DSG DQ381 woes on a 2.0 tsi 190

[Steve Caney]

This is a long story so bear with me.

I had my DSG serviced 2 years ago and everything was ok until last year when the DSG went into emergency mode with only gears R,2,4,6 available. I stopped soon after and switched the car off for a while, and restarted and the error went.

However in Feb I had 2 more failures same as above on a long drive. (Both there and back) and it seemed the error was occurring when the gearbox was warm/hot.
The error stored on the ecu was P173500.

I spoke to a local independant garage and their mechanic had seen this error a couple of times before and had done an experimental fix and had cured faults.

I researched this and basically he was going to do this....

Much better than sending the mechatronics away for repair, so last Friday I had the repair done.

Results... I went for a long drive on Sat and Sunday, no problems or faults reported.

There is one issue though that I think needs to be highlighted.
On the invoice from the original garage who did the DSG service, I noticed that they only charged me for 5 litres of oil.
This garage charged me for 7 litres, and I am wondering if the original garage did not carry out the DSG service correctly and hence underfilled it with oil.

Which is why maybe it was overheating and the error came up in the first place???

 

[nd-photo.nl]

The first question I had was: what does "service" entails when you went to the original garage?

I don't know if you are aware of it, but this is the procedure:

When I serviced my DQ250, I needed to pump in 6 liters of oil and then drain it out. 5 Liters is probably not enough....

 

[SuperV8]

This happened with a work colleagues 2020+ Passat TDI DSG.
He also determined one of the temp sensors in the mechatronic unit had failed. Whilst he was in there he changed both.
It's not a fault of actual over heating - just a failed temp sensor.
The refill qty is 6-6.5L - I would guess the first garage just let you off 1L. You need to refill using a VCI to set the correct level at the correct temp as is common with many auto gearboxes.