Help Needed

[florinnd]

Hello.I have joined the forum after reading all that I could read about a problem that I have.My Audi A4 1.9 tdi from 2005 , few months ago on rainy weather showed me the brake light erorr then esp and glowing plug.Engine stuck at 1200 rpm on M2 motorway.Got home with only 40 mph...removed the negative connector to the battery ..adter an hour when reconnected...everything went back to normal.Few days ago..same storry..also in a morning..same problem.Got back home..read everything I have found...cleaned the MAF and MAP ( with no change) .. untill I have found a thread that somehow because of a faulty ECU cover box , water enters into the lower part of it shortcircuiting some vonnections.Also the floor in the drivers part was wet.I have dried the floor oppened the ecu plastic box ( i have seen that it is cracked on one side) cleaned everything waited to get dry , mounted all back and the only thing that got fixed from this was the brake sensor which stopped appearing.The engine starts smoothly...idles ok but when I press the accelerator immediatly I see ESP light and Glow plug light and the engine goes from mormal idle to 1200 rpm and that's it.I have ordered a cable to read the codes but I am out of Ideas.Any help and suggestions are more than welcomed.Thank you very much.This firum is very helpfull I have learned so much from it in the last few days.
And something else.How cqn I reset tge ECU untill my OBD device arives? Unplugging the negative of the battery, waiting 20 30 min , replugging , turning the ignition to 1 waiting another 5 minutes , starting the engine , waiting another 5 minutes , then restarting doesn,t help.The only thing that redets..is the clock.
Thank you for your time and do please excuse my english.

[Crasher]

Without fault code information you are stuck.

[florinnd]

Tuesday I will have it.Thank you.

[florinnd]

So it arrived earlier...i have printscreens for everything i could find.I am not in the field so I jope you could light me up.
Thank you again.Florin

[florinnd]

And the Fault code was P2102.
Thanks.

[pauldazzle]

IIRC.
P2102 is a throttle flap fault. There are some relays under the ECU box, one of which is related to the throttle, & I think there's a fuse too. If water has got in there that could well be the source of your problem. If not it's probably the Throttle body motor at fault.

Crasher will no doubt be able to clarify.

[florinnd]

Thank you very much.

[Crasher]

P2102 Throttle Actuator Control (TAC) Motor - Circuit Low

I am assuming you have a BKE (you haven't told us) as these have a manifold flap unit which is what the code could be pointing to but I think your generic code reader is misinterpreting the code stored, a proper VAG specific read would probably give a different result that would make more sense.

The unit this code is suggesting is called a V157 and these are on the inlet manifold before the EGR valve. All three of these parts can become absolutely blocked solid with carbon and often we end up fitting a new flap, EGR valve and soaking the inlet manifold over night in a strong alkaline to eat through the crud AFTER we have scraped most of it away.

Typical 8 valve model V157 flap

http://i222.photobucket.com/albums/dd20/Crasher1964/V157carbonbuild_zpsb81da1c6.jpg (http://s222.photobucket.com/user/Crasher1964/media/V157carbonbuild_zpsb81da1c6.jpg.html)

Blocked inlet manifold after EGR valve

http://i222.photobucket.com/albums/dd20/Crasher1964/Blockedinletmanifold_zpsce855545.jpg (http://s222.photobucket.com/user/Crasher1964/media/Blockedinletmanifold_zpsce855545.jpg.html)

Typical blocked electrically operated EGR valve

http://i222.photobucket.com/albums/dd20/Crasher1964/EGRcarbonbuilup_zps5a6896bd.jpg (http://s222.photobucket.com/user/Crasher1964/media/EGRcarbonbuilup_zps5a6896bd.jpg.html)

Fully rebuilt unit from a T5 which is pretty much the same

http://i222.photobucket.com/albums/dd20/Crasher1964/Rebuiltinletmanifold_zps9d04cb4e.jpg (http://s222.photobucket.com/user/Crasher1964/media/Rebuiltinletmanifold_zps9d04cb4e.jpg.html)