1.8T AEB Random Stalling, Hunting Idle, No Check Engine Lights (CELs)

[cheap_b5_a4]

Buy a throttlebody gasket for $2 and pull the throttlebody off of the car and proceed to spend the next hour cleaning it. I mean, clean it good so it looks nice and shiny on the inside. I used gasoline (if it is good enough to clean out an intercooler, I figured it'd do great on a throttlebody which it did) and paper towels.

The 105k mile A4 we have developed a random intermittent stalling issue when slowing down/turning. The other symptom included hunting idle/rougher idle than what I thought it should be (but, hey an i4 is never as smooth as a BMW i6). After replacing MAF, o2 sensors, cam position sensor, battery, and completing TBA, it turns out it was a dirty throttlebody. The idle has never been so idle good on the car. Likewise, I could introduce hunting/bad idle by holding the brake, this car is Tiptronic Quattro, and revving the engine up and then letting off of the gas. Post-cleaning, idle immediately finds its spot and it is very stable even while running AC and headlights.

And, I reiterate, no CELs from this event. The car would just stall. It bothered my wife so bad, we bought another car due to this issue.

[B5Riches]

Ok whenever u mess with TB on aeb u need to recalibrate the tb adaptions u can do this manually by pressing down gas pedal first then turn key to on for 20 sec n let go of pedal then turn key of. Repeat it until it works but double check the process or vag com


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[xdewaynex]

AEB will need a throttle calibration with VCDS, its the only way Ive been able to get it work.

[Radskull1]

AEB will need a throttle calibration with VCDS, its the only way Ive been able to get it work.

Do this, the chicken dance never works. If ur car is pre 2000 check the little icm on the airbox, mine went bad car felt like it wwas running 3 cylinders missing every other stalling ect, a throttle body alignment in vcds is very useful too

[Wrath And Tears]

He did that, the issue was he adapted a dirty (really dirty) throttle body. VAG tells us this is a big no no and to always clean out the throttle body before adapting it.

[cheap_b5_a4]

I did not run adaptation after removing the TB and had no issues. Also, when you clean it DO NOT immerse the throttlebody; wipe it out.

Again, this overall design by VAG is pretty weak. I still prefer having a seperate idle control valve (and non-VAG cars in general).

[mario90]

I'm experiencing somehow this problem. The car doesn't get any CEL, but when I press the throttle, the car doesn't Rev up. Did you have the exact same symptoms? I have already changed the fuel pump (I think this was not necessary, but my mechanic told me that the pump was bad), and the ice module....

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[Rodgman15]

I've completely immersed throttle bodies in e98, water, solvent, etc etc. Removed to paint, replace gaskets, clean etc etc. Switched throttle bodies for no reason whatsoever, and have never ever once done an adaptation. Put a different engine in with a completely different throttle body, I'm convinced tba is a joke. Maybe it'll help you, maybe I've been lucky, who knows.

[10kredline]

I'm getting this same issue also. Seems like these symptoms occur only in hot California weather. Is it necessary to replace the whole throttle body or cleaning is good enough? Also, I thought AEB don't need adaptation since it's drive-by-cable. I know drive-by-wire is required but not sure about AEB. I've never had to do an adaptation once EVER.