Well...here we go. Reasonably "new" 97 XK8. Had a mysterious but rarely ocurring issue shortly after purchase last fall wherein upon turning key off, motor remained running.. D]sappeared for months, came back the other day, then okay again. Suspected faulty ignition switch. NOW in garage,starts, however gear lever will not move from Park . Motor turns on and off normally. Can anyone offer suggestions? I suspect there is a relationship between ignition switch and gear release but??? ..not sure if that is true or not and if not, what the issue may be. Again most grateful for any mechanical Wizards out there thoughts/diagnostics ... THANKS! ,Daveyj

 

Sounds like the brake pedal/stop light switch is faulty.

 

Presumably you cannot hear the solenoid operating on the gearshift when you press the brake pedal? You can override the solenoid by removing the small torx-headed plug and using a small screwdriver but that really only a get-you-home measure.

Richard

 

Thanks MC. Yeah
I also realized there's a brake/shift relationship but issue coincidently occurred right after ignition fault so .. ?? That said I assumed there was also a brake/gear sensor somewhere which I've been looking of on youtube(no luck) Would you have any further details as to where/how to attack that potential fix. I'm not immune from giving it a go if it's reasonably accessable. Thanks

 

Thank you Richard...sadly my hearing isnt great anyway, but no discernable sound. And I did find the override port on youtube right after my post (which works). Atleast I can drive it. Hoping to locate the issue.. Brake sensor (per Motorcarman) so we'll see where that gets me. I would have to think it is a sensor. Was hoping for a fuse or relay. Not so muchthe fixing, its the diagnosis thats a problem

 

Do the BRAKE LIGHTS come on with the pedal?????????

 

Am I a bad person because, when something similar happened to me (I couldn't get the car back into park), I removed the entire broken shift lock solenoid assembly and decided I liked it better that way? Was that wrong? I hope not.

 

Greetings Davey,

From motorcarman's posts (#2 and #6) the Brake Pedal Position Switch (BPPS) contains two microswitches that control simultaneously, two independent circuits , , ,

• one activates all 3 brake lights (ie includes the rear window brake light;
• one activates the park interlock solenoid that inhibits the gear selector.

However, these are also dependent on "ignition ON" so if you are getting only intermittent power at the keyed ignition switch, coupled with park interlock failure, there could be an ignition switch failure . . . logically possible, but I suspect that you would see multiple other ignition dependent faults. Are there any?

If hearing impaired (like me) I recommend you get a helper blessed with good eyesight and even better hearing . . .

• key in, turn to ON but do not start . . . while helper listens at gear selector for the "click" of the solenoid;
• key in, turn to ON and depress brake pedal . . . while helper at rear reports if all 3 brake lights illuminate.

Where you go from there depends on result and your upside-down fitness if you contemplate DIY. Fix is eminently doable but, as I approach my 80th, far tougher than even 20 years ago. You could consult my thread from just 2 years ago as the X308 uses same BPPS as X100 . . .
<https://www.jaguarforums.com/forum/x...ctures-280881/>

Cheers and best wishes,

 

Kenneth(I think?) -- thank you ever so much for this savvy analysis. Interestingly, I now realize that the last thing I did a week or so prior was an attempt to replace a boot light.Got an LED and when I inserted it the light came on, then went out.. (and now both sides are out) I hadn't attempted to drive until yesterday when the problem then arose. Point being, could this possibly be a fuse issue? And do fuses coordinate with the switches or do they operate independently? (I'm not very techy obviously... but I'm very good at taking things apart..lol)) PS- Would you happen to know which of the fuse locations the boot lights run from?

Of course the ignition switch issue complicates things(why would it be easy). Again highly infrequent occurences but obviously exists. I guess although the powering on and off correctly(most of the time) that could still cause this issue(although it's a first).... Intermittence stinks!

And miraculously at 71 I can still crawl around pretty well. Okay I'm off to take a look at the lights/Solenoid with my trusty wife with the keen hearing and keener tongue(who will berate this purchase till the end of time).

Thank you so very much again for this (and anything you can add) and I'll report back asap.

PS2- I got this one owner 97 XK8 in "new" condition, (racing green convertible) for USD$ 5,500. How could I resist?

PS3- For 79 you're obviously still sharp as a tack!

.

 

aahhh ,,american ingenuity! Love it. Very likeminded and if you have any info on accessing solenoid that may very well be the solution in the end. Certainly a strong contender. (if you didnt see it I got this 97 xk8 green convertible in like new condition for $5,500 (w 37500 mi.) I did immed spend $4k to upgrade timing guides but hey, still not complaining. It is gorgeous. Now... out to that gear shift for some more diagnostics. And thanks very much for the mention and anything additionally you can provide.

