This is my first post.
Some time back I was advised by a Jag mechanic that the problem with my seat/steering memory not working properly was due to a faulty Gearbox Rise mechanism as well as a faulty steering column tilt motor that doesn't work at all. The steering column reach motor as well as all the seat adjustment motors work just fine on manual. Spares were duly purchased but then I entered a lengthy period of illness during which my local Jag dealership closed. The Gearbox Rise is that which controls the height of the seat front.
Having removed the seat to have a look at the Gearbox Rise, replacement looks quite a complicated job and so, before I start breaking things, can anyone give me guidance on how to proceed.
As to the steering column tilt motor, everything I have read tells me to leave it to a Jag Dealer, this in the light of the danger of the airbag going off. Here again I would appreciate any guidance.
As to the general subject of seat memory problems, can anybody reassure me that I am heading in the right direction. The memory clearly works for certain items, mirrors, steering reach, headrest, and I accept of course that the tilt motor needs to be replaced. But is it logical that one gearbox rise will be the reason why the fore & aft movement of the seat as well as the seat height and back are not responding to the memory settings? Is it not more likely to be an electrical problem? When I remove the key the seat slides back but when the car is unlocked and the key inserted, it stays put.
Many thanks for reading all of this and for any assistance.
matade

 

Post a few more times to get to 10 and download the diagnostic TSBs.

bob gauff

 

Thank you v much Bob. I will now try and educate myself and revert.
matade

 

This is difficult!
When I started out it was against the background of a Jag mechanic having told me that I needed to change a gearbox. Unfortunately he is no longer available.
Logic tells me that if all the switches/motors are working on manual (except the steering tilt motor), the problem is electrical.
I have gone through the procedures outlined in 15-50 and it would seem that all the Potentiometers are responding as they should; the led by the Memory Button is illuminating as and when expected. I have seen a reference elsewhere that just one damaged Potentiometer will stop the system working properly but that doesn't appear to be my situation, as far as I can tell.
The check-lists in 501-35 confirm that the memory system is working as far as the mirrors, steering reach (obviously not tilt) and head restraint are concerned, but not for the seat itself. Given this, I understand that the memory system is working and that "the problem is therefore a mechanical or electrical problem with the affected axis, or a problem with one of the modules." As regards modules, I note that the driver's seat memory and also that for the head restraint are both stored in the driver's seat module; given that the head restraint is recalling it's position, does that suggest that the seat module is OK and the problem is elsewhere, ie mechanical after all or some other electrical issue, or is it possible for a module to partially fail?
The easy entrance/exit system works for steering column reach and the seat goes back for exit but doesn't return after entrance. Nor does anything move when the car is locked - it should return to normal position.
I have checked all the electrical connections within the seat itself so guess I now need to look elsewhere.
Is it possible that because the steering tilt motor is faulty the system will not work properly until it is replaced? So far I haven't found an answer to my concern re replacing the tilt motor and risking the airbag going off.
Finally, is my logic flawed and the original advice to change a gearbox indeed the answer! The box in question is the front seat height adjuster.
All ideas gratefully received.

 

The guided fault finding chart says to put each motor function to it's limit and see if the memory light works. If one sensor wiper goes off the sensor track, then that is the one that needs to be adjusted/replaced. I can't remember if WDS can be used on the X300 as a 'datalogger' to watch the sensors. I know it can for the X308. You might just have to remove the seat fasteners to displace the seat for access to the DSCM and use a DVOM to watch the sensors voltages as you reach each limit.

I have a WDS but I don't have an X300 in my shop right now to test.

bob gauff

 

Thanks Bob. Yes, I followed the fauilt finding chart you refer to and the memory light worked in every case.

Forgive my ignorance but what is a WDS? I am guessing a DVOM is a digital volatge meter and the DSCM is the Seat Memory Interface.

Do you feel that my problem is likely to be a potentiometer or something else, perhaps one of the issues I mentioned in my last post?

Again, many thanks. I appreciate the guidance.

 

WDS = Worldwide Diagnostic System or Software (The Jaguar computer from late 90s to 2006)

DVOM = Digital Volt/Ohm Meter

DSCM = Driver's Seat Control Module

Could be the DSCM but I don't know without testing things.

bob gauff

 

I got 2 right! Thanks Bob but it looks as though I am going to have to find a new Jaguar Dealer for this. In the meantime I will turn my attention to the steering tilt motor that I am also trying to educate myself about.

 

Managed to sort out my steering tilt motor problem and so am returning to the seat memory issue.

Focussing on the DSCM, I have learned elsewhere that it is not impossible to take these things apart to check for obvious problems. However, in my case the unit seems to be well and truly pressed together and I can see myself doing more harm than good if I use more force.

