I have seen other threads on this subject, but I can never seem to find an old thread when I need one☹️
I have a 98 XJ8 Vanden Plas and the cruise control is doing the “wngine failsafe mode” thing about 15 seconds after I engage it.
I replaced the brake switch, and no improvement. I remember seeing a thread on a vacuum tube? Location where under hood, and any other suggestions?
Have hard reset already.
many thanks!

 

One thing to check is pg 28 of this TSB.... http://www.jagrepair.com/images/TSB/...Flowcharts.pdf

Not sure if this will help, but give it a go... https://www.autoreservejaguar.com/ja...-actuator.html

 

There’s 2 vacuum tanks under the air filter base that has a plastic tube going to it from the throttle body and 3 VSV’s located under the black lid on the drivers side of the engine bay. Check this make sure it’s all hooked up first.

 

I finally had a chance today to look under that black box on the drivers side. Bingo. There was a vacuum tube that wasn’t hooked up. All god, thanks to your direction. Many thanks sir!

 

Hi 3timejag, not sure if this can help, but I fittyed Cruise Control to a XJ8 Sport, and it worked perfectyly..

 

Sorry.. dodgy keyboard lol

 

This is exactly what I needed, someone else explained it to me and I have since repaired it! This is a great reference picture though, first one I’ve seen. Going to save it and maybe I can help someone out at some point too. Many thanks man

 

😂👍

 

Glad it helped and you can make use of it, took me an age to draw that in Word... lol
Paul

 

😂👍 great job!