Engine light & EPC light. Fault code: P00AF

[AlexT99]

Fitted new battery and have had EPC and engine light lit since new one has been in. Have noticed a loss in power/reduction in rev limiter. E.g. will max out at just under 5k RPM. Or foot will be flat to the floor in 5th gear going 76MPH. Car wont accelerate and will suggest shifting to 4th.

Garage that done the MOT said it's throwing up error P00AF.

Anyone know if this is because I need the battery coding done? Or if I have somehow f****d the turbo by driving it with low engine coolant and/or a new battery. I haven't had any engine coolant errors or overheating issues.

Car failed MOT on the engine light but then passed after they cleared it

[Bepis]

P00AF comes back as a stuck turbo actuator:
http://wiki.ross-tech.com/wiki/index.php/P00AF/000175

However, could be related to the new battery and being sat dead for a while.
https://www.briskoda.net/forums/topic/4 ... for-a-bit/

You won't have damaged the turbo by running slightly low coolant or by fitting a new battery. But do get the new battery coded.

The lack of acceleration is likely down to the code being stored and the car going into limp mode, hence the EPC light. A stuck closed turbo actuator would mean over boosting and stuck open would mean no boost. If you don't have an over-boost or under boost code accompanying P00AF I think it's just an electrical gremlin that needs some driving to sort.

I'd clear the fault, get the new battery coded in and see if it returns after some driving then go from there.

Here's a video of an actuator fault on a 1.2TSi. It tends to be the pivot that seizes as shown in the video:
https://youtu.be/KzeBSEvu-i4?t=381

[Le_Combattant]

Get a good battery with the right code

After, erase all the codes and run turbo actuator calibration and after that, perform a road test.

[AlexT99]

Get a good battery with the right code

After, erase all the codes and run turbo actuator calibration and after that, perform a road test.

I've got a decent battery. Same brand and spec as original battery except previous was 59ah and new is 60ah.
Just came with no codes as it's an aftermarket battery.

Might take it to the VW stealership so they can code the new battery, do a throttle body adaptation and turbo actuator calibration.
As well as clearing the codes. Might cost a lot considering but at least they'll have the knowledge and the kit.

Taking it to any old garage is like I'm talking a different language when I bring up these things
How much do you think they'll charge me for coding a battery, doing a throttle body adaptation and doing a turbo actuator calibration?
I also need a full service as well as my brakes checked so was going to ask them to do the whole lot

[Le_Combattant]

Get a good battery with the right code

After, erase all the codes and run turbo actuator calibration and after that, perform a road test.

I've got a decent battery. Same brand and spec as original battery except previous was 59ah and new is 60ah.
Just came with no codes as it's an aftermarket battery.

Might take it to the VW stealership so they can code the new battery, do a throttle body adaptation and turbo actuator calibration.
As well as clearing the codes. Might cost a lot considering but at least they'll have the knowledge and the kit.

Taking it to any old garage is like I'm talking a different language when I bring up these things
How much do you think they'll charge me for coding a battery, doing a throttle body adaptation and doing a turbo actuator calibration?
I also need a full service as well as my brakes checked so was going to ask them to do the whole lot

To be honest, I don't know they will ask you for all of that. But you can be sure, it will be too much.

I have an OBDEleven that I can connect on my phone with Bluetooth. With this kind of device I can do 90% of my maintenance of my care, coding a new battery, throttle body and turbo actuator adaption.
So for me, it's free.

For exemple, on my last service (oil replacement, spark plug etc...+ battery they ask me....870 euros.

And you want to know the joke ? The chief mechanician gave me a call to ask me if I wanted to replaced all disc and pads (they were worn, I knew it).

I said "Why not, how much it will cost"

"You are lucky, it's only 900 euros"

Man, 900 euros for 4 f*****g brakes discs and 8 brakes pads.

I bought part on internet (the brand is ATE) and for 220 euros I had everything.

In conclusion, do the maximum you can. You will save a lot, a lot of money.

[Bepis]

Dealer will be the most expensive route, I'd try and find a reputable independent or specialist in your area.

