[Disco Drew]

I just purchased a 1999 Disco II knowing that it had transmission problems. The previous owner had a fender bender, but drove it home, let it sit for 6 months and then it would not go into drive. I thought that it may have leaked out the transmission fluid and it was just low, but I topped it off and it is a no go. I get a PO722 error code which is a 'Output Shaft Speed Sensor Circuit No Signal'. It goes into reverse fine, but no forward gears. I am used to GM, Ford, and Chrysler transmissions which usually have no reverse when the tranny is blown. I am not really familiar with a BMW transmission, so I was looking for some opinions if it is blown, or if there might be an electrical issue.
Thank you everyone, my first post! :wave:

 

[Disco Mike]

Download a free copy of the Rave Cd, shop manual, and you can find how to test and repair that problem.

 

[Disco Drew]

Thank you for the link Mike, I can't believe that I had not downloaded that before! I thought that I had, but it was just a crazy big wiring diagram. I hope that you do not think that I am copying your name, it's just a big joke between me and my daughter every time a Disco song comes on the radio. I have to do a little Saturday Night Fever jig for her and, well, having two Discovery's now it just seemed like the right name. Anyway, in the rave manual it says that the PO722 (22) code is 'Torque Converter Slipping'. Is that a Land Rover difference in the two code explanations? From my experience, if a torque converter blows it's vanes, it wouldn't move at all. The reverse seems to work great. It says 'Maintains current gear in low range, limp home mode in high range. Shift pressure to maximum, harsh gear shifts / engagement'. This truck doesn't even budge, however the rpm's do change when you shift it. Do you think their is any chance that it is the inhibitor switch? I would hate to change it out if it was something small, maybe it is shot. Anyway, thank you so much for all of your posts on the forums! I can't tell you how much I have learned from everyone before even joining. I'm also in Denver, maybe our paths will cross some day!

 

[MykD]

Drew, my Disco is pulling the same code, along with 721. the manual says 722 is the Torque Converter Slipping. Naturally, I would rather change one sensor, but has anyone figured this out? Is 722 the sensor or the torque converter slipping?

 

[Disco Mike]

722 is no signal from the speed sensor, not sure where you came up with a torque convertor.s

 

[MykD]

The D2 shop manual. Page 616.

 

[Disco Mike]

Well, it is wrong.

 

[General Lee Stupid]

Bump. any new development on this?

 

[taylorshann]

do you guys no where i can find a trans oil temp sensor for a 99 disc 2 obd coding bad sending unit cant find one anywhere for purchase.please help

 

[MykD]

New Development

Welp, after replacing that sensor, the fluid twice, and seeing no improvement in the transmisison, nor the return of any other gears than 3rd and R (limp home mode) I had my Disco2 towed to the guy who works on my wife's Bemmer. (It's a BMW tranny incase anyone reading this doens't know that. Well guess what? It's toast. Time for a new transmission. FML. While replacing that sensor "may" solve the problem, I have yet to read where anyone replaced it and it solved this problem. Fact is, when you get a 722, it's not normally just the sensor. That's coming from a guy who has worked on thousands of those trannies and had "no dog in the hunt" since the shop owner was doing me a favor and letting him look at it. His advice was to find someone to rebuild it, or find one with less then 25K on it. (SIGH)

 

[Disco Mike]

Don't rebuild it, to costly, consider calling Paul Grant, his number is listed below, and see what he has used. You will not find a ZF22 tranny like yours with less then 75,000, but if taken care of a good used one will last you a long time.