Hello guys,
I decided to play in a snow bank yesterday. I was stuck and was rocking back and forth. Long story short, my transmission will now not engage in drive. Works fine in reverse, but no drive. Flashing S and M lights on the dash and flashing lights on the shifter in D, 1,2,3,. I am surprised that the tranny broke soo easy? Code was P0722 Any ideas. BTW, the dealership is about 4 hours away if I try it in reverse gear, and no telling how many police tickets. I also like to learn and fix things myself. Very competent at turning a wrench, but these electric cars I have little no experience with. There is no computer on any of my Triumphs. Other than reseating or swapping the XYZ switch, can I feel comfortable on long trips with this marvel of British design?
2002 Disco, 65000 miles
Thanks in advance,
Dog

 

Well Dog first I would check the trans fluid level and make sure it is still full and that you did not burn up the tranny by overheating it when you were rocking it.
Then I would check your battery and alternator voltage, low voltage will send the trans computer into limp mode, which is 3rd gear only, still driveable but slow starts and high rpm at speed.
If all of that checks out then I would have to say your XYZ switch got jacked up during your play time.
Also check your shift linkage and make sure it did not get bent.

 

Water in the wiring harness connector is a possibility. You can remove the center console pieces and clean the plugs out, grease them and put them back. Beyond that as you mentioned the x-y-z switch could be the problem.

It doesn't sound serious since you still have enough pressure in the gearbox to use reverse. And it's unlikely that all of the forward bands are shot or that the valve body is bad.

 

The P0722 is an output speed sensor signal failure. Basically, the ECU is able to detect input RPMs into the transmission but no output. Causes range from simple (the speed sensor itself) to a harness issue to a main problem with burnt drive clutches.

But, if your drive clutches are burnt and you had slipping, you should get code P0731.

 

Thanks Gentlemen. I am back home and have removed the XYZ switch, I will try to find one at a salvage yard tomorrow. The fluid was topped off, I am not in limp mode, I am getting nothing at all, engine just revs like it is in neutral, but will check my voltage and Battery in the morning. MY shift linkage has a slight bend in it, but looks like it was supposed to be that way, (ust checked a neighbors car, it is supposed to be that way) I will do the procedure in the rave manual to get it correct. I am stumped still, thanks for all your advice. Will not do anything forward, just reverse.

 

Any wya around this tool/ LRT-44-011, the one used to install your xyz switch or is it trial and error?

 

Well it is not the xyz switch. Looks like a tranni swap. fun fun

 

That sucks man.
Did the trans computer get wet?

 

I thought the trans computer was in the passenger cabin under the driver's seat? How would that get wet?

Also, what's the XYZ switch?

I'm going to get a shifter solenoid and maybe a XYZ switch from the dealer (if anyone knows of anyone cheaper; please share) in an attempt to get my Disco to shift out of Park. Brake position switch checks out OK.

 

do you have a disco 1?