Hi,

First post here so be gentle on me! Posting from Scotland.....

I have a 1991 850i (M70) which I've had for 11 years and up until yesterday had been running just fine! I keep it well serviced etc.

On my way to work I came off a roundabout (Google it!) and felt a slight "judder" and "funny noise". I continued for about 500 yards at around 50mph when all of a sudden I lost "drive" completely and "AUTO TRANS FAIL SAFE" warning appeared. Fortunately the road was quiet and I managed to pull over safely. Turned off the engine and tried again - nothing. All I had was reverse gear, no forward gears! Used my Breakdown Recovery membership and had it towed to my garage of choice, who are unfortunately very busy and can't look at it until Monday!

It's not a snapped cable as I've had that before and the shift lever goes completely slack, slides up and down the gate with no resistance. There is still resisitance there, i.e. you need to "move" it into gear.

Obviously my first thoughts were of the dreaded gearbox/auto tramsmission problems and a very large bill. However on other cars I've had where the auto box has "gone" it's been a gradual thing, starting with "slips" or leaks then clunky changes and high revving and gradually worsening over a period of time. This fault seems to have been an instant one - hero to zero so to speak.

I pulled the dipstick and checked the fluid level and it seemed fine.

Is it likely to be a trashed auto box or something a bit less serious? Any help or advice would be very much appreciated.

When I first got my car and everything was in really rough shape I was driving on the highway and that message went up also... except my car just lost all power, stayed in second gear. I got the car towed home, I checked the fluid and everything was fine also. I took apart the shift gear area in the interior to find the mode switch (S, M, A) unplugged.

Ever since I plugged it back in the car has never done it again. I am not sure if that was the cause of the problem - but it has not occurred again.

TRANS FAIL SAFE can result from your car being in Limp Home Mode (LHM). This is caused when one side of the engine shuts down for any number of reasons. Best advice is to have someone hook up a BMW diagnostic computer and see what is going on here. Transmission is most likely not trashed.

TRANS FAIL SAFE can result from your car being in Limp Home Mode (LHM). This is caused when one side of the engine shuts down for any number of reasons. Best advice is to have someone hook up a BMW diagnostic computer and see what is going on here. Transmission is most likely not trashed.

Which also reminds me that was around the time when my engine also had problems with the right DK (throttle body) - and the car would go into limp mode from time to time back then... which could be a coincidence and I just thought it was the switch.

mine did this same thing.I changed the bateries.It went into lhm outside a auto parts shop. the bateries sorted the problems and got me home. the next day the same problem. turned out to be the alternator had handed it's notice in. low voltage on these cars cause funny problems.

I've had that problem but two new super-dooper Bosch batteries sorted it instantly. But this is not an engine/limp-mode problem, it is a automatic transmission problem.

N oforward gear "drive" at all.....

I had a trans issue on my 91 auto last summer. It started out where it never found 4th... then it wouldn't shift at all in 'auto' mode but would find 1-3 in 'manual' mode. Then I got the trans fail safe warning and the car wasn't really drivable.

The cure was cheap... new tranny filter and fluid flush (including flushing the converter. The trans now shifts better then the day I got the car. Its a cheap and easy thing to try before dropping the entire trans.

My understanding is that the new trans filters are designed differently so everyone should do the replacement.

Good luck,

-JRW

Hi,

First post here so be gentle on me! Posting from Scotland.....

I have a 1991 850i (M70) which I've had for 11 years and up until yesterday had been running just fine! I keep it well serviced etc.

On my way to work I came off a roundabout (Google it!) and felt a slight "judder" and "funny noise". I continued for about 500 yards at around 50mph when all of a sudden I lost "drive" completely and "AUTO TRANS FAIL SAFE" warning appeared. Fortunately the road was quiet and I managed to pull over safely. Turned off the engine and tried again - nothing. All I had was reverse gear, no forward gears! Used my Breakdown Recovery membership and had it towed to my garage of choice, who are unfortunately very busy and can't look at it until Monday!

It's not a snapped cable as I've had that before and the shift lever goes completely slack, slides up and down the gate with no resistance. There is still resisitance there, i.e. you need to "move" it into gear.

Obviously my first thoughts were of the dreaded gearbox/auto tramsmission problems and a very large bill. However on other cars I've had where the auto box has "gone" it's been a gradual thing, starting with "slips" or leaks then clunky changes and high revving and gradually worsening over a period of time. This fault seems to have been an instant one - hero to zero so to speak.

I pulled the dipstick and checked the fluid level and it seemed fine.

Is it likely to be a trashed auto box or something a bit less serious? Any help or advice would be very much appreciated.

I heared the OBC can give out the voltage reading. not sure what buttons to press. but someone here will know.
outher than that a multimeter on the terminals under the bonnet.

I was told that u need to deplete half of the tranny fluid run the engine a few moments than off and do the rest. What is the deal.

I was told that u need to deplete half of the tranny fluid run the engine a few moments than off and do the rest. What is the deal.

Read this post may not be related to transmission

http://forums.roadfly.com/forums/bmw/bmw-8-series-e31/9298523-1.html

This is exactly the same thing that's going on with my car right now. Does anyone know what was problem?

lol Thats my post on RoadFly. Be careful here...mine is an 840. Engine and trans are different, than what OP has. Hes got a tranny problem of some sort I think. I had all gears...so it wasnt a tranny problem.

We really cant figure this out more unless we get codes read.

But Im guessing at Trans switch harness under car on trans, or the EGS module failure some how. Bad ground. Something trans related.

Possibly the EGS box in the trunk near the passenger side battery. Not sure about the noise you heard tho.