Has anybody any experience/advice about taking an X300 DSCM apart? The part no is LNA 2165 AD.

Many thanks.

 

I have not taken that module apart, but some of the jag modules are glued, requiring a jeweler's saw or such to split the seams. Just be careful to not saw too deep. Then use what we call "silicone sealant" to re-glue.

You made a statement in an earlier post that since certain functions were working, the module musr be OK. There are a number of different circuits in that module that have separate and shared components, but all work together . So, it is hard to define whichthings are or are not related.

I have seen seat modules for an X-300 on e-bay for $50.00.

 

I have a similar issue. Memory system works, but not auto entry/exit. Seat retreats fully, but leaves me a long way from the controls when I re-enter. As far as I recall, everything else that moves on exit returns, though I just leave that system off. Wheel tilted full-up is plenty generous for me to enter/exit, so I just set one of the memory buttons that way and punch it to exit. I had an unfortunate incident of my own making last week, but as soon as I return the x300 to service, I'll be happy to take it down to Bob's at a mutually convenient time so he can determine whether or not it responds as the x308. (I'll be there Mon. afternoon, but sans XJ as I need some parts from him to get it going again) It reported a covey of pot-codes on WDS when he had it hooked up nearly a year ago, but the function wasn't high enough on my list of "inconvenience/cost to repair" to document them. May not be the same as OP's, but auto entry acts the same.

 

Now that I have my steering tilt sorted, I am doing the same but apart from going fully back on exit, neither the seat nor the seat back respond to any memory recall requests. Steering is fine except that it doesn't move back from the exit position when the car is locked; I recall that it used to always return to a memory position. Mirrors and headrest are fine.

I have no idea how the DSCM is organised but the more I think about it, surely this is the most likely source of my problem?

 

Thank you.

As to opening the case, I am getting a little movement as I try to lever the halves apart (perhaps suggesting that they are not glued around the edge) but the fixing is clearly very tight and as the plastic is quite soft, my levers are just damaging the edges. My fear is that I will break the case if I use too much force.

Looking from the underside I can see that there are 5 rivet-like fixing points which u can also c from the top-side where they appear to be well inside the box. This suggests to me that these r the fixings for the circuit board inside and r not related to the two halves of the case but I could of course b totally wrong. On the other hand, again from the underside, there r another two holes where the top of + like plastic prongs(?) r visible. I am wondering if these r part of the top-side and r in fact the fixing points for the two halves.

My earlier comment was based on my reading of TSB 501-51 which suggested to me that if any part of the memory system was working, the fault probably lay elsewhere. I am no longer so comfortable with that interpretaion and am happy to be corrected.

I have started to look on eBay and elsewhere; thanks for the heads-up.

 

Hello. Iam a new member and find this site very interesting. I to have a seat memory problem in my 95. I just ordered a DSCM from a recycled shop that also
said that this unit from a 98 would work fine in my 95. I have not got it yet so I can
not say if it works. Is there someone out there than tell me if this is true?? I paid
45 for it. Looking froward to more interesting info here. Paul

 

Newheart, welcome to the forum! You may want to pm Motorcarman or Brutal. I don't know the answer but some of those modules have to be "introduced" to the car via WDS or something. Anyway, if you recieve it, swap it out, and it acts like it's not even there, that is probably one that needs to be intro'd.

 

Thanks so much for the info and will post to let you know if it works fine or not.
Paul

 

I believe the part no you require is the same as that for my 97 X300 ie LNA 2165 AD. This is an updated module from that which may have been originally fitted to your 95. Photos I have seen of the module for the X308 suggest a different part but others may be able to confirm. I suppose it is always possible that some 98 XJs used the same part. I have sent my module to www.bba-reman.com in the UK for diagnosis and repair as appropriate. If you go to their web-site you will see that they have a branch in Canada in case that proves useful. I am expecting feed-back in the next few days and will advise. Diagnosis is about gbp35 and repair is estimated at gbp100.

 

bba-reman telephoned to say that there appears to be a problem with my DSCM that will require deeper analysis. Accordingly they will be running further checks that may mean they will have the unit for a few more weeks! They have already had it since last Tuesday.

I suppose I could say that the good news is that we seem to be moving forward, but the bad news is that it is taking a time to confirm and get it sorted.

 

Hello Colin. thanks for the info. This used unit should be here latter this week. Will
let you know how it works.
Paul

 

Hello. Just to let everyone know I received my used part to put under my front
seat BUT the suppler sent the seat switch instead.. I am returning it back to TX
and will try again.