Have relied on this forum many times, always found a solution thanks to you all, now for my first post because I’m completely stumped!

Here’s the story:

We’ve owned this 2003 Discovery II for 4 years, first thing we did was install a rebuilt motor, since then any repairs have been minor… The transmission has NEVER given us a single issue.

Two weeks ago my wife was heading 4 hours from where we live to Escalante, UT, with a friend. She was driving as per usual around 70mph the entire drive. She says it was driving as nicely as ever. 1 hour from her destination, traveling up a hill, “it suddenly started revving like it was shifting up or down gears to go up the hill, and then M S started blinking on the dash and it felt like it was losing power… I immediately pulled over and shut it off. Then when I turned it on and put it in drive and tried to go, the M S and D started blinking and it did not move, it only revved. The SES light came on, and the code said P0722.” She did not use AC on that entire trip and it wasn’t raining, so no drippage in XYZ switch. We live in the desert, we don't take it wading.


A kind friend towed it the three hours back home on a trailer. I was not there, this is my wife’s account, so take it for what it is.


Back home, it became my problem.

My approach to Rover problems is straightforward… Visit the forums, find a similar problem, attempt the same solutions. A combination of knowledge, theory, and throwing parts at it. I love throwing parts at it.

But this time, nothing seems to be working. I’m hoping one of you can give me some insight, because yes, I will have this beast fixed and will be keeping it forever… Giving up is not an option, no matter what the solution looks like. I’m willing to install a replacement transmission, but on several similar leads, I’ve learned that isn’t often the solution… Can these transmissions simply “fail” without showing any prior symptoms? Doesn’t seem likely.

Here are the symptoms:

> No Gear Engagement

- By this I mean, putting it in drive, Neutral, 3rd, 2nd, first, and Reverse, does NOTHING, despite showing the correct gear on the dash (more on that later) and the engine changing rpms as normal when it would go in neutral (so it’s obviously communicating with engine ECU). Before the wife's fateful trip (this stuff always seems to happen to the wife, never me) there was always the feeling and slightly audible sound of it going into gear. None of that now. In any configuration of High and Low, Sport Mode, etc. Tried everything I could think of. 4lo and high have always worked fine as well.

> Blinking “M” “S” and “D” and P0722



Here’s the facts:

> The transmission has never given us any problems or hints of problems

> The fluid was full and clean… Regardless, I drained it and removed the drain pan to inspect for metal fragments. There was no more than the slight metal dust on the magnet. Really quite immaculate in its dashing red color, I was impressed. I refilled it with new fluid, new filter, and new gasket, and swapped out the speed sensor (that generates P0722 code) for a brand new one while I was in there. Same results… I couldn’t “top it off while working through gears” because it won’t work through gears.

> The battery, a 6 month old Interstate, tested good… 12.65 while off at time of test, 14.41 while running. Regardless, I tried it with two other good batteries. Same results.

> The alternator was working and tested well. Regardless, I bought a reman 130a Bosch unit, same results.

> The ground lead, and grounds (the ones I’m aware of, including battery terminal, post just behind the battery, engine, and driver’s side at rear of engine, were fine. I also checked the starter postive/negative leads. I also unhooked, cleaned, and reinstalled all of these grounds. Same result.

> I checked every fuse that seemed remotely related. Including #13 under the hood, #20, #21, and #25 under the steering wheel. All fine.

> I cleaned the MAF sensor, then, paranoid, replaced it with a brand new unit. Same results.

> Air filter is relatively new and clean paper one.

> For what it’s worth the 02 sensors were replaced a year ago

> The front drive shaft and the rear driveshaft flex-plate are not even a year old yet

> I inspected XYZ switch plug for dirt/corrosion… Again, immaculately clean. I cleaned it with electrical connection cleaner anyways. Same results.

> Next I removed the XYZ switch and opened it to inspect. Again, immaculately clean. I inspected the connections as best I could, but when I went to pull the unit further apart because the lower connections are not easily visible, the plastic posts they’re mounted on broke. Rats. I went to a friend (who has multiple DIIs and has fixed them for years) and pulled one off of a rig with a blown motor but working transmission.

When I installed this one, I now had no gear indications on the dash. Rats, another problem or part of the same problem? Removed, made sure both the switch and actuator post were turned maximum clockwise… reinstalled, now it wouldn’t even start! Wouldn’t allow the key to turn even. Kept fiddling with the switch. Took this one apart as well and inspected inside, clean. Not going to make the same mistake, checked the connections best I could, thoroughly cleaned with contact cleaner, riveted it back together, reinstalled. Now it let me start the motor, but wouldn’t indicate a gear until I had it in what would be first, it would finally briefly blink “D” and then M S and D would start blinking. Briefly it also started revving on its own over 1,000 rpms… I actually got out and toggled the throttle cable and it went back to normal idle. The throttle body was cleaned less than a year ago, and it's still clean. After each time fiddling with the ground cables, of course it resets the codes... When you rev it, the SES flicks back on with the same P0722 / Output Speed Sensor / Torque Converter code.