If you wish to make the investment in your own diagnostics VCDS and OBDEleven are probably the best options for VAG. VCDS you'll need a laptop, OBDEleven you just need a mobile app.
VCDS 3 VIN £225:
https://www.gendan.co.uk/product_VCV23.html
OBDEleven VAG-Only Pro pack £86:
https://obdeleven.com/products/pro-pack ... Volkswagen

I've only ever used VCDS and it's always been able to do what I need. I prefer using a laptop than a phone purely for the screen size and being able to quickly flick between a web browser and Excel. I think in your situation OBDEleven is probably the best option but I can't comment on using it as I never have.

[AlexT99]

P00AF comes back as a stuck turbo actuator:
http://wiki.ross-tech.com/wiki/index.php/P00AF/000175

However, could be related to the new battery and being sat dead for a while.
https://www.briskoda.net/forums/topic/4 ... for-a-bit/

You won't have damaged the turbo by running slightly low coolant or by fitting a new battery. But do get the new battery coded.

The lack of acceleration is likely down to the code being stored and the car going into limp mode, hence the EPC light. A stuck closed turbo actuator would mean over boosting and stuck open would mean no boost. If you don't have an over-boost or under boost code accompanying P00AF I think it's just an electrical gremlin that needs some driving to sort.

I'd clear the fault, get the new battery coded in and see if it returns after some driving then go from there.

Here's a video of an actuator fault on a 1.2TSi. It tends to be the pivot that seizes as shown in the video:
https://youtu.be/KzeBSEvu-i4?t=381

Well. You deserve a round of applause. After reading somewhere that you should be able to reach behind the engine and pull the actuator pin back and forth, I thought I'd give it a try. Man that thing gets hot and is really hard to grip as it's in a tight spot. But I had success while pulling the piston towards the passenger side whilst simultaneously hand twisting the pivot end. It moved and seemed to get stuck. I sprayed a bunch of WD-40 on the pin and on the pivot and repeated the procedure a few times. It still felt stuck so I didn't have high hopes. Although it is stiff as it's geared apparently.
Started her up and voilà, we have BOOST.
Turbo kicking in fine.
EPC light gone off.
Engine light gone off.
Start-stop working.

Seems like the car just thinks it's using the old battery. Stop-start is not supposed to work until the new battery is coded. But they're the same spec. Except new is 60Ah instead of 59Ah
I'm not sure if this is a good thing as the old battery was dead so the alternator might not be charging it properly or might even be overcharging it.

Thanks though. The fun of driving it is back

[Bepis]

Good stuff

Once you've got the brake situation sorted "exercise" the actuator with a decent amount of hard acceleration pulls.

Odd that there wasn't an accompanying low boost or over-boost code maybe being electric it has a self-test at some point.

Also do still get the new battery coded, if you don't have a BEM code on the new battery then just have the last digit of the serial number changed, then the capacity and battery type can just be updated as per what you have fitted.

[AlexT99]

Good stuff

Once you've got the brake situation sorted "exercise" the actuator with a decent amount of hard acceleration pulls.

Odd that there wasn't an accompanying low boost or over-boost code maybe being electric it has a self-test at some point.

Also do still get the new battery coded, if you don't have a BEM code on the new battery then just have the last digit of the serial number changed, then the capacity and battery type can just be updated as per what you have fitted.

I have filled her up 3/4 with E5 and give it a good spin. Even though the brakes may be sketchy, they are still doing their job, just may fail to provide enough friction if an emergency stop was needed.

Is battery coding really necessary now though? The car is happy as far as I can tell. No errors, start-stop working.
The OEM battery was an 59Ah Exide EFB 640A EN/CCA which I replaced with a 60Ah Exide EFB 640 EN/CCA.
So almost identical specs apart from 1Ah. As everything is functioning fine now, what could happen if I don't get the serial no. changed and rating changed from 59Ah to 60Ah ?

I just know that the dealership that I plan on taking the car to for a service will charge wayyy too much, or may even refuse to do it saying if there's no BEM code that they can't etc.

Won't the BMS/ECU "learn" how the battery that is installed is functioning? I.e. if it got used to a poorly performing battery(the old one) it would pump loads of charge into it from the alternator, but once it learns that it's now holding 12v, it will adapt to suit?
Yes I am just trying to get out of coding it. But only because there doesn't seem to be any competent garages nearby that aren't the dealership