Hello everyone. I am new to this forum, but not to Audis...I had two when I was in HS.

I just bought a 98.5 A4 1.8T w/auto transmission and tiptronic. Here is the problem I was having - The car would not go into reverse, all the gears highlighted so you couldnt tell which one you were in, car seemed to be in limp home mode. I researched the forum first - and found out it was probably the neutral(multifunction) switch. I first started by trying to clean the connection but it looked pretty clean and it did not help. I figured the switch was shot so I went on eBay and found one fairly cheap(its even OEM) for 100 bucks. I emailed the seller because the part numbers did not seem to match and they assured me that this would work on mine. I just finished installing the new switch with the help of this forum and a past DIY post....only took 2 hours. The car is still not going into reverse, it makes the sound and jerks a little like it is engaging, but it feels like it is in neutral and you hear a little rattling. The car will shift into neutral which seems to work fine, and the car will move in all the other gears. I took it out for a drive and after taking off after a couple of seconds, the car downshifts very harshly, and stalls...I did not try driving it too much because I know it cant be good for the trans, whats left of it.

I disconnected the battery while doing the switch, and now, the gear indicator in the dash does show the correct gear (not highlighted anymore), and I have a Actron OBDII reader that is not pulling any codes....I am at a loss as to what to try next....

The only thing I have gathered from previous posts is that perhaps my OBDII scanner is not able to clear codes and that a VAG com is needed to clear any old codes that might be stored in the cars computer??? I have a vag com cable on order, and hope to get it soon, Im hoping that might shed some light.

The other thing I have found from my extensive searches of this and other forums is that it could be the TCM???? which is somewhere on the passenger side footwell. Is it possible for the TCM to create trans problems like this?

Well, I guess that is it...sorry for the length of the email, but I wanted to try to answer any questions that someone trying to help might have.

Any and all help is appreciated. Thanks.

 

how's your trans fluid?

 

I was unable to find the trans dip stick. Is this a sealed tranny? How do I check the fluid?

 

there's a fill hole... i think on the passenger side. i'm sure there's a diy floating around somewhere for that trans.

 

ok maybe not? i thought there was, tried to find a diy didn't find anything. maybe somebody else can tell you whats up. i just remember on another car i had, i couldn't go into reverse because the trans fluid was low and it couldn't build enough pressure.

 

I think I found something on how to check the fluid. It is difficult, especially for someone that doesnt have a nice lift. But it involves raising car, opening fill plug on side of tranny, and filling that with some type of pump till it pours out...but another post says that fluid should be hot.

I did find that the TCM is more of a common problem that could cause these issues Im having too....and it seems easy to get to and clean. Some have claimed that cleaning it fixes the problem sometimes without having to get a new TCM. Im going to try that tomorrow, and Ill post any updates...if I get brave enough again, Ill try to check the trans fluid level too, but im a little concerned about messing with it in case I over fill and cause more problems. I wish my vag com cable would get here! My OBDII scanner is not pulling any codes or freeze frame data at all...according to my scanner, the car is running 100%....piece of crap! :-)

 

It could very well,be your TCM. That is the best case scenario,worst case would be you have a mechanical issue with your trans,which means a tranny replace or rebuild.

I know from experience as i replaced my tranny on my 01 A4 AWM B5.

My tranny went in reverse fine,it was just it would not shift into 4th or 5th gear, only 1st,2nd and 3rd,whenever the TCM=transmission control module would tell the transmission to shift into 4th gear,the car would give a hard jerk and kick back down to 3rd gear. I tried replacing the TCM in hopes,that would be my issue and fix it but to my dismay,after taking it to an Audi stealership,i discovered that indeed,there was a mechanical issue and my tranny needed to be repaired/replaced.

It's been a year since my tranny has been replaced on March 23, 2011 and it shifts smooth as butter,tranny was got for 1,000.00 with 70.000 miles on it and was installed for 400.00 plus fluids and tranny filter.

I paid 5,300.00 for my 01 A4 B5,so i felt a need to invest in getting it fixed,rather than loose my investment so soon after i purchased it just 5 months before the tranny failed.

So you just have to ask yourself,is it worth repairing? How much did you pay for it and does the cost of repairing it,exceed the amount you paid for it?

My situation was a no brainer,1,580.00 to fix a car i paid 5,300.00 for...

 

It might not be a bad idea to lift up the carpet on the passenger side front & see if there is any water down there. If there is remove the black box that contains the TCM & dry it out.
If there is green fuzzy **** on the connector you will probably need a new module & some connectors.

 

my tcm went out when i got stuck in a flood, went into limp mode, only gears 1-3. got a used one from shoken or whatever that place is in upstate ny the audi salvage yard

 

I went in an was able to pull the TCM (who at Audi thought putting the TCM there was a good idea by the way? One Big Gulp will knock it out)... and it looks like it is in pretty good shape. When I took it off the harness, it did have that burnt plastic smell, however. Last time I remember smelling that was on my 84 Volvo which was my engine harness melting into one ugly smoldering mess.

The part no. is 8DO 927 156 BM, and from the quick search on eBay, I can get one for around 100 bucks. But Ive already thrown 100 on the neutral switch, which it could have needed anyway, and it gave me a chance to seal it off from future issues with zip ties and silicone as suggested, but I hate to throw another Benjamin at it just to find out the trans is shot.

Just for kicks, I tried the car with the TCM disconnected to see if it would shift ok as one poster recommended. What I found was that the car acted exactly the same (no reverse, car would shift into drive 4,3,2, and 1 and move) No lights in the display, and no foot on brake lighting up. Also, I did not need to press brake to shift between any of the gears. I have no idea what this is telling me other than that perhaps the TCM is not the problem??? Im not sure.

Almost forgot, running w/o TCM connected finally did trigger a code: P01613.