Hi,
I do not have a sport mode button that works and I have no illumination in th J-Gate on my car (not even the red LED to indicate the selector position.
I have read numerous posts regarding replacing bulbs etc, but since I have no illumination at all I was curious to know if this could be a fuse? does anybody know?
The dimmable illumination in the gauges works fine.
I have no light in the sport mode button, no red indicator that it is engaged (the cruise Control button works fine), and no sport mode response from the car.
Any suggestions?
It is a 1998 LHD convertible XK8 btw.

Thanks for you time,

Leif

 

the sport mode switch is a separate issue from the j-gate, perhaps someone knows how to replace the bulb. you will notice the difference most in part-throttle use. there may be a broken connection and the lack of illumination means that it is doing nothing.

there is an easy way to fix the j-gate illumination, buy a new one, actually there are re-manufactured units with a core charge additionally for about $100.00 less.

 

Has it not worked since you got the car? It sounds as if the previous owner possibly got in there and left connectors unplugged. I'd take the surround off and investigate.

 

Hi, i was in there yesterday to replace the jgate fascia. Checked and cleaned all the connectors and reassembled. Still no luck. I am pretty sure the sport mode button does not work as in the car does not respond to it at all, no change in revs, no first gear from a stand still. However I am having a problem with the torque converter clutch fixed soon, that may be causing the car to refuse to go in to sport mode.
on the jgate illumination I would very much like a link to a refurbished unit if anyone has a good source. The only ones I could find online were 4-500 pounds, and that was a bit much I thought.

 

Check if there is any transmission related OBD codes.
I did have rare P1601 on my XKR which caused no visible symptoms except there was no JGATE illumination at all (afaik transmission dropped so call factory safe mode). After cleaning both TCM & ECM connections I finally got rid of P1601 and voilá: JGATE is illuminated again.

 

I have a code related to the torque converter clutch that might be causing this. I am waiting for my garage to find time for me should be fixed soon. If I still have a problem after that I will continue to investigate thanks for the replies everyone.

 

I think you need a LJA6195BG :

SNG Barratt - The Ultimate Jaguar Parts Specialist

It's not listed as being for the 4.0 XK8 but if you cross-reference in the S N G Barrat catalogue, that's the number that comes up.

But - I went through a similar process as you are now doing, got the exchange refurbished item, and it didn't work. S N G Barratt were extremely good - refunded the payment immediately - and then tried to find out from Jaguar whether or not I had a faulty item, or whether there had been any software or hardware changes that might have been the issue. Didn't get a satisfactory reply from Jaguar, so I kept my old J Gate assembly and replaced the back-light bulbs. I appreciate that you don't have the red LED "position" lights either, so it's probably a different issue - I am just suggesting that if you go for the "exchange / refurbished" option, make sure it's OK before you send the old one back for the refund !!

If the

 

There's a DIY here if you want to try R&R yourself:
https://www.jaguarforums.com/forum/x...30/#post531164

M

 

Hi everybody,
thanks for the replies. I will wait to see if getting the torque converter error code fixed solves my issue before ordering a replacement part since I am missing the red leds as well I am hoping that getting all the codes sorted might for some reason cure the issue.
if it still persists I will have to have the module out again.
My current plan in that case is to test the bulbs and led's by applying power accross them from an adjustable output psu to find out if it is the bulbs/leds that are at fault, or the control signals for them before ordering a replacement.
I will update the thread with my results once I have them, but it will be three weeks untill the car goes in to the shop for repairs.

leif

 

As a data point, I believe the J-Gate is a "write only" CAN module. CAN messages are sent to it, and lights turn on and off. There is no direct electrical connection with the position of the actual shifter. So, your car could work just fine with this module "dead", I suppose, as long as it does not crash the CAN bus.

 

Hi, thanks for the ekstra information. The car runs fine except for the error code regarding the torque converter clutch circuit.
It would appear then that once the garage get the car fixed, if I still have no illumination in the j gate, I should start looking for the source of the control signals and fix that, assuming I can first confirm that the bulbs work.

thanks for the extra details

 

Not sure if this helps - and there were changes to the wiring in early cars but .....
the "gearshift illumination module" (J Gate PCB) has 2 x Green and Yellow wires which are the CAN in and out - they (as I understand it) switch the position LEDs on and off.
There will be a slate (grey) / black and black for the "not in park" microswitch, and a Red / Pink and black for the background illumination.
I think it's unlikely that the LEDs have failed - if they don't work, it's more likely to be a network problem, or something not working with the control circuits in the transmission like- as you surmise - the torque convertor clutch circuit.

 

Thanks for the ekstra info. Every little helps
so I M still at the plan of getting the gearbox fixed and then follow on from there.

thanks again everybody, will keep you updated

 

The 5 speed gear selectors are pretty common on eBay. The 6 speeds are much harder to find used.

 

So this one is finally solved. Turns out it was a broken Connection in the wiring harness from the TCM. Once this was fixed, Sport mode works, illumination is back in the J-Gate and the torque converter clutch error code is cleared

 

Congratulations Doogledee,

I too have a 98 and would like to file this away just in case it ever happens to me. Please remind me, what is TCM? Where was the break ( will help with dead reckoning)?

Thanks,

John

 

Hi John,
TCM is the Transmission Control Module.
the break in the cable was about 20 cm from the transmission en of the wiring loom between the TCM and the transmission.

 

Good catch by whoever found it!

 

Yes my Indie jag mechanic is a bit of a wizzard With these cars, he found the wire break eventually.
However the plot thickens a bit as my torque converter clutch stuck on error message is back.
However the J-gate illumination and sport mode still works, so it looks like I am having to seperate issues, one of which is fixed now.

 

What exactly is supposed to light up on the J Gate? The only light I have on the console is the sport mode light, which as of today is stuck on! I can't even see where gear position illumination should light up.