Gearbox Failure & Error Messages on T6

[Bill Heath]

We had a breakdown on our new Autohaus Camelot Campervan in June of this year where we lost drive from the automatic DSG gearbox, the engine started to rev high and I thought I had knocked the gearstick out of the drive position, when I moved the gearstick to any position there was no drive at all.

The message came up on the screen "Front Driver Assist Failure" and all the doors unlocked, at the time we were in a very bad position on a bad bend coming up out of Glencoe, how we did not get wiped out was a miracle.

We had the van for only 7 weeks and only 1900 miles on the clock, our first adventure in the new van. I tried over the next hour to get the drive back but to no avail and had to wait 90 minutes for the breakdown truck to pull us around the corner to a safe position. After the 90 minutes when we started it up the drive was back but an error message appeared "ACC Fault".

We are trying to establish what triggered these messages and why the failure was caused... after three months at Volkswagen York & Bridgewater (and us without the vehicle) they have not been able to replicate the problem or give any answers other than it "May" have been a loose wiring loom connection.


The questions asked to VW when they say it "May" have been a faulty connection was:

1. What is the connection to having a faulty terminal on the vehicle linked to stopping the automatic gearbox functioning in any position (S D N R)?

2. What functional errors on the vehicle would trigger this message “FRONT DRIVER ASSIST FAILURE” to be displayed?

3. What functional errors on the vehicle would trigger the doors to automatically unlock?
90 minutes later the automatic gearbox would function correctly but a message appeared “ACC FAULT”

4. What is the connection to having a faulty terminal on the vehicle linked to the error message “ACC FAULT”?

5. What functional errors on the vehicle would trigger this message “ACC FAULT” to be displayed?

Volkswagen must have a set of parameters for the vehicle management: i.e. If the headlight bulb fails… then switch on a message on the dashboard “Bulb failure”

Answers to the above would give a better understanding of what happened and confidence that we could accept the vehicle back, as Volkswagen have had the vehicle for 3 months now and have not come up with a definitive answer, other than it “may" have been a faulty connection. There has got to be an explanation to the link.

Has anyone else experienced anything similar or could give me a link to where I could get a downloadable manual explain the messages that come up on the display.. I have asked VW technical for this and so far no reply on the answers.

 

[Loz]

Both the ACC fault and the front assist fault can be linked to the radar unit in your front grill.
This fault alone probably wouldn't cause the gearbox to panic in this way.
However, a temporary power interruption or a disconnection in the Can bus circuits could cause them both to fail at the same time.
Something as simple as a fuse, in fact there is a 5 amp fuse in the fuse box next to the battery which you can cause a similar fault so it could be something as simple as a fuse with a dry joint could cause this while you're driving along if you're going over bumps
If it were me I would take out and reseat all the fuses next the battery especially the 5 amp fuse which I sometimes use as a temporary way of disabling the vehicle.

 

[Pauly]

As above the first thing thats comes to mind is the front radar sensor as this is utilised by both systems to operate/function.
The only thing i can add is that the front radar has an isolating relay that disconnects the wiring to the front radar sensor when the van is not in use so you dont have active canbus connections on the exterior of the vehicle which could be accessible to a potential thief, a faulty relay would do the same thing to the radar sensor as a loss of power ?

 

[Bill Heath]

Both the ACC fault and the front assist fault can be linked to the radar unit in your front grill.
This fault alone probably wouldn't cause the gearbox to panic in this way.
However, a temporary power interruption or a disconnection in the Can bus (it's not a bus it's a van) circuits could cause them both to fail at the same time.
Something as simple as a fuse, in fact there is a 5 amp fuse in the fuse box next to the battery which you can cause a similar fault so it could be something as simple as a fuse with a dry joint could cause this while you're driving along if you're going over bumps
If it were me I would take out and reseat all the fuses next the battery especially the 5 amp fuse which I sometimes use as a temporary way of disabling the vehicle.

Thank you Loz & Pauly for taking the time to reply and explain about the connections, I understand that a faulty connect could cause an error message but my biggest concern is with the gear failure. VW have gone over all the connections and say they are all ok, a loose connection is a nightmare to find and simply disconnecting and connecting can rectify. But how would that cause a gear drive failure?

