Hi! I already posted this problem earlier under a different title, but have more info now, and hoping for new insights.

After not driving my '95 beautiful xjs for two years, (I realize I shoudnt have waited that long) my gearbox is not shifting anymore.
I am able to put it in D and R, but it is stuck in Limp mode. the check engine and gearbox warning lights are on.
This problem occurred after a coolant leakage from the small hose between heater valve and valve head, in the rear of the engine.
To get home, I had to refill the coolant reservoir several times, so a lot of water had been spilled over the gearbox, while driving
After replacing the hose, the gearbox problem occurred.
User member Vee already helped me al lot with his suggestions, but I'm hoping somebody recognizes this problem.
So, out of nothing, my OBD app gives me five codes;



I think these electrical problems must be occurring because of the coolant leak. Would it be possible that somewhere some electronics or cables were shorted?
How come suddenly four electrical problems occur out of nowhere. I checked the trans connector underneath the car; it was oily, I cleaned it, no difference. also I checked if there are shorts between the pins from the connector, which there aren't. for a very short while I was able to clear the motor codes; engine light comes off, and trans light also, but only for half a second. then turns on again. I'd like too have a look at the other end of the trans cable; It goes inside, underneath the dashboard I guess.. where does this connect to? would this be a place the coolant could have come and shorted stuff?

Or, would it be feasible that after two years of standing still, the gearbox would show these kind of problems.?I did drive it for a day without issues, and it was buttery smooth, actually like new., it has 90000 miles, and I had it flushed three years ago. the oil is very clear, and there are no leakages as far is ai know of. the general condition of the car is very good. Only after the repair of the hose, this occurred. could I have forgotten something around that heater valve that would do this.

thanx a lot...

Pim

 

With so many codes and failures, all occurring at the same time, it is plausible that the TCM has somehow failed? It is in the trunk (assuming you have a convertible, like mine)

Easy to replace, relatively inexpensive to buy (used), and difficult to troubleshoot.

Unfortunately 2 of the codes refer to the solenoids locked inside the valve body. Seems strange that two solenoids would die at the same time. That’s why I suspect it would be something else?

TCM is the best place to start, after checking harness connection you’ve already checked.

 

hi Vee; I think indeed something like that is more feasible. I don't have a convertible; and don't know where my tcm is... maybe some coolant came into the TCM? That would make sense... do you know where it is in the coupe?

thanx, pim




QUOTE=Vee;2813470]With so many codes and failures, all occurring at the same time, it is plausible that the TCM has somehow failed? It is in the trunk (assuming you have a convertible, like mine)

Easy to replace, relatively inexpensive to buy (used), and difficult to troubleshoot.

Unfortunately 2 of the codes refer to the solenoids locked inside the valve body. Seems strange that two solenoids would die at the same time. That’s why I suspect it would be something else?

TCM is the best place to start, after checking harness connection you’ve already checked.[/QUOTE]

 

Pim,

With your description of the symptoms, it does seem very likely that it was caused by moisture contamination of one of the wiring plugs, either the rotary switch plug, or more likely, the transmission sleeve connector. It seems too much of a coincidence that either you would have simultaneous actual failures of the solenoid valves and a torque converter circuit. It also seems unlikely, to me, that the TCM would fail merely through spurious signals. The TCM on your Coupe is located by the Right Hand B-Post. I would also think it very unlikely that moisture would travel all the way along the wires and up to the TCM.

So, I'd still be minded to start disconnecting, drying and cleaning the wiring connectors first.

Good luck

Paul

 

hi paul, thanx for your response;

You are talking about either the rotary switch plug, or more likely, the transmission sleeve connector, i managed to clean and dry the round connector (with the red circle in the picture) going into the gearbox underneath; is this the rotary switch plug you are talking about? but which is the other one? where can i disconnect it? because i also expect something like this to be the issue.



thanx!

