Intermittant Limp mode stuck turbo actuator implausible signal

Westcoast888

Member
VIP Member
T6 Pro
Hi
Long time lurker here and now a new member because I had to reregister an account.

Hoping that someone can shed some light before delving further or taking the van to the main dealer or specialist.

Was driving the van last week and when I put my foot down to overtake it kind of stumbled and then went into limp mode (flashing coil) and im guessing the turbos are switched off as there was a lot less power than normal. I pulled up as soon as I could, switched off and on again and the van was fine again. a few miles down the road and the same thing again. I jumped in the van the next day and it drove fine. I've noticed that the battery seems a bit week so measured the voltage at the battery and its 12.2v, 11.6v with then ignition on.
ABS @ tyre pressure warning lights have been coming on recently as well but clear once I've driven 100yds or so. I've ordered a new AGM battery which should be here tomorrow so I can fit that and check voltage again.

I also plugged in my code reader and had a load of codes pop up. most seem to be connected with the knackered battery. I have recorded the codes in case they are needed.
I cleared the codes and then went for another drive and the van drove good for a few miles with various throttle positions etc but then went back into limp mode. I plugged code reader in and had 16408 Actuator module for turbocharger 1: Stuck P00AF_00 [100] Implausable signal. Cleared the code and drove home. I have read through various threads on here but I can't seem to find anything similar as most seem to be that the turbo is blown and im pretty sure mine are ok. well im hoping they are, but with my luck at the moment im maybe heading towards a sky high repair bill!

Im pretty handy with the spanners and I have a 2 post lift at home so was hoping maybe someone could point me in the right direction

2018 bitdi 2.0tdi 204 manual

Bought from new and currently has 38k miles. It does sit for a couple of weeks at a time as I have a works van

Many thanks for taking the time to read
Jay
 
Sort the battery issues out first, then you can see if there are any other real issues. Dodgy battery parked up for a couple of weeks won’t go well.
 
Ok so some further developments. I replaced the battery with a like for like AGM type. I reset the codes and went for a drive. all was well and turbo/turbos seem to be kicking in. No fault codes.
I went for a longer drive today and got the van warm. The van went into limp mode, down on power so seems like the turbos aren't working. There same fault code is 16408 Actuator module for turbocharger 1: Stuck P00AF_00 [100] Implausable signal
Im also getting the ABS,Tyre pressure not available and traction control light on until I've driven a little distance.

Can anyone please shed some light on this. Is it possible its just a sticky actuator or sensor? I can get the van up on the lift and have a look. Im pretty handy with the spanners and have a high spec Foxwell scanner/code reader. is it possible for a kind person to point me in the right direction please. Im not sure what is the best workshop manual to get my hands on either so a recommendation would be fab! I can't believe that after only 38k miles this van is giving me grief!!

Thanks in advance
Jay
 
So without any suggestions forthcoming so far I guess im on my own! I've downloaded the manual and will work through it and report back if it could possibly help others in the future.
 
Can your tool run engine's diagnostic tests?
There are quite a few which test various parts/functions of turbochargers.
 
Can your tool run engine's diagnostic tests?
There are quite a few which test various parts/functions of turbochargers.
I’m not 100% sure but maybe it’s time to go vcds. Not sure how to go about it. I’ll have to have a look as I’m sure it will pay for itself pretty quickly. Thanks for the reply.
 
Ok so some further developments. I replaced the battery with a like for like AGM type. I reset the codes and went for a drive. all was well and turbo/turbos seem to be kicking in. No fault codes.
I went for a longer drive today and got the van warm. The van went into limp mode, down on power so seems like the turbos aren't working. There same fault code is 16408 Actuator module for turbocharger 1: Stuck P00AF_00 [100] Implausable signal
Im also getting the ABS,Tyre pressure not available and traction control light on until I've driven a little distance.

Can anyone please shed some light on this. Is it possible its just a sticky actuator or sensor? I can get the van up on the lift and have a look. Im pretty handy with the spanners and have a high spec Foxwell scanner/code reader. is it possible for a kind person to point me in the right direction please. Im not sure what is the best workshop manual to get my hands on either so a recommendation would be fab! I can't believe that after only 38k miles this van is giving me grief!!

Thanks in advance
Jay
Did you ever get to the end of this?
 
Ok so now I’ve moved house I’ve had time to look at the van again
A friend who’s pretty good with diagnostics popped over and it seems the MAP sensor at the top of the engine was bad so that was replaced. This cured the turbocharger stuck fault code P00AF_00

Unfortunately there are now other faults!
Been working through them but stuck with one 27202 - P0641 sensor ref voltage A circuit open.

Been reading that the T6 wiring can be a bit fragile or maybe even a bit tasty to rodents. I’ve had a poke around to see any obvious damage but nothing really jumping out at me so planning on getting it on the ramp and maybe taking the battery out and the bumper off to have a better look.
Any ideas please
 
So without any suggestions forthcoming so far I guess im on my own! I've downloaded the manual and will work through it and report back if it could possibly help others in the future.
It happened to me mate. I replaced high pressure sensor (Brown), reseted but Glow plug light came back again. How did you end up? Thanks

IMG_1138.png
 
Got mine sorted.
After I spent and wasted over €1,500 on removing the turbos and getting them rebuilt (at the advice of a "Diagnostic Expert") it ended up being the actuator.
Replaced it with a new genuine part and haven't looked back.
 
Im half way through I hope. So I started from oil pressure valve (£32.00) It didn’t solved problem but new part at least. Watched YouTube where guy advised to check Solenoids ( I got 3 of them) and here we go. One of them was faulty. VW dealer shop asked £276 so went on google. Part shop in Holland sells it for £43. Just because I removed all three ( as per youtubes advise) I was 100% sure which solenoid is faulty and could see part number. So its Pierburg brand with identical part number only £43! Fingers crossed it helps.
My advise from what I already learned is, always start from simle and cheapest parts!
 
If it helps others, i started a new thread and resolved the problem with help from other members.

It turned out to be the actuator on the upper turbo that had gone bad causing the 5v reference sensor circuit to go to ground. This threw up loads of false codes. Replacement actuator from VW was £280

 
Got mine sorted.
After I spent and wasted over €1,500 on removing the turbos and getting them rebuilt (at the advice of a "Diagnostic Expert") it ended up being the actuator.
Replaced it with a new genuine part and haven't looked back.
Nearly went that way too! I started another thread on how I fixed it with help from other members on here. Glad to hear you got it sorted tho.
 
Back
Top