Best ,DaveyJ (NY)

 

Okay...reporting back. The solenoid seems non functional ie. no noise upon initiation. All three brake lights are functional. Car is currently starting and turning off normally. If I can bother you again for your thoughts, very much appreciated....

 

The most likely issues would be the switch on the brake pedal, the fuse for that circuit (although failure of that probably affect other systems as well) or the solenoid itself.

I would check these in order of accessibility, so first check the fuse (probably fuse 16 in driver's side facia fusebox but check your Vehicle Care Manual) then check whether power is getting to the solenoid connector when the brake pedal is pressed. If power is getting to the solenoid, then it's the solenoid which needs replacing. If no power is reaching the solenoid, then it's the switch on the brake pedal which is faulty or needs adjusting.

Richard

 

Check also fuse F7 (15A) in the driver side fascia fusebox.

Coupe or convertible?

edit: just spotted earlier post

 

I did this as well, something like 8 years ago, and never looked back.

 

Its blatantly that brake switch. You should find a code stored for it, if I recall correctly, and your cruise control should also be on the fritz.

You will find an exhaustive (exhausting?) thread on the forum about replacing it, repairing it, etc, which makes it sound like a major operation, but my 2c are just replace the whole module and make sure you have a SECOND PERSON to do the job. Part number is LJB6420BB

Changing it on your own is a pain in the ****. Changing it with a friend makes it a doddle. Find someone young and flexible to climb into the footwell and then someone up top to undo and tighten the nuts up. Took us 10 minutes. No idea what all the fuss is about.

You'll hear plenty of criticism of Uro parts on this forum, my experience with them has been avoid anything suspension related, but the other Uro parts Ive fitted (touch wood) have been fine. Or you can go find a jaguar oem part for 3x the price. Ive seen a Lucas version too. Just google the part number.

https://www.rockauto.com/en/moreinfo...HGICUsXw%3D%3D

 

Greetings again Davey (and apologies that my travels have kept me away) . . .

A word of caution . . . please do fuse checks as advised, but I plead that you do not start by ripping out the BPPS or even ordering its replacement.

As asked by motorcarman, then myself, you have confirmed that at least one of the two BPPS microswitch controlled circuits is working perfectly . . . all brake lights are illuminating as they should. This confirms that the BPPS internal cam setup, rotation and actuation of the microswitches are all working as they should. Yes, it is possible that the other microswitch (gear selector Park position solenoid interlock) has failed, but there are more logical places to begin . . . again, let me refer you to your Wiring Diagram (Stickies here, or Gus' JagRepair.com) and another (related) thread of my write-up on the layout of the gear selector module . . .

<https://www.jaguarforums.com/forum/x...earbox-246896/>

Again it is of the X308 but your module is either identical or similar. You can ignore the initial stuff about ham-fisted auction staff and focus on the connectors to the Park position switch and the connector to solenoid. Repeat the ignition ON test but look for 12V that suddenly appears at each connector when you press brake pedal. Bottom line . . . it's possible (not probable) that you may need a new BPPS, but there are easier, far cheaper. and far more logical steps to begin.

Cheers and best wishes Davey,

 

Great TB --this is a tremendous help. I did see a video to that end and will pursue if need be. Still semi flexible and not a stranger to the end of a wrench(or spanner as you say in the UK).Hoping I don't have to go there but certainly something I (and a son (if I can find him)) can tackle pretty easily. Well back to fuse checking and additional testing to the end game.

Double cheers and keep you all posted

 

Thanks again Ken. A bit overwhelming but will ultimately digest and pursue , step by step, inch by inch and hopefully get to the promised land. Certainly plenty to digest , test and hopefully finally hopefully get to the bottom of it. Off to pull some fuses. (PS--I hadn;t mentioned that after blowing the boot lights,I've now found the wiper spray pump and interior lights are also out , so hoping for a fuse that also affects the solenoid. Seems logical anyway. Again very appreciated. DaveyJ

 

Gentlemen of the Jury... Well ,,, in the end it was, fortunately simply the 15a no 7 drivers side fuse(thank you Michael), (which I ultimately came to suspect once I remembered I had the boot lamp blow(upon attempting to use an LED)) a week prior (and had not driven thereafter (ergo did not initially connect the dots). But --- I wanted to thank all of you, ie, Richard, Ken, TB,Cat, MM, 2500 and all for some fantastic insights into the system in general. I definitely accrued some knowledge should ever I need to pursue those issues. Well its a sunny day here and off for a short drive, top down (and no screw driver)!

PS- And I'll stick with old world incandescent bulbs in the future!

Best to all , DaveyJ(NY)

 

Just an FYI, the Sylvania LED’s are polarity marked. Using those has helped me have trouble free installations.

below is just an example of the ones I used in the dash cluster. Red dot is the positive side:






Z