Desiderata

My '98 A8 transmission seems determined to shift crazily when driven easy between 1400 and 1800 RPM (feels almost like an engine surge as it slips in and out or a torque converter lock up going in and out) Dealer thinks it might be engine management not the trans since it's fine under stressed driving. Anybody been thru this one before.

skiwi

has the dealer pulled any codes?

Desiderata

He says it is not showing any; but for some reason seems to be focused on wires and plugs

quarterdeck

My '97 wants to downshift while decelerating (coasting) from 75+mph to 70, and an additional time at higher speeds. It's really a bump and release and does not shift downwards. One audi dealer said they could not replicate the problem while test driving (although it happens every time at those speeds), and the other dealer determined it to be a faulty ECU. I ordered the ECU used because I did not want to spend over $2,000 on a five year old 90K mile car (at the time) that ran fine otherwise. Anyway, the parts place sent a trans. control unit by mistake. I returned it and over a year later have not replaced the ECU. I'd be interested in knowing what you find out.

Excellr-A8

My transmission has been doing this for over eight months. I have changed the fluid twice and it doesn't help this problem. It acts just like an engine surge but I am sure it isn't since that much of a surge would be very noticeable if the transmission were in lock up mode.

About two years ago I started to have the thumping problem on deceleration when on the highway. That was diagnosed as a torque converter going bad. I believe this latest symptom that you have described is just the next step in this process. The torque converter going bad but if there is sufficient load then there is enough fluid pressure to hold the torque converter in lock up.

I have found that if you put in one gear lower it will fix the slipping/surging problem. I use the Tip mode a lot more since it is easier to downshift when this happens. You will want to have your transmission recoded according to AudiPages.com if you are using the Tip mode very much at all. I think that eventually this will become a more serious problem but I have been able to live with it until it gets worse.

Jeff B

SawyerA8

My car has been doing this for over 6 months. I have changed the fluid. I drive a mountain pass almost everyday, so I get the hunting symptom everyday on the exact same part of the pass. One day I drove like a grandma and noticed it didn't happen. I started out drivng like a grandma from my house. I'm wondering if this is an ECU programming issue. Maybe it just doesn't know which gear to be in so it acts funny. If you can find out the problem or at least narrow it down even more - you will be a hero on this board.

Take care,

Noel Sawyer

AudiNutA8A6

both cars never through any codes, it seems to be an ecm issue hunting for the right gear at certain rpms (1500-2000 A8)(1800-2000 A6).

ryoung

I wonder if defeating this feature with VAG-COM would lock the tranny ECU in a mode that's less susceptable to this problem.

Personally, I never liked the adaptive shift program anyway; since it assumes I rarely change my driving style, it often guesses wrong.

SawyerA8

Re: Anybody have a VAG to test this out?

skiwi

reset dsp before you set out next time