Hiya folks,

I’m getting some odd faults, if anyone’s had the same thing I’d greatly appreciate knowing how ya fixed it? So here’s what’s happening:

Car was working perfect, cruise control intermittently stopped working with no error message, a few days later it happened again (after 10-20 minutes of running) but this time the dash displayed “cruise not available, check rear lights, I checked all lights and all are working perfect, next, (overnight) the battery went flat and engine wouldn’t start (obviously), the next day (without jumping) the car started first try, I went for a long drive to fill the battery, cruise control was working, after 10-20 minutes the cruise/lights error displayed again, I stopped, turned the engine off, and drove for a further 30 minutes with cruise control on and no errors.

It would seem to be a faulty brake switch, but I’ve also seen that the grounding in the rear lights can be an issue (cause of the flat battery?). So, seeing as replacing the brake switch is a monumental pain in the ***, would I be better off investigating the rear light grounds first? Or is that a dead-end?

Also, I do have a OBDII, but it’s not working right, I’m gona have a crack at that tonight.

Thanks loads for any advice!

2002 XKR 4.2 SC Coupé RHD

 

It's likely the brake switch. It's not that hard to replace and it can be repaired with cheap switches and basic soldering skills. The switch comes off the bracket, too, if you find it easier than dealing with putting that bracket back in place. The top screw of the switch body onto the bracket fits into a notch, so it can slide off once the bottom screw is removed. But there is no denying it is an uncomfortable job.

FWIW, one of the rear bulbs failed on my car recently, and the message was only something to the effect of checking the rear bulbs. There was no mention of the cruise control. When both messages show, it is typically the brake switch, which is a pretty common problem.

Best of luck, keep us posted.

 

It's most likely the switch, the check rear lights referring to the brake lights. There is a possibility the micro switches are not opening/closing properly because the switch body position needs adjusting. There is a thread relating to that on the forum, so you might try a search. The forum search is not very effective, so try using google.

If the switch is at fault, the two micro switches can be replaced, saving about $100. Maybe another member will supply the part numbers.

Your OBD scanner will probably not be able to read the relevant codes.

 

My wife's 2006 XK8 has displayed the "Check Rear Lights / Cruise Not Available" message twice during our 8+ years of ownership. Both times it was indeed due to a faulty brake pedal switch. The first time (October 2012), I purchased and installed a new brake pedal switch from Jaguar. The second time (November 2016), I had an EE friend replace the two substandard microswitches in the assembly with better ones. No issues since. This is a much better and more cost-effective solution than purchasing a new OEM switch....

 

Ugh... damit :-(

I have a background in electronics, so replacing the micro switches themselves won’t be a problem. Does anyone know the exact make/model/part number for the components? (just the micro switches, not the whole unit)

It looks like a horrible part to reach, is there a longer but easier route? Like removing dashboard parts?

Lastly, why do the guides say to have the brake pedal pressed down during removal, won’t that engage the switch mechanism and make it more difficult?

Thanks again folks! :-)

 

No, the switch is engaged as the brake pedal is at rest. The peg on the pedal stem disengages from the notch on the body of the switch as you press on the pedal. Pressing on the pedal moves the peg away from the switch body. That peg is what is in the way for most of this repair.

Once you get the part on hand, double check the slide/ratchet on the switch trigger. It needs to be properly adjusted once the new part is in place. If the trigger is too loose, the car will "think" your foot is always on the brakes, turn the brake light constantly on and refuse to shift up as you accelerate.

One strategy is to buy/get the new part installed to get the problem out of the way. Then take your time to repair the old part to keep on hand when this new part fails again a few years down the line...

 

Ahh, I see!

Excellent, thanks loads!

Just trying to track down a suitable pair of replacement micro switches now :-/

 

It looks like I got these from arrow.com

OMRON D2HWA211D

Should give you a place to start.

 

Perfect! I’ve just ordered two of those exact switches :-D

Thank yoo

 

It's not necessary to remove the whole assembly. Loosen the top 8mm nut, remove the bottom one, then work the switch pack out.

 

Right-o, all done, just thought I’d write up my experience:

So, I went down the route of replacing the two micro-switch components, and removing the whole bracket to do so.
I ordered two D2HW-A211D-ND from Digikey.com, remarkably they arrived in only four days from Minnesota to Scotland! And the switches themselves are very very similar to the originals, no adjustments to the mechanism were needed.
It was a horribly tight part to remove, something I hadn’t read anywhere else was that there are foam struts on ether side of the brake pedal, I had to slice the right side one with a razor across its middle in order to fit my hand up to the part, and tape it together after.
Next, replacing the switches: I was very disheartened when I tested the switches with my multimeter because there was absolutely nothing wrong with them, they both functioned perfectly with no faults, however, I did notice that when the mechanism was pressed the two switches did not click at the same time, one of the switches had an extra 0.5mm of travel before it clicked, so I assume that was the problem, because during that 0.5mm the switches would be telling the car that the brake is simultaneously on and off. So, new switches soldered in and they both click at the same time.
Now, putting the whole thing back in the car, this was an almighty pain, working blind you really have to focus, feel and picture where everything is. I used the fishing-line method which I cannot believe... actually really worked! But still fidgety as all hell.

Took it out for a drive and all is well, no errors etc.

Also, thanks loads to everyone that helped!

 

Well done. Keep in mind that if you eventually have to do it again, it is easier and faster as a two-person job....

 

OK, folks. My wifes 2006 XK8 just showed that display. My question is, what happens if I don't fix the brake pedal switch, other than the cruise control not working? The rear lights work fine

 

well, if you wanted to just live with it, I think it’d be ok.

My exact version of the fault was that the two switches had become out of sync, due to one of the switches wearing out, so I’d assume that would cause some errors in the ECU, but I don’t know what the long term effects of that would be.

I could not live without cruse control, I use it a lot! But that just me :-)

 

Thanks norfskate
My wife does not drive on the freeways so no problem. However, guess she needs to check the brake lights occasionally as it seems that POS switch controls both.
BTW, she hails from clan McClellan. Love Scotland and Outlander, but need closed caption to understand some of it.

 

No probs, let me know if you get stuck :-)

Ah, she’s a lowlander, they’re a smart, peaceful bunch, the McClelland clans motto is “think on”.

Also, aye, I tend to water-down my accent when I’m talking to the world, I’m providing my own closed captions :-P

 

I thought you were joking about the motto, but I looked at her tartan and that's what it says. I thought all Scottish motos would be like, "Kill, kill, and kill more", or "Off with their heads", or "Shove that stick up his ****".

 

haha, well my clans motto is “touch not the cat bot a glove”, which essentially means “don’t mess with us”, so you’re half right :-P