This is wierd. Before I dive into trying to fix it let me please run it by you in case you've seen it before:

Issue: Cruise control button (2 inches from Sport button on center console this 1998 xk8) While the LED functions normally, lights when button is up, goes out when depressed, but neither position disables cruise control.

Cruise works properly there is no safetly issue. For a few days I just thought it was "stuck on".

Today I turned off Sport mode button (LED works perfectly here too) and lost cruise control! A few pushes told the story. The Sport button now controls both sport on/off and cruise on/off. Thank God Sport is working OK. This is just trying to figure out how the Cruise control on/off "moved" to the sport button.

Guess this will be a headache if/when I ever want sport off but cruise on. On the other hand, like you I just want all to work as designed.

I've never been into the console yet and I've never seen a switch I'd hessitate disassembling but let me ask: maybe something else or obvious is going on. Have you ever heard of this?

Are the sport & cruise on the CAN network (not that that will help me much - this just is wierd).

Please let me know if you have any ideas to shoot/fix this one. Thanks!

 

Your problem is the brake micro switches.

The brake switch can cause all sorts of problems via its communications with the ECM. I do, personally, know that the brake switch issue will affect the cruise control and sport mode operation and give you strange messages.

 

Thanks Testpoint, guess it could be worse. I appreciate it, now I'll look up everything to do with the brake switch testing. From your message it sounds like there is more than 1 switch. Might you know how many there are while we are on this?

 

Here's the link to the replacement thread
There is only 1 Switch

 

The one switch has two contacts inside. One normally open, the other normally closed. When one or the other provides a less than expected contact closure the ECM does strange things.

 

Update: Folks Guess I got Lucky - I left the headlights on last night. Charged her up, reset the windows and went for a ride. Good news! The sports button no longer controls cruise control on/off. Cruise is back to normal. Admittedly I didn't check whether sports on/off worked yet, but I wanted to post this before I forgot. Someday someone may search for this issue. Guess sometimes it can be brake switch, sometimes a reset is needed.

Thanks again to all who took the time to help me plan to replace the brake switch, I'm sure I'll need that someday.