I would attempt the torque converter test, i.e., put it in Drive and rev it to see if it lags at 2k rpms, except it WONT GO IN DRIVE!

I inspected the transmission cables, under the driver’s seat components, etc for anything obviously out of place. Couldn’t find anything.


This is where I left it as I’ve determined I have no clue what’s going on.

Because there were never issues with the transmission, as in, no noises, vibration, gear changing problems, etc. My gut tells me it’s not mechanical. Something is telling me it’s electrical, but I’m tired of relying on these voices in my head.

I don’t have much experience with automatic transmissions, but I have rebuilt a manual tranny and am at least slightly above entry level mechanical knowledge of the auto, which is to say I know next to nothing, but anyways I’m stumped.



RAVE relates the P0722 Transmission Output Speed Sensor code to the torque convertor slipping. We haven’t had any symptoms of anything going awry with the torque convertor, so it seems it would have been a spontaneous failure that would result in the problem we’re having if that’s what it is…


Only KNOWN problem prior to this: Our rear main seal has had a slow leak for about a year now, but hardly enough to bring the engine oil low between 3k mile oil changes, which I am religious about. Along with driveshaft greasing. Dif fluids and t case fluids changed last year. For whatever this information is worth relative to this problem.


SO! I am now completely suspicious of my XYZ switch. I am prepared to pay the $600 for a new one, but if the problem is actually the transmission being “burnt up” then I’d rather invest that into replacing the transmission with another used unit (I have one lined up if that’s what it is).

To me it seems obvious that whatever is supposed to engage the gear selection you make via the shifter/XYZ switch, is not doing it.



For this reason I decided to last ditch turn all my findings over to you guys before I do ANYTHING.

 

I have a suggestion, you have a 2003 so I suspect no CDL. 1st thing always check RAVE P0722 flashing M & S + D you should still move, as you noted torque convertors do no generally fail all at once.

• Jack up up the Disco so the tires are off the ground you need all 4
• Transmission in neutral
• Spin a tire the drive shafts should spin, tires on both ends should spin if not you may have a transfer case issue
• Next drop that little round inspection plate on the bell housing see if anything comes out - nothing should but if you get any fluid that is bad sign

 

I would suggest that the first thing you try is to get your xyz switch correctly aligned. The problems seem to have started before you messed with that, and you say that the gears were being displayed correctly but now they aren't.
If you disconnect the xyz from the side of the transmission but leave it connected electrically, you should be able to rotate its central pivot and watch the display change on the dashboard. Engine doesn't have to be running, but the key does have to be on. Probably best to have someone inside the cabin to check.
Next, have your helper move the shift lever through the gears and watch the shaft that the xyz sits on, to see if it rotates as the selector moves.
If those two things happen, you should be able to reinstall the xyz and align it correctly so that you go back to having the correct selected gear displaying. At least that should eliminate one source of confusion.

 

Okay, I had marked the old unit but I could only eyeball the new one. I figured if it went on and the bolts lined up it should work, obviously not! I will fiddle with that shortly.

I should mention it goes into Park (won't move) and Neutral (can roll it).

But nothing else... No "3rd gear limp mode" no "Reverse" nothing.

 

How do you get from Park to Neutral without going through Reverse?

 

If by "going through reverse" you mean moving past it on the shifter column, of course it goes "through" reverse, but it doesn't go into reverse. In reverse, it does nothing. You can rev it, nothing. Even when it was showing R on the dash and the red light was indicating, nothing. But in Park it is immobilized and in Neutral it was loaded onto and off of the trailer.

 

Sure, but I'm only talking about the xyz switch and the physical movement of the rotating shaft that turns it. Don't even start the engine for this part.
Once you get your xyz alignment correct, then you start the actual diagnosis.

 

Okay so Dave Ashcroft, Ashcroft Transmissions, said that because it goes into Park and Neutral, the problem is not external but rather internal. Thus, it's looking like I will be going the route of replacing the transmission.

 

Sorry to hear that. I switched out a couple of transfer cases this past summer and that was a laborious job; I wouldn't fancy wrangling an entire transmission.

 

I pulled the tranny & the flex plate was in multiple pieces... Likely the culprit for no gears. Taking the opportunity to swap for an '04 unit with 04 t case