 

Hi Paul, today i had another look at the transmission sleeve connector, the round plug on the picture, i already cleaned it a couple of days ago, and i measured if there were any shorts between contacts, which there werent. on the rotary switch , there is no plug, the cable just goes into the switch. i followed the cable going into the car, and managed to find the tw0 connectors. they are placed underneath the carpet so not really easy to acces. i could try to measure if there are broken cables, but actually everything looked very good. the cable is dry and flexible,and the coloured wires are inside a black watersealed sleeve... so i dont expect any problems actually....

or were you talking about other connectors?

thanks, pim

 

I can't recall if the Transmission Warning Relay was checked? Its inside the drivers side knee bolster, top right purple relay? That relay gets fed by Fuse #7 - Red - 10A in the fuse panel in the passengers knee bolster....because it would make too much sense to put it where the relay is.

There's also a transmission power fuse at #21 - Red - 10A....although I assume that would have to be good. (Same fuse panel as the previously mentioned one)

 

Hi Vee, today i also pulled all fuses from left and right interior. they were all good. didnt check the relay, but how does one do that, check a relay?

thanks, pim

 

Typically you can pull the relay out and attach the correct two prongs to a 9v battery and hear the click.

In your case, I’m thinking we can simply swap the relays and see what happens. Now I’m not sure if there’s any difference between the purple relays and the blue ones, but I wonder if you can find another purple relay and simply swap them out?

I have to assume there’s some reason they went with different colors?

 

The Violet Relays tend to be 5-pole relays, using, 85, 86, 30, 87 & 87a. The power switches from 30-87a to move across to 30-87.

The Blue relays are only 4-pole relays using 85.86, 30 and 87. Power switches to open 30 to 87 when triggered.

The transmission power relay is a 4-pole relay. You need to swap to an equivalent relay if you think the relay may be at fault.

Cheers

Paul

 

Hi Paul!

thanx for your response; I checked to see if the relay is broken; can't really find out how to measure this.
when I pull it out and put back in while engine running; I don't hear a click. hen pulled out; there also no gearbox warning light anymore.
I measured the voltage from the poles from the plug going into the relay, middle is ground, top(30) and left are 14v, and right(86)from middle is 12 v, with engine running and in P. bottom one is not connected.
as Vee suggested; I supplied 12v to the individual three poles from relay (with middle one being 0), but can't get it to click. I dint simultaneously fed 12v to more than one pole, as the car does apparently.

when I clear codes with my OBD app. I do hear and feel the click in the relay. but it is one click, the gearbox and engine check light come off, but immediately the gearbox light is on again (0.1 sec later) . should this state that the relay is broken or on the contrary; there's still something else wrong?

thanx a lot...

Pim

 

Best way would be to swap out that relay….unfortunately the convertibles have six other violet relays…the coupes do not appear to have any.

I think it should be a rather straightforward 5pin relay that should be found in any auto parts store. eBay and Amazon will undoubtedly have them for even less.

I believe it’s a SPDT 40A 12V relay.

 

None of my solutions or suggestions would have any direct connection to the coolant issue….short of the coolant getting onto a wiring loom with some nicked wires, shorting something out? That’d be a stretch though.

Im just thinking of items that could be capable of throwing out what appears to be two solenoid failures in the transmission valve body. I would think the TCM would be the more likely culprit.

 

Pim,

The Warning light is being thrown by an output from the TCM via the TCM Warning Relay. It feels, therefore, that your TCM Warning Relay is possibly ok, and its related fuse.

Your fault codes are being thrown by the TCM based on the various signals to the TCM. You have nine inputs from your Transmission plug to your TCM. Three of those inputs relate to the solenoid valves in the gearbox. Check the continuity (and eliminate x-continuity) on all nine wires all the way from the transmission plug through to the TCM.

Part of the control of the TCM is via the TCM power relay, the blue 4-pole relay. Check that one and potentially swap it with another 4-pole blue relay.

The TCM power relay is also supported by Fuse 21, 10a red fuse in the right dash fuse panel. Check that prior to testing the Transmission power relay.

The wiring diagram is your bible. I'm sure you'll find the fault! My intuitive conclusion, based solely on you saying the problem happened when you lost a lot of coolant is still contamination of the wiring plug.

