Hello all,

I've had some gremlins that seem to pertain to my brake light switch failing, though upon extensive reading of the issue in the forums, my issues don't seem to be completely consistent with the issues others have, so I am posting to see if anyone might suggest what else I might need to replace or fix.
I already have a new replacement brake light switch that will be going in the car soon. Granted I should have replaced it last year, but didn't have much time to work on my car, and the issue went away on its own for awhile, so I stopped thinking about it. Well, now my car is mad. lol.

Initially, last year, my brake switch was giving me the "Check rear lights" and "Cruise Not Available" warnings intermittently. Right now, I only intermittently have the "Cruise Not Available" warning that's started up again in the last month after being free of "symptoms" for about a year (Probably ~10 months but close enough).
However my additional symptom I've noticed is after I come to a complete stop such as at a traffic light and then resume driving, she will intermittently not down shift, so the car will rev fairly high (~3000 RPM, seems to be in 2nd or 3rd?), and the issue will resolve once I remove my foot from the throttle, and then tap the throttle a few times. This issue only happens after resuming driving after a full stop, not while driving or coasting, and I'll be driving in the automatic "D" drive mode, Sport mode being active or not doesn't make a difference.

Now, that issue only occurs when the "Cruise Not Available" message is NOT on the dash.
When the "Cruise Not Available" warning pops up, that issue COMPLETELY disappears, and the car will drive normally again.

This issue was also present 10 months ago, the last time my switch was acting up.
The only other issue I had last year, was my car going into restricted performance mode, and throwing Engine codes pertaining to the MAF sensor, which I resolved by cleaning the MAF sensor, throttle body, and replacing the air filter. I checked my filter the other day, and it looked nice and clean, so I don't think the "Revving" issue pertains to that, especially since it seems tied to the "Cruise" message, and I'm not getting the same engine code or restricted performance, but I could be wrong.

One other thing I've noticed was that during that 10 month period of a well behaved Jaguar, was when the brake petal was depressed, I'd hear an audible "click" noise in the gear box. On a whim today, I pressed my brake to replicate that noise, and noticed it is absent. Is there a switch in the gearbox that might be failing as well?

Thanks for the help in advance. Obviously, the brake switch will be replaced hopefully next week, and I'll report back if that solves all these problems. Figured I'd make a post in the case that it does not, given my abnormal symptoms.

 

Read your OBDII codes and report them here for further advice....

 

Not getting any OBDII codes from the car.
I only have a standard OBDII reader, and getting a more sophisticated diagnostic tool isn't an option at the moment if I need to be looking for more codes that the OBD reader won't show.

 

Without chassis codes it's just guesswork and you could spend many times what a diagnostic tool would cost by throwing parts at it.

 

^^ Yep....

I bet you have at least one C-code logged, but without knowing exactly which one(s), you have no way of knowing what to do next. Maintaining an XK8/XKR requires owning a scan tool that can at least read ABS codes, SRS codes, BCM codes, and Transmission codes. As these vehicles continue to age, being able to read these modules becomes increasingly important....