97 A4 2.8 quattro Automatic 122k
Ok, so here's the deal. The other day I went to put my car in reverse just after starting it up and there wasn't anything there. All of the gears were backlit,except the R. Well i managed to get the car in postion to drive forward and took it to the shop that I had the transmission rebuilt at about 2000 mi ago, thinking, no prob,, it's under warranty. WRONG (they said that it doesn't cover electrical issues)
They called the next day and said they managed to get the reverse to come back, but that I needed a Neutral Safety Switch and that they are $500 fom the dealer. I can't afford that on unemployment, so I found a guy on fleabay selling a transmission and he agreed to pull the NSS for me. He said the transmission was good in the car and that he was driving it up until the day of having the tranny pulled, the car had been in an accident and was totalled out...
Well i got the part and had the shop put it in and that didn't change anything. They said that it must be a bad part. i think that it must be something else that is wrong with the car. Could it be a mechanical issue causing the gears to be lit up? Is it a Transmission Control Module? A range selector switch? Corroded wires? I know that the carpet has gotton wet before from rain, so maybe the TCM is bad? But would the car drive if it were? And it hadn't been wet anytime recently...
i can't afford to keep throwing money at this problem troubleshooting when the labor fees alone are killing me. Does anyone know of a place that will take a TCM or NSS back, if it wasn't the right part?
It seems like I'm not getting overdrive since it's at 3000 rpm at 60 mph, where it used to be at about 2000 rpm and the 1st gear doesn't even show up anymore. I'm also getting horrible gas mileage( limp mode or poor gear range?)
Any help will be greatly appreciated!!!
Also, I'm in Dallas, if anyone could refer me to a good shop in the area.
Thanks!

 

Definitely start with things like the TCM. Have the shop test it and go from there.

 

will there be error codes indicating which sensor it is? They have used a scanner, but I assume that it isn't very specific because they obviously don't know what the problem is exactly.
thanks!

 

Well I don't know if the TCM will show up in a scan. Electrical gremlins are weird, also some things don't show up in an OBD scan, such as ABS issues. ABS systems need their own scanner sometimes.

 

I bought my '98 2.8 automatic already in limp mode and just got done troubleshooting it. When inspecting my neutral safety switch (or multifunction switch as it is also called) I found that the plug for it was full of oil because my timing belt cover is leaking. I also found that the wires between the plug and the TCM were melted and shorted together near the plug. So I cleaned up the plug and added some dielectric grease to it. I spliced new wire into the shorted section. While I was waiting to get the codes cleared I also took apart the console and checked the magnets by the shifter. They had a lot of metal shavings stuck to them for some reason so I cleaned them up and put them back. I also found that one of the fuses for the transmission was blown, which probably happened because of the wires being shorted. After I did all of that, I was finally able to get my car out of limp mode. From researching and my own experience, the first thing to check would be the plug for the NSS. Corrosion seems to be a common issue. If the NSS you got was working when it was removed, I doubt it is bad. Check for any blown fuses. There are about 3 that have to do with the transmission, according to the manual. You could check the TCM and see if it shows any signs of having been wet. It is under the carpet on the passenger front floorboard right under where your feet would be. It is in a plastic case that should protect it from the elements. If that doesn't do it, you could use a meter to check the plug for the NSS to see if there is continuity between any of the wires. I only checked the side of the plug that goes to the TCM since that's the side my short was on. When I checked mine before fixing my short, I had about 5 or 6 wires that had continuity. After I spliced in new wires, I only had 2 that had continuity. From there, I'm not sure what you should do next. From researching the issue online, it seems like most people who replace their TCM find out that that wasn't the problem. From reading part of the factory service manual that I downloaded, it says that if all of your gears are lit up in the instrument cluster that your TCM is active but in limp mode. So if your TCM is active, I would think that it is okay. Mine had all of the gears lit up when it was in limp mode. Also, you have to have the engine trouble codes cleared everytime you try something to see if it has fixed the problem. Even after I got my problem fixed, it didn't come out of limp mode until I had a scanner hooked up and the trouble codes cleared. I hope this has helped you out. I know when I was working on mine it was difficult to find information on it or how to fix it and it got frustrating at times.

 

When I had the car scanned with an OBDII scanner, it gave me several errors. My car has 240k miles and doesn't seem to have had much maintenance though. But the one important code I got as far as limp mode was P0705 "Transmission Range Sensor A Circuit (PRNDL Input)". Here's a link with some information on that code. They may have gotten this code and then told you you needed to replace the NSS. And once again, anytime you try something, clear the trouble codes to see if it has fixed the car.

 

thanks Jeckel, that's some good info!

 

Agreed - excellent info. OP, please follow up with your findings. The info posted so far, plus your results, would be a big help to others. If you can detail your steps and solution I'll sticky this or add it to the DIY forum to keep it handy for others.

 

Today I took the car to a VW Audi shop and they checked the car go codes and then cleared them. Well guess what? That took care of the problem and brought the car out of limp mode. The 1st shop that replaced the neutral position switch, didn't clear the code from the transmission control module because I guess they didn't have the correct scanner.....
Thanks for your help guys.
Case closed

 

I need some help with this too, I think i have the same problem
New 2nd hand good trans going fine two days later on open road drops a gear, no reverse, no over drive, all gears lite up on the dash and the car doesn't roll backwards in neutral, only when the car is not running. when using the gear selector to select lowest gear (2) dash displays 3... Do you think i may have the same problem as this? Ive taken the car into a service euro place, they cleared the errors, didn't say much, said i had a shot trans, put up on hoist, minor dent in the sump nothing major and maybe a tad over full on the oil but also another minor. I didnt get to see what the error codes were if any? still in limp mode maybe? or is it had it again after just two days? gears are smooth, no noises coming from trans, just the odd smell maybe from being in one gear though. no reverse or 4th. any feedback on this? thanks