whatever that means)???

I sent in to VW Australia a note about these issues yesterday and have not heard back anything!!!

I wonder if I should raise with them that this is not to be expected from a quality brand such as VW!

Kind regards,

 

BTW - the battery has not been changed or touched before all this started to happen!

BTW 2 - I did hit a large pothole (bloody Sydney roads) before all this started!!!

 

I had to replace my ABS module at 40K miles. Mine was the pressure sensor fault widely reported for all VAG cars. Unfortunately, you have to buy the complete ABS hardware because the pressure sensor is now pressed into the (expensive) fluid block.

Fault finding CANbus is tricky unless you have done a lot of background reading. It's like asking somebody to fix a PC. Well that's pretty much how complex these cars are now.

Hard code faults are usually the type of fault which shut off a module and it cannot be reset. This is common with air bag units because they don't want any Joe 'resetting' and leaving the unit still faulty. Same I guess with ABS units. Think of it as VW building in electronic 'self destruct' and forcing you to replace the module because the fault is not in the software.

With a system failure like yours you cannot hope to go to one controller and fix everything. It requires a methodical approach to testing with clues at each stage to work through. It can even come down to having known good modules as test units. The problem with the EOS is many modules are very specific to the EOS and you cannot just slap in Golf units, even if the part numbers 'look' similar.

By all means check each fuse with your meter, but after that I think you really do need a dealer with good knowledge of CANbus or an auto electrical specialist for VAG cars. If you think your fault list looks bad, it can get a lot worse if you cause accidental damage. If you haven't found out what voltages are present on auto CANbus and LINbus wires, you aren't even out of the starting gate.

I did notice roof module faults in your list, probably due to your other problems, so presumably as well as suspect brakes and steering, you have no roof operation? If you haven't got your own diagnostics you won't get very far either.

If I had such a random fault list as yours, I would be wondering if my car had suffered an emp pulse from a lightning strike.

 

Thanks again for you reply.

Firstly, my car as best as I know was not hit by lightning and I cant explain why the wiring would all of a sudden have shorts or issues.

do you mean all I can do is to check continuity with my meter for every fuse?

if I am reading you correctly, that is all I can do?

BTW how much did you have to form out for the ABS controller and hardware?

I dot think it is fair for customers who have bought what is sold as a quality German brand to pay for all this so soon. I have raised this with VW Australia but have not heard back at all.

I will go through the fuses and hope to find something.

thanks for your thoughts.

 

All new VAGs come with a 3 year factory warranty which covers just about everything. Used cars past this age are usually sold with the option of extended or insurance covered warranties. VW don't warranty for the life of a car and it is up to new owners to consider the complexity of modern cars, repair costs, their ability and skills to do work themselves and make a decision whether or not to buy add on warranty.

ABS modules in newer VAGs were being swapped out under dealer warranty with the same pressure sensor fault as mine. Since my EOS was 6 years old at the time and I never threw money at dealers for servicing, I had virtually no arm twist clout. However, a new ABS module popped up on Fleabay for £100 so I grabbed it. It might have been left over from a dealer warranty swap stock - I don't know. There are 8 brake lines to work with and bleed which you cannot do unless you have a m/c pressure bleeder and of course diagnostics is essential for code clearing, re-coding and checks.