 

[Loz]

Thank you Loz & Pauly for taking the time to reply and explain about the connections, I understand that a faulty connect could cause an error message but my biggest concern is with the gear failure. VW have gone over all the connections and say they are all ok, a loose connection is a nightmare to find and simply disconnecting and connecting can rectify. But how would that cause a gear drive failure?

The DSG is two manual gearbox rails with 2 clutches that are automatically operated, during a failure, it may open the clutch and simply coast.

 

[HootingOwl]

Time to reject the van and get all your loot back. You have not had the use of your camper over the summer. VW are clueless and you could have been seriously injured.
The sorry fact is that VW dealers have lots of training on how to upsell service items, but are completely lacking in how to understand and interpret data from the diagnostic tools. If there isn't a fault code stored, then they assume there is no fault.

 

[ski99]

Aaah, finally, somebody who's having a similar issue to me!!

I've got a 150 DSG, and at just over 5k miles, I accelerated from a set of lights, just having left a motorway after a 5 hour drive into the middle of France, and our gearbox did a very similar thing. The 'box moved to neutral, and the ACC/ABS/Airbag lights all came on with associated beeps, but the stick was still in "D". Luckily I was able to coast into a bay and stop with being rear-ended, but it was a scary experience. It happened in a very violent way, and my first though was that a driveshaft had detached. I turned it off, then started again, and the drive had been restored, but the airbag light stayed on. I chose to drive to a safer place, but when accelerating it happened again. As a fairly tech' minded ex VW employee, my thoughts were that a sensor had failed or come loose as it didn't feel mechanical, apart from the forced change from "D" to "N". I don't have ACC, but it sounds like a similar failure.

I managed to get to an empty carpark, and had a good look around underneath, and everything appeared OK, so did some testing to see what was happening. I worked out that anything more than very, very light throttle application caused it to fail, but it would drive to traffic speeds if treated cautiously. I went to a retailer nearby by they weren't CV so wouldn't touch it. We made a choice to carry on to our destination rather than wait for Euro' Cover at this stage (read too many negative threads about UK owners experiences when using it) and had a decent break. Coming back we manage to get home without a re-occurance too, but I booked it into our retailer before we came home.

The retailers initial "fix" was that it needed a new Body Control Module (BCM), so this was ordered, fitted, road tested and then returned to me. 2 days, and c.150 miles later, exactly the same fault accelerating onto a dual carriageway. I moved the stick to "N" and managed (DSG Coast can be a wonderful thing!) to the next junction, and away from danger. Turned it off & on, airbag light stayed on again, did a quick test, and drove home. This time I got the AA to take it back to the retailer, and their resolution, as advised by the Tech' Centre at Wymbush was to replace the ECU. I told them that I would rather they did an extended road test for a few days instead of just saying it was fixed, and after 2 days it failed on their master tech'. He then looked around everywhere as Wymbush couldn't explain what the faults were, and when removing the plug on top of the gearbox, the Earth wire hadn't been crimped, and came away in his hand. He connected it properly, and I'm awaiting the outcome of this fix to see if it really was the issue. It's supposedly coming back to me this week.

It's been away from me for over 50 days so far in total. VWCW Customer Service, whilst being attentive and very good at keeping me informed will not accept any liability for the fault, won't enter into a discussion about me rejecting the vehicle as it was a used ex-demo, so the conversation has to go through the retailer apparently. The retailer has been fairly good, kept me mobile, but I have told them if the failure re-occurs then they need to provide a replacement as it's not fit for purpose, and potentially lethal and unroadworthy.


Sorry, wordy, but it may help Bill?

 

[VWDrooper]

Properly no help but this has got me wondering, took my T6 Ocean DSG to local dealership to sort out a high beam fault and look into fault code 10650 which is transmission related according to code reader but manufacturer specific so no further detail available to a mere mortal like me.

