So looks like I have a transmission issue. Finally got the hoses repaired and installed, replaced the broken trans line. Could not get the fill plug out, so changed the transmission pan out to the bottom fill steel pan. Changed fluid and filter. Had a bad battery, so I got a new one of those.

Now when I start the car, put it in to any gear, it immediately throws a incorrect gear ratio code. Clear the codes, restart the car, comes back immediately as soon as it is put in to gear - car does move so it cannot be the clutches. Have talked with several folks and some think it could be a bad TCM.

I have been exploring reman TCM or valve body with TCM, but apparently unless I get one that is preprogrammed I then have to have the adaptations reset. Not sure anyone in my small city can do that, calling Monday. Would prefer not to have to invest in a complete transmission rebuild or replacement, although I could buy a relatively low mile transmission out of a wrecked car for probably less than $1000, but then I have the whole adaptations problem again.

If anyone has gone through this, or knows of a transmission expert who I could consult I would appreciate hearing more about your experience.

 

Not likely the TCM, much more likely something relating to the work just done (underfilled, bad connection, etc)

 

Car had a trans fault when I bought it. Highly unlikely to be fill level, checked twice, car level, plug out, engine running 32 degree 2nd time, 40 first time.

 

check rear abs sensors but normally those trigger a failsafe when you’re driving

 

Right, also no abs codes which are usually present if you have a sensor issue. My friend that works in powertrain at BMW suggested speed input sensor, but again these faults appear with zero movement of the car, as soon as it is placed in to gear. The car will move and drive, no abs or speed sensor codes when done so.

Codes are P0736 when put in reverse, P0731 when put in D.

 

Double check the trans connector and that it is properly seated. If the TCM was bad, you could actually still drive the car, it would just be stuck in one gear. This just happened to me where my TCM got fried but I could still move the car. A few years ago I did a pan drop/fluid change on my XJ and also did a trans connector sleeve change. On the first drive after this, I suddenly got a gearbox fault mid drive. It was stuck in one gear even after restart. I managed to limp back home and what did I find, the new sleeve wasn't completely seated (it was actually very hard to get it in right) so while everything looked connected, the TCM connector wasn't actually connected to the TCM. So, back to your situation, I would think that since even a bad TCM would go into a gear, maybe you haven't got the TCM connector in properly. If that isn't connected, it's like the trans isn't there, so it wouldn't go into gear. Don't know for sure, but it's my 2 cents!

 

Thanks for the suggestion, I will check that. I did not replace the sleeve because I no leaks, but it does not hurt to check. It makes sense it is an electronics issues and not mechanical because it happens as soon as the car is put in to gear, before moving. I am suspecting either a connection issue, a TCM issue, or a solenoid issue that controls all motion (open or short, and TCM can tell as soon a gear is engaged). Obviously sitting motionless it will not be the 2nd, 4rd, 4th, 5th or 6th solenoids. I am going to dig in to the manual a bit more today and start checking resistance on those.

 

You might have done this, but do you have access to jlr sdd to read the tcm and possibly reset the adaptations

 

I don't have the SDD, kinda dreading it frankly. I have a Delphi unit for the LR's that I have to jump through hoops on every time microsoft updates something already and not looking forward to another set I have to keep up with. Using a Foxwell NT510 and it will read tcm and do some adaptations, about to dig in a bit more and read the individual solenoids. At first glance they looked fine.

 

Might want to also check the mechanical shifter linkage on the side of the trans near the fill plug. Those nuts that hold the shift linkage to the trans have been known to back themselves off. Again, if they have, the car sees the shifter in say D, but the trans hasn't actually been shifted. Another possibility, when I was in the STR trans through my whole ordeal, I noticed that on the TCM, there is a slider piece that is connected to the mechanical shifter linkage (if you know what I mean) again, right near the fill plug (but on the inside). So when you change gears, it shifts to the right place for the trans, makes the computers happy, and then off we go! Is it possible that got disconnected/slide off/broken while you were doing your work? If you were messing around near the fill plug when the trans pan was dropped trying to get a stuck fill plug out, maybe you whacked this part and made it unhappy.

No idea if this would cause your problem, just spitballing here!

Just had one more thought. When you do shift into gear, do you feel the kinda 'womp' of it moving into gear? I know it can be hard to tell, but with both my STR and the SV8 you can tell it shifted into drive/park/reverse (very obvious on the STR since the new TCM as it is still learning). If you can't feel anything, try it with the parking brake off again. If still nothing, then maybe it is something mechanical like I mentioned above. If you can feel it do something, then most likely electrical since it is trying to get into gear.

 

Again, appreciate the suggestions, I will check everything. I didn't fool with the fill plug once the pan was off, the steel pan was a recommend upgrade to prevent leaks anyway, so I just went with it. I looked at the valve body a little but of course the inside of a transmission is always very clean.

 

Well, check that off the list then. Did you see my edit above about trying to see if you can 'feel' it go into gear? (added it while you were posting!)

 

What I can feel is the transmission engage and get ready to pull. Vehicle will move off and drive, it just slips sometimes. Works better if you throw it in to gear and move off quickly before it throws the code. Once it throws the code, immediately starts slipping. Very much like it cannot figure out which gear it is in.

 

If you want sdd let me know. It will be a stand alone version with no updating. Of course it needs a vcm and a laptop to run on

 

Ya, at this point I would say you need IDS/SDD to see what is going on. Without the actual codes from the TCM it'll be hard/impossible to diagnose. If I were closer I'd be happy to help out as I have a few versions of IDS/SDD and a VCM, but, just a bit too far! As to the VCM, if all you are doing is pulling codes, I think a Mongoose (or even a clone in a pinch) would be fine. I'm thinking at this point it may be a mechatronics or actual clutch pack issue if it is slipping.

Just one last thought, how did you confirm the correct level of the trans fluid without using the fill hole? I could see an issue like this happening due to not enough fluid. Not doubting your work but I would double/triple check fluid level, but you need to get the fill plug our for that. Unless there is another way that I am unaware of.

 

If you would rather not go down the sdd path, the icarsoft jag specific is nice. You can access all modules. I have used it to see the trans solenoid pressures while driving among other things. I use the i930 model

 

Has anyone checked the PCM and TCM for moisture contamination?

 

By VCM you mean virtual machine running XP?

 

Codes are P0731 if you put it in D, P0736 if it is put in to R. This is without the car moving, foot firmly on the brake.

If you move off quickly before it has time to throw the code (very quickly) it will move off without slipping. If you sit there a minute and it throws the code it slips.

I swapped to the steel bottom fill RR pan, has a fill plug in the bottom with a stand pipe. The RR's don't have access to the side plug due to frame/tunnel restrictions.

 

I have the Foxwell NT510 with the Jag software. I can see the transmission module and read live data. It does show some solenoid values but displays them as amps, I assume that is due to the PWM signal. Your i930 shows as pressures? I have not dug in to the NT510 far enough yet, but I was hoping to be able to verify the solenoids. All of the techs I have spoken to so far have indicated the following:

1. Bad solenoids show up as a bad solenoid fault code
2. Solenoids will not indicate a fault until car is driven and needs to shift.
3. Speed sensors should not cause it to throw a fault until driven and there is a mismatch between expected speed and indicated. This goes for trans output speed sensor as well as ABS (although I have not checked any of those yet).

My next step is to dig in to the Foxwell data a bit deeper and see what I can active test versus read on transmission components.