My Polo GT TSI refuses to crank, VW says its a DSG failure. Now what?

I installed a new battery last week, so it's not a battery issue.

BHPian nova9 recently shared this with other enthusiasts.

I have a 2016 Polo Gt TSI which has run about 42,000 kms.

Yesterday when I tried to start the car, the starter didn't crank.

All lights on the console would come on and then turn off like how it does normally.

No noise from the starter at all.

I installed a new battery last week, so it's not a battery issue. (I would have heard that clicking sound if it was a battery issue)

Since VW couldn't collect the car on the same day, I contacted my local mechanic, who did some workaround and connected a wire which i presume was to the starter and then told me that if the "P" in the gearbox indicator was blinking then the car wont start and the work around was to keep the car in "P", turn the ignition on and the open the bonnet and touch that wire to one of the batteries terminals. This cranks the engine and after that the blinking "P" goes away

So after that the car drives like it normally does. No gear shifting issues no knocking, no jerky shift. In short the gearbox works fine.

Today I drove it to VW after using that hack, and the SA calls back after a few hours saying its a mechatronic issue.

He still hasnt given me a quote but i bet its going to cost me my left kidney

So the question to all experts is, are they taking me for a ride?

If the DSG is faulty then shouldn't I get gear shift issues?

And have you seen a case when a so called DSG failure prevents the car from starting?

Thanks

Here's what BHPian headers had to say on the matter:

Hi, it appears to be a sensor issue. If it is a DSG issue, you will not be able to shift smoothly and there will be jerkiness in shifting between first and reverse gears.

Kindly witness the scan [when they run it] and you will get a clear picture of the issue.

A new battery could also be the culprit, please check the battery threshold voltage.

Goodluck

Here's what BHPian JoshMachine had to say on the matter:

First up, hope the new battery has the same rating as required for the Polo? Anything lesser and the starter won't have enough voltage to power up.

As for the possibility of the DSG failure tied to the car not starting, that's a rare occurrence to me atleast. The linkage I can possibly derive is the "selector level assembly" failure if it is really the root cause. The primary function of the assembly is related to the Hall Sensors of the selector lever which register the position and make it available to the mechatronic unit via the CAN bus. If the control unit detects no selector lever position due to a malfunction of the sensors or the solenoid, then the starter mechanism could assume (via some signal) that the clutches are actually opened, and hence may not complete the cranking operation.

BHPian nova9 shared the following update:

If the car is not started using the workaround, I mentioned earlier, the scanner isn't able to detect the mechatronic unit (TCM)

When I start the car using the work around the unit gets detected.

Screen shot of the error code below

They still insist its a mechatronic failure.

Does the above shed any clarity?

Thanks

Here's what BHPian Jeroen had to say on the matter:

All I see is a U010100 error code. That is an network error code, meaning the TCM has lost control with the rest of the network.

This is an electronic network fault and nothing to do with the DSG as such.

I would make sure the battery is ok. Test for capacity, not just voltage! Check the battery connectors, take them off, clean them and reconnect. Check the mass strap. Check all connector especially those of the ECU and TCM and all CAN related connector. Pull them apart and re-insert. Check all wiring for chaffing, rat bites and so. If you’re lucky, that might fix the problem.

However, if it doesn’t it is bad news: it will require a lot of experience and knowledge to trouble shoot this code.

Video

Just google OBD U0101 and you will see various pages on this very code. It is a generic code, available on many different brands. Each implementation might be slightly different, but in all cases it means there is no communication with the TCM. Which usually means the CAN is somehow down/not working.

Ask your technician, the mechantronic and the TCM are not one and the same.

Good luck

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