The dealership could not do anything on the fault code as is was not a static problem by which they mean no warning lights had been triggered so no further information was available, when questioned on it further they told me it was selector related but had no idea what would have caused it. Now it's possible the code was triggered by me accidentally knocking the selector into neutral, code was cleared and did not reappear on the 1hr trip home, I will of course be checking to see if it does on a regular basis.

Now the other thing that happened whilst at the dealership was a Service Action, number 34i3 which is to replace/relocate a wire which rubs on the transmission and therefore frays, don't know what wire it is or what happens when it frays and then shorts on the transmission unfortunately but could this be related ???? Who knows but it's got me thinking

 

[Bill Heath]

Aaah, finally, somebody who's having a similar issue to me!!

I've got a 150 DSG, and at just over 5k miles, I accelerated from a set of lights, just having left a motorway after a 5 hour drive into the middle of France, and our gearbox did a very similar thing. The 'box moved to neutral, and the ACC/ABS/Airbag lights all came on with associated beeps, but the stick was still in "D". Luckily I was able to coast into a bay and stop with being rear-ended, but it was a scary experience. It happened in a very violent way, and my first though was that a driveshaft had detached. I turned it off, then started again, and the drive had been restored, but the airbag light stayed on. I chose to drive to a safer place, but when accelerating it happened again. As a fairly tech' minded ex VW employee, my thoughts were that a sensor had failed or come loose as it didn't feel mechanical, apart from the forced change from "D" to "N". I don't have ACC, but it sounds like a similar failure.

I managed to get to an empty carpark, and had a good look around underneath, and everything appeared OK, so did some testing to see what was happening. I worked out that anything more than very, very light throttle application caused it to fail, but it would drive to traffic speeds if treated cautiously. I went to a retailer nearby by they weren't CV so wouldn't touch it. We made a choice to carry on to our destination rather than wait for Euro' Cover at this stage (read too many negative threads about UK owners experiences when using it) and had a decent break. Coming back we manage to get home without a re-occurance too, but I booked it into our retailer before we came home.

The retailers initial "fix" was that it needed a new Body Control Module (BCM), so this was ordered, fitted, road tested and then returned to me. 2 days, and c.150 miles later, exactly the same fault accelerating onto a dual carriageway. I moved the stick to "N" and managed (DSG Coast can be a wonderful thing!) to the next junction, and away from danger. Turned it off & on, airbag light stayed on again, did a quick test, and drove home. This time I got the AA to take it back to the retailer, and their resolution, as advised by the Tech' Centre at Wymbush was to replace the ECU. I told them that I would rather they did an extended road test for a few days instead of just saying it was fixed, and after 2 days it failed on their master tech'. He then looked around everywhere as Wymbush couldn't explain what the faults were, and when removing the plug on top of the gearbox, the Earth wire hadn't been crimped, and came away in his hand. He connected it properly, and I'm awaiting the outcome of this fix to see if it really was the issue. It's supposedly coming back to me this week.

It's been away from me for over 50 days so far in total. VWCW Customer Service, whilst being attentive and very good at keeping me informed will not accept any liability for the fault, won't enter into a discussion about me rejecting the vehicle as it was a used ex-demo, so the conversation has to go through the retailer apparently. The retailer has been fairly good, kept me mobile, but I have told them if the failure re-occurs then they need to provide a replacement as it's not fit for purpose, and potentially lethal and unroadworthy.


Sorry, wordy, but it may help Bill?

I am pleased in a funny sort of way that someone else is experiencing this problem and thank you for your time in explaining your situation. We have also asked for a full refund being as we only had it for 7 weeks and covered 1900 miles, likewise we have said its not fit for purpose, so far the dealer is saying no! We wont stop here we are pursuing it further. I have prepared a full history PDF with photos so if anyone wants a copy please email me bill@lawnswood.co.uk.

 

[Bill Heath]

Properly no help but this has got me wondering, took my T6 Ocean DSG to local dealership to sort out a high beam fault and look into fault code 10650 which is transmission related according to code reader but manufacturer specific so no further detail available to a mere mortal like me.

