Passat B6 Steering Torque Sensor Implausible Value

[Pharlapdog]

Hi Guys,

Sorry for the long post but I thought I'd better include the history in case it is relevant.

Back in May 2023 I had the NSF driveshaft replaced by a local garage. I have not used the car much since then but on Sunday I lost all drive going round a roundabout in Farnborough after hearing strange noises coming from the NSF. On inspection, the bolts holding the driveshaft to the engine/gearbox were all loose and one had fallen out entirely.
I was able to inspect both driveshafts by starting the car up and applying full lock left and right.


I had the car recovered to the garage that had done the repair. The recovery vehicle used a winch to put the car onto the flat bed using hooks underneath the car not the towing hook. I do not believe that the driver started the engine.


The garage agreed to repair the car under warranty which they did but could not hand the car back as the power steering was now faulty. The error codes say something like 'implausible torque sensor reading' and the power steering is very heavy, i.e. no assistance. The error code can be cleared but returns every time the car is started. The garage have tried to fix the problem and say they have checked the obvious things like fuses & wiring but are unable to fix the problem.


They claim that the power steering fault was present when the car was delivered to them. Is it possible that winching the car onto the flatbed truck has broken the torque sensor or can the steering rack be recoded to work properly?

I have a VCDS but can't scan the car at the moment as its still with the garage.

Kind regards,

Tim.

[Crasher]

Don’t worry about the long post, I am a master of such. All the bolts being loose and one missing won’t lose drive, the shaft has to disconnect completely so the differential in the box diverts all drive to the disconnected flange.

I can’t see any of what has happened causing the torque sensor inside the steering gear (it’s proper name, not rack) to fail unless that inner joint fell off and gave the steering gear a good ******** BUT this happened to us a few weeks ago in a very similar situation with a Leon 2 after we had done a new outer CV boot and lots (over £1k) of other MOT work. The day after, the steering assistance failed with the same code according to the description (I can get the code tomorrow at work and we can compare results if you pop over there) but there was no correlation between the work and failure, just unfortunate coincidence as it is a known weakness, so much so that we have been unable to buy new or exchange steering gears for over a year now from TPS as they have been on permanent backorder.

The point I have noticed with this failure mode (they also fail the MOT due to wear and rattling) is that the assistance is more than lost, it actually feels as though the steering is fighting you, if you turn off the engine, the steering actually feels lighter. In the unit we were using, cars have to be reversed in up a slope at an angle with lots of steering to and fro, both the technician and my business partner ended up at the osteopaths a couple of times afterwards with shoulder injuries.


https://digital-assets.tecalliance.services/images/3200/fc63434b93550689c19af833564f403fb439ec76.jpg?ver=3 .90.0.337840e152

The same part number 1K2 423 055 K or KX exchange is used right across the VAG range of PQ35 (Golf 5, Leon 2 etc) and PQ46 (Passat 3C, Superb 2 etc) and as we did three times last year and once so far this year, we ordered a Bosch K S01 000 747 exchange unit. The steering gear for right hand drive is made by ZF Lenksystem which is a Bosch/ZF joint venture due to some EU competition rules and this arrived in a fortnight as Bosch UK will not bring them in on a fast order due to their size so they have to come on an agents stock order. Your car as did the Leon, will have a Generation 2 gear so the VAG Gen 3 conversion wiring harness 1K2 971 111 AJ at £ 163.80 will be required. I can’t remember who much we charged for the gear but it was about the same as genuine exchange from TPS at £1524 retail inc. Add to that two track rod boots (ideally two track rod kits) and a significant pile of genuine VAG fasteners which MUST be used, a not inconsiderable amount of labour plus final alignment and you have an easy £2.5k bill.

[Pharlapdog]

I can’t see any of what has happened causing the torque sensor inside the steering gear (it’s proper name, not rack) to fail unless that inner joint fell off and gave the steering gear a good ********
Well it did not fall off as far as I know as the inner CV joint was still attached to the diff when I pulled up. Its probably the garage not using the proper tools to get the track rod end off when replacing the driveshaft.


The same part number 1K2 423 055 K or KX exchange is used right across the VAG range of PQ35 (Golf 5, Leon 2 etc) and PQ46 (Passat 3C, Superb 2 etc) and as we did three times last year and once so far this year, we ordered a Bosch K S01 000 747 exchange unit. The steering gear for right hand drive is made by ZF Lenksystem which is a Bosch/ZF joint venture due to some EU competition rules and this arrived in a fortnight as Bosch UK will not bring them in on a fast order due to their size so they have to come on an agents stock order. Your car as did the Leon, will have a Generation 2 gear so the VAG Gen 3 conversion wiring harness 1K2 971 111 AJ at £ 163.80 will be required. I can’t remember who much we charged for the gear but it was about the same as genuine exchange from TPS at £1524 retail inc. Add to that two track rod boots (ideally two track rod kits) and a significant pile of genuine VAG fasteners which MUST be used, a not inconsiderable amount of labour plus final alignment and you have an easy £2.5k bill.

The car is only worth about £800 I'd say so a £2.5k bill sounds pretty terminal. I take it you would not recommend a second hand gen 2 gear off eBay? I'm not sure I'm up to lowering the sub frame to fit it. I liked to do my own maintenance in the past but I'm 67 this year and getting too old to be crawling about under the car for hours.
Interesting point about the steering fighting you. Would turning Terminal 15 off help (if that is possible?) or are there other systems attached which would fail too?

Many thanks for your insights.

[Crasher]

I am just 60 and there is no way I would do this on the deck, it would finish my back and knees for good! No we won't use second hand, I have in the past and bought twice so virtually anything second hand is banned here now. I HAD to buy a second hand ECU for a 2009 A4 TDI as new was £2200 and special order from Germany plus the customer would not do it and add to that I wasn't 101% sure of my diagnosis. After four used and tested ECU's I got one that worked and it took 6 months to sort it out.