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00575 AFN fault code

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mike1978 View Drop Down
Yardie
Yardie


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Post Options Post Options   Thanks (0) Thanks(0)   Quote mike1978 Quote  Post ReplyReply Direct Link To This Post Topic: 00575 AFN fault code
    Posted: 15 Feb 15 at 11:43
Hi, driving the van today and got a sudden loss of power, then it seemed to recover.

I checked fault codes and got a 00575 which looks like intake manifold pressure. I had a quick look but all hoses look ok - is there anything else I can easily check or common causes did the code?

Cheers, mike
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1989 T3 Bluestar AFN TDi Flipped Gearbox
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mike1978 View Drop Down
Yardie
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mike1978 Quote  Post ReplyReply Direct Link To This Post Posted: 15 Feb 15 at 12:53
Just carried on driving and instead if 15-16psi I'm only getting max 3psi according to my ultra guage - so defo have a prob!

Going to jack the van up and take a proper look .
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mike1978 View Drop Down
Yardie
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mike1978 Quote  Post ReplyReply Direct Link To This Post Posted: 15 Feb 15 at 14:31
Just did a boost test and it looks like I have no leaks - managed to test up to 15psi, then it slowly dropped as expected to 0.

Guess I have some other prob. It's strange - I hear the turbo spooling up when I'm driving, but no performance. my ultra guage gives max 3psi.

Is there any way to test the n 75 valve? Or turbo? I can move the actuator arm on the turbo and it springs back. I doubt it would be clogged up but you never know. It was cleaned up 5k miles ago and the van gets a good 60 mile run every day.

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Vanorak
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Post Options Post Options   Thanks (0) Thanks(0)   Quote light Quote  Post ReplyReply Direct Link To This Post Posted: 15 Feb 15 at 18:19
Could be the map sensor broke or the pipe insisde the ecu feeding the sensor ,if broken there will be no extra fuel added to maintain/build boost 
 
 

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mike1978 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mike1978 Quote  Post ReplyReply Direct Link To This Post Posted: 15 Feb 15 at 18:47
Thanks - yes, i thought it could be the map sensor possibly. I think i`ll change the pipe going to the ecu from the intake pipe as i`ve heard of them getting a bit blocked.

I had the ecu apart a few months ago when it was remapped and the pipe going to the map sensor looked good externally, but i may also change that too and give it all a squirt with some electrical cleaner.

I think its difficult to get hold of the MAP sensors which go inside the ECU - i`ve read i can convert it to use the later MAP sensor, but a bit of soldering to the ECU is required.

Its funny how this problem has suddenly just appeared when everything was working fine.

I cleared the code and went out for a test drive. Boost stays arouns 2psi  when it would be 6-7 cruising and its really flat. When you put your foot down, there is a massive turbo lag and then the turbo kicks in and boost will very slowly increase to about 11-12psi (if i`m lucky).

I`ll have a look at changing the pipes tomorrow night as they`re fairly easy to do and won`t cost anything.

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randolph57 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote randolph57 Quote  Post ReplyReply Direct Link To This Post Posted: 15 Feb 15 at 20:19
Mike
i think you are looking definately in the right area for the underboost you are experiencing-I would check the correct operation of the actuator with a mity vac or similar. A defective actuator can or vacuum hose from N75 to it would make the Turbo very 'laggy' and unresponsive.
The operation of the N75 and the tubo operating rod can be checked by a test in vagcom if you have it  but if you are using the jx exhaust manifold with adaptor plates and engine at 50 degrees my money would be on the pipe to the actuator can being holed where it tucks up near the block as its close to various 'hot' items.

Good luck

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mike1978 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mike1978 Quote  Post ReplyReply Direct Link To This Post Posted: 15 Feb 15 at 20:36
Thanks - yes i am using the JX manifold and adaptor plates. The vac pipe is very close to various hot items and i`'ve already had it melt once! Its out of the way now and would`ve shown up in the pressure test, so hopefully thats all ok.

I only have VCDS lite so not sure the n75 test is in my version, but i may look for it.

If replacing the MAP sensor feed pipe and cleaning it tomorrow doesn`t have any affect, i`ll look into getting hold of a mityvac thing to test the actuator - (it`ll come in handy for brake bleeding anyway!)

I think i`ll also replace the other vac pipes while i`m there as i have some new silicone piping i`ve been meaning to fit to replace the braided pipe fitted.
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mike1978 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mike1978 Quote  Post ReplyReply Direct Link To This Post Posted: 16 Feb 15 at 20:41
Well, i removed the ECU tonight and had a look. the pipe to the MAP sensor was ok, but i renewed it anyway.

There did appear to be black oil inside the MAP sensor and pipe which i blew out with electrical cleaner and then some compressed air - went all over the circuit board which i then had to clean up aswell!

The MAP sensor has such a tiny nozzle, i don`t know if i got it all out, but its got to help even if its not the problem!

I also renewed the vac tube from the turbo to the ecu - that is not easy to get that vac pipe back on the turbo can!

Was a bit worried about the van starting again after messing with the ecu, but it did  - thank feck for that!

If this doesn`t solve the prob, i guess i`ll prob look at cleaning/renewing the MAF, swapping in another N75, then looking at the turbo.


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mike1978 View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mike1978 Quote  Post ReplyReply Direct Link To This Post Posted: 17 Feb 15 at 19:19
Before i took it out, i thought i`d have a quick look at the MAF sensor too and give it a clean aswell.

Through the gauze, i could see that it was pretty covered in black oily stuff - not good! Typically, this MAF was designed so you can`t access the element bit to clean! One new MAF later and went for a test drive.

Straight away, i could tell, the boost was picking up and once on the open road, much better Smile

I`d say its driving better than before (touch wood!) - the boost picks up much quicker with less lag and flat out, the boost is topping out at 17psi instead of 15psi before.

Will see how it drives over the next few days. I have a theory of how the sensors got gunked up - my gearbox breather was routing to the air intake and because i didn`t route it quite right, it was dripping gearbox oil and vapour into the air intake covering that area in oil. I`ve since got the routing right so it doens`t leak and i`ve also moved it to the opposite side of the van. I reckon this wasn`t helping!


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VW Nerd View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote VW Nerd Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 15 at 20:30
Only just seen your post mike. The slow up take in boost is likely to have been the pipe from N75 and the actuator can on the turbo. When they become perished, air leaks in through the cracks and the turbo is unable to give full boost.
It is fair to say that the ecu mounted MAP sensors do give out with age, but its usually best to check the vacuum pipes before the MAP as these suffer the most from where and tear.

Glad to hear that you are up and running again.

Tim.

Developing parts for the VW T3 TDI market Inc flipped audi gearbox install parts.

Tim Shettle
www.ultimate-engineering.co.uk
Bristol

Tel/txt 07810 320 464

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mike1978 View Drop Down
Yardie
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Post Options Post Options   Thanks (0) Thanks(0)   Quote mike1978 Quote  Post ReplyReply Direct Link To This Post Posted: 18 Feb 15 at 20:45
Yes - the MAP sensors in the ECU are pretty hard to get new so my best bet is to clean the current one out. There are couple of articles (i managed to get a PDF) showing how to retro wire in the MAP sensor from a later AFN which is located in the intake pipe as part of the temp sensor. 

Obviously that means tinkering and bit of soldering on the ECU board which i`d rather avoid if possible!

Anyway,  i`ll see how it goes over the next few days of driving Smile
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