The dealership could not do anything on the fault code as is was not a static problem by which they mean no warning lights had been triggered so no further information was available, when questioned on it further they told me it was selector related but had no idea what would have caused it. Now it's possible the code was triggered by me accidentally knocking the selector into neutral, code was cleared and did not reappear on the 1hr trip home, I will of course be checking to see if it does on a regular basis.

Now the other thing that happened whilst at the dealership was a Service Action, number 34i3 which is to replace/relocate a wire which rubs on the transmission and therefore frays, don't know what wire it is or what happens when it frays and then shorts on the transmission unfortunately but could this be related ???? Who knows but it's got me thinking

Hi VW Drooper, thanks for your story on your Ocean DSG, we were told about the same recall on the wiring loom last week but found it hard to see how a fault would arise in seven weeks from new. They have since checked the wiring and fittings and have said that it had no connection with our problem. They have still not offered an explanation as to what would trigger a failure of the drive... They just say no fault could be found!!

 

[PukkaT6]

This seems to be on vans around my age so will keep an eye out.

The worst thing I have done with my DSG was put it in park before I had fully stopped, it did a little skid - I needed the toilet real bad.

 

[Chrisfraser05]

This seems to be on vans around my age so will keep an eye out.

The worst thing I have done with my DSG was put it in park before I had fully stopped, it did a little skid - I needed the toilet real bad.

a little skid, the van or you?

 

[ski99]

... an update, slightly belated though!

The loose wire was traced to the connector at the top of the gearbox, which according to the tech' hadn't been crimped into place. The failure hasn't re-occurred since, although I've only had it back 2 weeks, and it hasn't covered the mileage I'd usually do in it. It does feel that they've resolved the issue, but it'll take a while before my faith has been restored in it.

To be fair, the retailer has been great throughout, VWCVCS have been OK, but their reluctance to accept any liability, or even discuss the poor build quality has been very disappointing.

 

[Bill Heath]

Hi SK, thanks for your update, interesting that you have some sort of answer to the problem. VW have had our van now for Nearly 4 Months now and all they come up with is that there is no fault, they have not answered our questions: 1: what would make the gearbox go into neutral 2: what would make the error appear on screen "Front Driver Assist Failure" 3: what would trigger the doors to automatically open and 4: what would trigger the message ACC fault? They just say take it back and see if it happens again which is not acceptable. They have road tested it for some 700 miles now. As far as we are concerned if they cannot explain why it happened then the fault could still be there and it is a potential death trap. Thanks Bill

 

[Bill Heath]

After 19 weeks without our Autohaus Camelot Campervan we still have not got any answers from Volkswagen on why the gearbox would fail by going into neutral, at the same time an error message appears on the screen "Front Driver Assist Failure" followed by the doors automatically unlocking.

The garage we took it to wiped out all the recorded error codes and did not record them but were hoping that they would re-appear. Consequently they could not diagnose the failure. Now they are saying that unless an error code appears they cannot do anything! They have carried out over 750 miles of testing and say that everything is ok and we should take it back! But cannot answer the questions as to why those three items failed at one go.

Can anyone help us with finding out what error/fault codes would be associated with any of the above scenarios.

 

[Pauly]

Not sure it's possible, fault codes are vast and diverse and sometimes irrelevant/misleading

 

[HootingOwl]

Reject it. Sounds like a deathtrap

 

[ski99]

Bill, the way that these are designed means that unfortunately any one fault can trigger a series of faults in parts
or sensors which are totally unrelated to the actual part that has failed. That's what happened with mine, and I
do think that if I had ACC on mine, it would've flagged at a fault too. When the AA came to look at mine after the
second failure, the computer had 38 different faults, from airbags, ABS, Traction Control, Cruise Control, speed
sensors etc.

I've had it back for almost 2 months, and it does appear that the loose earth was the root cause of the issue.
Admittedly, it's only done a fraction of the mileage it would've normally done in that time as I've been given use
of another vehicle through work, but I've driven it in the same manner as when it failed previously, and so far, so
good.

You haven't mentioned whether you informed your retailer of the fault with mine, and also whether it's failed again
since they've completed the 750 miles of testing, or if you've taken it back, but it's entirely possible that nothing, other
than a poorly connected wire has failed, and that could've triggered the fault codes.