tried searching, found nothing matching this problem i'm having. car is a 96 a4 that was probably built 95 as it is pre-obd2. having intermitent trans falure. also my speedo stopped working. the trans problem is "on" one day "off the next. one day it just stopped working after coming out of a store could not reverse to get it out of the parking spot! had it towed and it sat for a few months before i could pay attention to it. put a new bat. in it and started it up. put it in gear and found it drove perfectly fine! no sloppy or harsh shifting, no vibration ect. drove it for a day and the next day it will only engage first and reverse this time. the indicator lights on the dash are all lit up. think i have a 2 part problem. found the wires going to the speed sensor had been frayed. respiced and now have a speedo. thought that would fix the trans too but no luck. seems pretty fair to say that it's not a transmission failure but a computer or electrical problem. it's like a light switch. either off or on. when on, the car drives like new. did some reasearch and found there are only two basic input functions from the trans to t he ecu- speed sensor and range selector. my question(s) are - this car being pre-obd, does it have a seperate tcm or are the trans functions controlled by the ecu? if i were to replace either, would they need to be reprogramed by the dealer? also- anyone know the range of value's on the speed sensor and range? like to test the sensors themselves. thought fixing the speed sensor wires would solve my problem but it didn't (gave me back a speedo tho ) car belongs to a friend of mine. as for me, i'm a previous gm/cyrysler tech. have good knowlage but my first crack at audi. she brought it to a trans shop at first . any guess what they said? you need a new trans and quoted her $1500 for a "used" trans installed. i've built/ rebuilt auto trannies before. there is no way the trans is faulty. they performed NO diagnostic what so ever. when asked they said they needed to pull it to check it out. .....lol. no pressure checks, no scan codes . one more question if it's not too much in one post= how to jump the pre-obd test port to get codes? thanks VERY much...

 

When was the last time you flushed the tran? Could be some air in the system, could be a blockage. Either way a flush and filter change should clear it. Btw. you'll need mineral oil based tranny fluid.

 

your car is OBD2, the connector is next to ashtray in the rear of the center console. my A4 was built 95 too and is still considered 96 (i actually have one of the few audis without sunroofs which is sad because its a standard feature) your right it sounds like your TCU is out, not sure on older audis (only owned manual audis) but im sure its located in the passenger side footwell. first though run the diagnostics. ive noticed if you own and audi and plan to do your own work get a cheap obd2 reader off ebay so you can read and clear codes, most should read engine, tranny, abs ad srs computers. once you have the codes it should be easier to diagnose the problem. but since you said all the gear are lit up, it usally means the TCU is out.

 

the plug is located by the ash tray. it's on older style plug, not obd 2 (96 post) style. SAudi, agreed it's probably the tcu but can't really rule out the range sw.
forrest, probably wouldn't hurt to do a trans flush but the opperation of the trans when driven yesterday was flawless. if the trans fluid was the culprit it wouldn't shift right no matter what, hance my belief it's a trans control problem . the book i have is pretty much useless. does discribe the trans range sw. but not in the trans part of the book. only in ecu inputs. thanks for the input.