Only when cold & after a couple of mins driving - no throttle response after coming to a stop/slowing to a stop. Leaves me stranded at junctions!
Shut engine off - restart - won't rev, even in neutral. Sits on 1k revs.
Place in neutral and it won’t rev whatsoever, place in Drive or Reverse and put foot down, after several attempts it’ll kick in, and then drive as normal for the rest of the day! - Always OK when warm.

Indications
None! No transmission flashing lights, no CEL or DTC's, nowt in memory when scanned with VCDS

Tried
Throttle Body & Butterfly plate removed & cleared of gunk then re-aligned adaptation via VCDS
Garage checked for vacuum, lean codes and emissions ok
MAF & Air Filter replaced
Brake Pedal sensor replaced – it cut’s out throttle and is “known fault”
10 tanks of Premium fuel used, and countless injector cleaners/additives over past months.

This has been occurring for about once a week for 6 months now.
Any advise gratefully received!!
A4 cab 3.0 V6 Auto - ASN 8H7 2003
Edit/Delete Message

 

Could it possible that the 'fly by wire' accelerator pedal be causing your problem?

They are just a variable resistor connected to a pedal really. I had one Audi A2 customer who had similar issues and when measuring it generally it would be ok but occasionally after several measurements it would have a big dead spot.

Changing it has resolved his issue....so far (6 months), 'may be' same for you?!


Cheers
Sarge

 

When replacing the throttle body (the piece of the air intake system that controls the amount of air flowing into the engine

 

.....missing a bit?

Anyone have the part no. for the Throttle Pedal Sensor? Worth a try.

Will also hassle Audi to flash the gearbox ECU.

 

Hi Paz,

Have you managed to find the solution to your problem? I am also having the exact same problem your are describing, word for word. However it was minor in warmer weather and significantly worse in colder weather now. I am desperate for help, I also have been recommended to replace the parts you have suggested you have already replaced. The only problem is no one is guaranteeing a fix from it so I would like to know what you have done to fix this problem.

I appreciate you taking the time to write a response.

 

Hi aastan11,
In short, no; I've learned to live with it, commuting 1400 miles a month.
The summer months are fine and it only becomes a problem when the seasonal temp drops to 10°c or less.

The problem is during the "warming up" phase, and I know when to anticipate it. When it does stop responding at the lights or junction, leave it in D, keep a foot on the brake and then depress the accelerator - the revs kick back in within a second or so, and it's fine after that.
Not an ideal resolution, but then neither is a replacement gearbox at £4K+

All indications are that the problem lies within the CVT gearbox linked with the ATF(Auto Trans Fluid/oil) temperature: CVT Audi Multitronic Transmission Hints
I had intentions of doing the "Block 65 test" but as yet haven't.
1yr ago I did have a full gearbox oil change for £250 by Mega Flush Gloucester, Bristol, Swindon & Bath, UK - Gloucester Road Gearboxes and this did seem to make it better for a while. It also reassured me that there were no metal particles or filings within the old oil.
Think I'll do a test to see if the problem occurs when the ATF always hits a certain temp, as I'm positive it is. (VAGCOM, select Auto Trans 03, Measuring Blocks 08, Display group 10, ATF temp is shown in Zone 3)

Good luck & keep me posted!

 

I'd say this is our problem:
Audi A4 Automatic Transmission Problems

 

Hi Paz
My wife has a 2003 A4 1.8T with CVT. she has had the exact same problem being stranded at junctions; throttle completely unresponsive for maybe 1-2 minutes. On slowing down for the intersection just before it happens, there is usually a tell-tale momentary 'hesitation' in the engine note, accompanied by the car briefly trying to surge forward. A no stage has a fault code logged ever been logged in the computer. Over five years it has probably occurred at least 12 times. The biggest problem is that the fault is intermittent and infrequent

We had a trusted mechanic look at it. He said the throttle was not registering on the VAG as it should, but NB this was when the car was behaving normally, so unsure of significance. . Mechanic contacted Audi Australia who pretty much denied knowledge of it.

We tried the following fixes: Check all wiring and plugs, swapped the throttle sensor (pedal unit inside cabin), With the unit from my A4 V6, which uses the same electromehanical transducer. No change. Next- Removed, checked, replaced engine air mass sensor, O2 sensor, temp, timing and fuel sensors. The mechanic drive the car for one month on test, and got the fault to happen once - at the entrance to his workshop! After the fault self-cleared, leaving no trace in the fault log, he was still none the wiser. We replaced the engine management computer (AUD $3K).

One thing that has helped was switching the A/C off, by keeping it in Econ mode as much as possible. There have been a couple of engine hesitation episodes slowing down to intersections in the last year, but no episodes of being stranded with an unresponsive throttle.

I am wondering if it is an engine management software routine problem, triggered by certain combinations of temp / revs / load. I understand it is possible to tailor the delay in RPM reduction as the engine returns from ~1500 rpm to idle, in the last stages of slowing to a stop, and possibly increasing this could offer a solution.

My wife will definitely try the fix of partial accelerator while pressing the foot brake next time. I am very glad to have seen this in the blog. I suggest try leaving the a/c in Econ mode as much as possible (improves gas mileage too ).

Cheers

Derek

 

I did ponder on whether to have the idle tampered with, but didn't know how it would affect the holding/creep (or whatever it's called) at junctions.

I can only add that I seldom use the A\C, what with the British climate being what it is; should the sun rarely come out, I drop the roof.
Then look a dick when stranded at the lights.

 

Paz, have you changed your pedal position sensor?

Also, there should be a set screw for a positive stop of the throttle plate. If it is out of adjustment the throttle plate will basically jam itself shut (wedging itself against the throttle body walls)

Your throttle body servo might also need replaced (but I'd save that for last)