Hi all, my Jag has recently started moving the seat to a very forward position when it’s unlocked. I have the steering wheel auto retract setting turned off, and I have memory programmed all three positions to my preferred location. The memory position never does anything though, I get the beep noise and the red LED but it never moves the seat.

So now when I unlock the car with my normal fob that I’ve used for months, the seat moves very far forward and tilts forward too. This is quite annoying. Any suggestions on how to stop it from moving every time I unlock the car?

I’m tempted to set it where I want it to be then pull a fuse so it can’t move anywhere!

 

You need to find and read all the TSBs for your car.
Jaguar issued diagnosis and remedies for many problems.

 

In Bob's suggestion of looking at the TSBs ............................

The memory positions are a stored position " value " in the form of X ( ? )

The value of X in this case may correspond to the extreme translate fwd and tilt positions

This X has gone bonkers and needs to be reset in the process of pulling the battery positive cable off for at least 10 seconds and then X is reestablished as a physical seat position as you assign it again manually

Observe the VIN 768225 in the TBS is around a late 1996 model

There may be a way to reverse current natural drain ( positive battery post removal only does not do this ) the memory to reset to zero state . will have to look at diagrams or someone may have already ventured into this area and is more knowledgeable

The good news is the system ( by your lights , chirps and movement ) is not dead , just wrong in a way

Basically, to reverse current natural drain would be to have the positive voltage sources drain with a " lead " to an electron " well " or full earth ground

This would be the dedicated module fuses as a whole module approach or a component inside the module that stores the X value

Would have to determine which fuse or fuses is hot at all times and this can be done by the " Hard Reset " procedure

On all X300 fuse boxes fuses # 1 - # 9 are hot at all times , fuse 10 , 12 , 14 , 16 require the small king relay in the corner of the fuse box to close to be hot , which leaves the remaining fuses to be hot at all times

There is a precaution on the hard reset outside of USA models as this locks out the stereo head ( theft protection ) and would have to have the provided codes to reactivate the stereo head , I'm in the USA so I don't have this

On hard reset the longer drain the better like overnight

This does not affect the X300 Engine ECU on this model , but other manufactures / models it does

 

Worth a try as the FOB through the SLCU as it triggers events in the SEU defiantly is ( SLCU ) hot at all times fuse # 3 or # 4 Trunk

This Security Lock Control Unit can be " Hard Reset " with no SEU removal but in your case you have the stereo head precaution

You can use battery jumper cables to bring both the positive and negative car cables together ( jumper ) , place a shop towel or cardboard on the exposed battery posts

The longer the drain the better

There have been reports of the SLCU connectors getting water in them from recent weather ( rain or snow ) and the water drain line clogged in the fuel fill cap well as the well drips on the connectors located underneath the well

In these SLCU connectors reinstallation the battery positive cable must be removed , or you can squirrel up the SLCU logic steps ( hint )

 

Thanks for the tips, I’ve had a look through the TSBs and can’t find anything that matches my symptoms, but there a few things to do with the potentiometers.

I’ll do a battery off reset, that may help. I also saw somewhere about a way to reset the potentiometers by moving them all the way back and all the way forward in a certain way, so I might try that also. Chances are when I put the battery back on something else will be broken! I’ve got the stereo code so that’s not a problem.

 

memory seats are a common point of failure as there are som many things that can be the issue.

i currently do not have working memory seats in my car.
i think its the potentiometers.
if i put the car on auto mode it will slide the seat back for exit.
but when unlocking and getting back in it doesn't move forward.

there is no red light on my memory button.
when i push memory it will move the mirrors and the steering wheel but not the seat.
i have swapped the control module (tried two) and that hasn't helped.
i have a spare seat now i can try but the memory in that car doesn't work properly either. (slightly different symptoms)
the red light does com on the memory button but i can't use the switch pack from it as the window switches are busted in it.
i am hoping between the two cars i can fix it.

you symptoms sound similar to what that car does.
i don't have a fob for it. the memory buttons do nothing, however if i disconnect the battery when i reconnect it the seat slides all the way forward and the backrest goes full upright.

so i am hoping between the two seats at some point i can make a working one.

if you can work out what is going on with yours maybe it will help me also when i get to fixing mine

 

I replaced a bunch of seat position potentiometers in new car warranty at the dealer.
They were very 'pricey' and the labor was high for customer pay. (4 potentiometers and about $1200- $1500 per seat parts and labor)

Very few customer pay jobs as a result.

Even when ONE position sensor fails, the seat will not operate correctly.

 

There can be a map to draw as the seat connector on the seat side half to put a resistance meter on the sensors to be able to check that off

You can move the components of the seat ( would be easy to do ) to retest the sensors in a different position

The precaution is you have to be very accurate to only put the seat motor power ( you supply yourself ) not on a seat sensor

The back or forth motor directions is only reversing the power polarity ( + and - or - and + )

If a sensor is completely dead in any position you can test and see that without moving the seat component so that would be the first try before putting power to the component motor

See page 26

To know you are not putting power on the sensors , test for resistance as the motors as a group should be one same resistance value for each motor , test for resistance on the sensors as that group should be a different resistance value than the motors

jagrepair.com/images/AutoRepairPhotos/jagxj1996.pdf

 

Working as a start

Start collecting bread wire twisties to perform easier

There is already a problem in North American Specification and Rest of World

The rest of world connector map is missing in wiring guide , the work below is North American with different whole connector whole #

See page 160 vs. 163 of the wiring guide

 

yeah i can't recall exactly but at some point when i had my car at mechanic, he used the ids on it and read through and i think there were 2 potentiometer errors.....
i just really hope between the two i can make a good seat, but then there is also the time issue.... sounds like a job that i may need to spread over a few days taking seat in and out to be able to drive the car....

 

Taking the start on the seat side connector which fizzled out on my behalf and to find accurate document info ................

you can find your specific seat recourses to test with a resistance meter minus the IDG approach to know exactly the sensors flagged

On the other persons issue once the sensors issues are resolved maybe the logic of the whole system will behave.

 

For a 1995 Rest of World wiring guide , breaking down the individual wires to what component and see how it falls into a Rest of World connector map ( great if the same map )

So far the difference is the connector as a whole connector #

See page 139

jagxj1995.pdf (jagrepair.com)

Table :

Headrest / Motor SM1 - 11D and SM1- 12D
Sensor SM6 - 1D and SM6 - 2D

Squab Recline / Motor SM1 - 1D and SMI - 2D
Sensor SM6 - 1D and SM6 - 2D

Seat fore and aft / Motor SM1 - 7D and SM1 - 8D
Sensor SM6 - 1D and SM6 - 2D

Working

I can already see so far that all 5 sensors have the exact same 2 pins on the module so it is a multiplex digital system and not old school resistors ( 2 separate module pins for each sensor ) as represented pictorially as each sensing device wiper brush in the print , but they all join wires at a tie point

In a multiplex system without IDS interpretation , you wouldn't know a bad sensor's location ( digital address ) you are down to replacing a sensor and see how the whole system works , with 2 sensors bad this is even harder but can be accomplished

On passenger aircraft the seat ( stereo and overhead lights control ) connectors would most of the time be disturbed as they would run along the flooring so susceptible to passenger abuse ( hint )

Carrying on forward