Transporter T6 Boost Pressure Failure

[Deblank]

Good day all Transporter T6's
I had an unusual experience with my T6 Crew Bus and hoped to find some answers here.

On Thursday, while returning from West Coast to Durban, the T6 went into Limp Mode due to a Boost Pressure failure. The pressure sensor picked up something and limp mode activated. I was only 115kms from my start point and I was travelling an average of 120kph. Up the Piekenierskloof pass at moderate speed of 60/70 kph with moderate to light load. Then on the way down I cruised without acceleration - obviously - since pass is winding and steep. Then as I reached the bottom I noticed the glow plug warning signal was on and flashing and I had no power - just about idling. Luckily I could see a garage ahead and managed to limp in there.
I called VW roadside assistance and patched me into my regular dealer workshop. After some advise from them - switch off and switch on and then test. It seems the power was restored and the warning light had reset. On their advice I returned to West Coast and took vehicle to Rola Motors Vredenburg. The trip back was fine - just as if nothing had happened. They checked and reported that they had cleaned the sensor and that the vehicle was fine to take on the trip back to Durban.

I am not sure whether I should replace the sensor or not. If the sensor reports a problem, why must we blame the sensor? Its like shooting the messenger. It could be that the something else is failing and that the sensor merely picks it up.
What are your thoughts? Should I post this and ask opinion from some of the experts.

Thanks for any feedback.

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2016 Transporter T6 Crew Bus

[panic-mechanic]

The management stored the code and they obviously cleared it. Without knowing what the exact code was it is very hard to comment. So either it was an overboost or underboost. Without knowing which it was it's impossible to say what to fix or look at.

[Deblank]

Thanks for your response.
I decided to replace the sensor as a matter of safety on the long trip back to KZN

[Abnormal]

It may not be a failing sensor though, it may be the sensor picked up an actual condition.


Panic what should be checked if its underboost?

[panic-mechanic]

Vacuum control box for boost, actuator, boost pipe leak, stuck vanes on the turbo - can be a myriad of things. Hence why one should check what it complained about in the code and take it from there.

[Deblank]

Ok, so the problem happened again after replacing the sensor.
This time the car was lighter with only the driver. Going down hill on an off ramp - similar to going down hill on the pass without acceleration. Seems there is something common about down hills and no acceleration. This is also a response I got from 4x4community member who says same thing happened to him under similar conditions.
So it appears something goes wrong with the boost pressure when traveling down hill.

[dazza]

Ok, so the problem happened again after replacing the sensor.
This time the car was lighter with only the driver. Going down hill on an off ramp - similar to going down hill on the pass without acceleration. Seems there is something common about down hills and no acceleration. This is also a response I got from 4x4community member who says same thing happened to him under similar conditions.
So it appears something goes wrong with the boost pressure when traveling down hill.

That was me on 4X4 community. Definitely occurs only on a downhill at no or low throttle conditions which is weird