Good luck

Paul

 

Hi Paul and Vee, that was my thought also; measuring the wires. I've been trying to get to the TCM but that is terrible. I don't know how to remove the interior to get there. Do I remove the back seat and then the side panel on the passengers side? It looks like to get the back seat out I'd have to remove the upper side panel first? With the light in it? There's a round piece I can't get out. I think that holds the panel... and according to the manual the TCM relay should be above the rr wheel arch in the trunk but also can't find that... so im stuck right now. I'm afraid I'll ruin the interior if I continue now. Tried to find movies of people getting to the TCm

Above the light is impossible to remove without breaking it I guess
but no luck . Also nothing on the forum. Hope you can help again...!!

thanx, pim

 

Pim

You don't need to touch the top panel with the light. The rear 1/4 panel is easy to remove, just follow the section in the workshop manual.

Cheers

Paul

 

Hi Paul and Vee; i forgot that I had one lying around. unfortunately, it didn't say I had to remove the wooden panel to acces two screws to remove the doorpanel. maybe this is because my service manual is for the 3,6 and has a supplement for the 4.0 engine, but I guess the 95 model wasn't included yet.
Anyway. it indeed was very easy, when I did that. and I now know that the cable is working, there are no shorts or breaks; I have measured everyone of the 9 pins, and they all 'arrive' in the TCM. I couldn't measure the continuity of the rotating switch, because it has no plug.
I also found the TCM relay, switched it out without difference. so next thing is switching out the TCM I guess? or do you have any other suggestions...?

i noticed there are several versions of TCM's on eBay; mine is a LHE2400AE/001, is this 001 important? several other numbers are cheaply available, the 001 not really.

since it seems that the fault hasn't got to do with this particular wiring; could it be the fact that the car hasn't been driven for two years? That maybe the solenoids got stuck(only after the gearbox operated perfectly for a day) or is it typically that a TCM fails after not being used for a long time?? Or maybe the TPS got moist?

thanx again, Pim

 

As you already know, I had one solenoid in my transmission valve body die. It may have happened because I hadn’t changed my transmission fluid often enough? I’ll never know.

Losing two? Perhaps the long layover gummed something up in there? I would think transmission fluid would prevent that from happening.

The TCM would only have gone bad if the coolant created some kind of short. A failed TCM seems like a rather rare occurrence, not often reported around here.

On a bit of good news, I think 004 is the one you want for your x300. The 001 is for the XJS

http://jagrepair.com/images/TSB/X300...TC%20P1777.pdf

 

Hi Vee; thanx for your answer; so you don't think the most plausible reason for the malfunction is the TCM anymore? The codes say solenoid A and B, 'transmission control system electric' , and 'torque converter clutch electric'
so four codes out of nothing. Wires have been tested ok, both relays are ok. So now I guess either TCM or indeed the gearbox itself...!? But these four codes.... can't believe it. Since we are talking about my 95 XJS, and not the x300; I should look for the same TCM that is in there right now, the lhe2400ae/001and cannot use any other one.? This replacement info you sent is for x300 only I gues?

thanx pim

thanxQUOTE=Vee;2814510]As you already know, I had one solenoid in my transmission valve body die. It may have happened because I hadn’t changed my transmission fluid often enough? I’ll never know.

Losing two? Perhaps the long layover gummed something up in there? I would think transmission fluid would prevent that from happening.

The TCM would only have gone bad if the coolant created some kind of short. A failed TCM seems like a rather rare occurrence, not often reported around here.

On a bit of good news, I think 004 is the one you want for your x300. The 001 is for the XJS

http://jagrepair.com/images/TSB/X300...TC%20P1777.pdf[/QUOTE]

 

Pim,

I relaised you hadn't told us when you last changed teh transmission fluid. These boxes are very susceptible to clean fluid.

As a final throw of the dice, and because it's probably long overdue anyway, drain and change your transmission fluid. And do it four times with a good warmup and cycling of the selector multiple time times in between each drain. This is because you'll only drain between 2.6 & 3.2 litres of fluid each time, and there's 10 litres of fluid in the system including pipes and oil cooler. So you have to do it multiple times to get the bulk of dirty fluid out of the system.

I'd also suggest changing the filter. If so, do it after the second or third change.

It might just cure your problem before you start buying a new TCM!

And if you buy a filter, DO NOT buy the one that all the suppliers quote. It's the one part of the Jaguar parts system that is incorrect and all the suppliers now quote the wrong number. The correct part number is JLM664. DO NOT buy JLM2128. It will not fit!

Cheers

Paul