1.4 TDI 90bhp ATL engine intake manifold flap motor fix (?)


What state is your exhaust in? Excessive back pressure from an exhaust can trigger all sorts of issues with engine management.


Good shout its going up on ramps on Monday so I can add that to the list of to do. Deproman and I were looking at it indirectly a couple of weeks back and nothing obvious was seen however I do mean indirectly - the backbox was squeaking!


When you say iPod was not getting enough power this makes me thing that the battery or alternator may be bad. If there is a low voltage situation occurring the ecu will through all sorts of error codes. Theory only - the flap motor will draw a good few amps and the wiring is fairly long especially with battery being in back of car. Is it possible that voltage drop is occurring and the ecu is seeing this an intermittent connection ?
Suggest monitoring battery voltage with a multimeter when can is started and ticking over. Try to replicate the conditions as closely as possible to when the eml came on ie temp time of day amount of time car was started to when eml came on

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So battery is only a few months old and its a Varta 110 80A...decided to change when I was getting patchy starting during the winter months. Voltage usually fluctuates around the 12-12.2 range but if the car hasn't been started for a while it can go down to 11.5-6 range.

I've got a 12v socket / USB socket thing on the car with a button on it that reads out the current voltage so quite handy
Hi buddy.

That sounds low

If the battery is in good condition and fully charged you should be getting about 2.2v out of each cell so freshly charged should read about 13v dropping to 12.7 or 12.8 after a few hours and about 12.65 is a fully charged resting battery.

A battery sitting at 12.45 is only about 75% charged. 12.25 is 50% and 12v is 25%. Anything under 11.9 is dead.

This is for an unloaded battery of course and you can see these voltages and still have an exhausted battery (with no endurance) but yours is new!

I had an issue with my dash cam draining 5v and it was enough over a couple of days to kill my battery. Do you have anything drawing while it’s sitting?

Otherwise you maybe need to check your alternator is giving juice.

Can you maybe do a charge on the battery and see what happens?

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I'll check it tonight with a proper multimeter rather than a gadget attached to a 12v extension.

I do dread having to trace down something draining the battery!


ok so quick check with the USB thing I have......12.3v read when I went out after that car had been off around 3-4 hours.

When car is idling the car reads 13.8V / off it immediately went down to 12.8 and I can noticeable see it declining to 12.7 within a couple of secs.

Checked for drains and it looks like without any obvious stuff its around 0.3A draw - not huge I guess but no idea if that's considered "normal".

Is it worth getting hold of another alternator and replacing?


Right think draw is ok... measured again when i had more time and it's only around 0.03a. Going to try a be alternator belt first


I'm with Pinky your resting voltage seems too low, the A2 is prone to all sorts of fault codes if the voltage drops when cranking the engine
My own A2 in the winter months would one a fortnight pop up the ABS warning light on the dash, with a P code stating intermittent. I cleared the codes and all was well every time. The cranking was not spritely in the depths of last winter (My battery is 17 years old and never failed to start or even came close to not starting, but the lack of battery voltage caused fault codes to be issued)


Yup just ordered gates belt and tensioner set (k016pk995) and INA AlternatorOver Running Clutch Pulley 535001210- 80 quid! The alternator itself seems to be boosting when I turn on the engine so I'll park that and hopefully this will fix a number of issues as even with the new high power battery starting in winter wasn't always great!

I'll try to get mechanic I know to fit on Monday along with new brakes / pads and calipers. Ka-ching :(
Sorry bud.

Finding a voltage drain shouldn’t be too bad. You just do what you’ve already done and pull out fuses one at a time to see what happens.

I wonder if maybe it was a higher draw then Canbus shut something down? I think that happens. Did someone not post about a boot light that stayed on - or maybe a glove box light - and that was enough to nibble the battery down to dead.

My own dash cam is hardly power intensive but three days without driving and the battery was unrecoverable. Wouldn’t even turn over the engine. Had to replace it as it had gone so low it couldn’t be recharged. I think 6v was reading on the charger - it was convinced it was a motorcycle battery and I had to force it onto 12v mode.

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A2OC Donor
Changed V157 on my ATL today due to fault code P3103 / 19559
Used an aftermarket, was quick available and nicely priced:

Fault code removed and did not return.
Old valve was sticky and got stuck halfway now and then when cycled with hand.

Edit 3-4-2019:

Do not buy above aftermarket valve: check engine light emitted again, same fault code P3103.
Cleaned old valve (original VDO), found gears worn, but managed to rotate gear so they engaged again and faultcode dissapeared and all is fine now for a couple of days again.

Opened up new valve, circuit board is not protected against oil or moisture, pictures: https://www.audi-a2.nl/viewtopic.php?f=11&t=8008&start=50
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My EML and shudder came back a few weeks ago and I have just stripped it , cleaned the ASV motor and reassembled it for a 3rd time now at 118,029 miles. The last time was more than 18 months ago. Quite oily but only about a teaspoonful inside the body. The gears are still fine. Again I dunked it in and out of paraffin for a few minutes, gave the motor a good shake and screwed it all back together. It took about 45 minutes in all, including getting the laptop and VCDS hooked up, clearing the fault code and a few on-off tests to confirm it is fixed again.:cool:
Now all I have to do is fit the spare cat and oil filler / dipstick pipes on Project FSI, as supplied by @A2Steve, clear its fault code and I'll hopefully have 2 EML-free A2s again for a while.
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Hi guys, undertook this rebuild using this thread as a guide on jules today and thought I would add a bit to it in order to improve it and help future users.
Before you remove the motor and large white cog put two marks with a pencil one on the white cog and one on the shaft housing fin side (see pic) to indicate exact alignment prior to removing the two small torqs as the big white cog has a small section which is slightly different on the small fins that connect directly with the shaft fins, also recommended is a small amount of silicone grease on shaft fins, I found that it made the operation quite a bit smoother after I had re-inserted the motor( you don’t need much just a little).
Hope this is of some help to anyone undertaking this job. It’s a fairly easy job I found 😀


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Hello all. I also have the V157 flap motor fault on my 04 Tdi90 / ATL. I did have a bit of luck clearing the code for the EML to extinguish, but no longer could the fault be cleared, so I removed the flap motor on Sunday for a clean. It was pretty oily in there, but appeared to clean out OK, and all gear teeth were fine. Both before and after the clean 6v across the motor with the electronics removed actuated the flap smoothy. Once back in the car I was able to clear the code, but alas for only one journey before the light came back on, and again can't be extinguished.
So, I had another removal and clean (not much oil had reappeared). Motor still smooth when tested. But still no reset of the EML light possible. And viewing the flap exposed with a quick run of the engine to turn off again showed no attempt by the valve to move.
So, I guess it's replacement time, but just before I do, I wouldn't be missing a fuse or something silly would I? I'll have a look along the wiring run too - is it obvious which route the wires follow?