I recently bought a 2006 XJ8 and the message cruise not available message intermittently comes on. When the message is on the cruise doesn't work. Need help in diagnosing the problem. My father-in-law hooked up his computer diagnostic tool and no codes came up. Any help would be greatly appreciated. Thanks

 

Check to see if anything is blocking the adaptive sensor. It's in the bumper, driver's side lower. Mine got obscured by snow once and gave the same message.

 

That is a very common issue with the xk8-xkrs, and more than likely the brake pedal switch in the X350 is the same type. Its a DIY job, if you're inclined. Lots of threads in the xk8-xkr subforum area if you need instructions, pics, etc.

 

Well, my husband checked the battery and it was low, so he charged it up hoping it would take care of the cruise not available. But to no avail. On to the next possibility!

 

Thanks for the help, will keep you updated on the progress and what the problem actually was.

 

I would replace the battery.... I had the same issue and even after charging the battery overnight, I would still get the warning. These cars are extremely sensitive to voltage it seems. I got a new battery from one of those battery and tire place here in the US. It was about $150. They had it in stock... Apparently it's the same as for a popular Ford Truck!

 

I told my husband how you had charged the battery and you still got the problem, so you recommend replacing the battery. He is going to disconnect the battery and connect it back up and see if that fixes the problem. He said what do you do when you replace the battery, you disconnect the old one. He is reluctant to buy a new battery when the one we have is fine. Will keep you posted

 

Started the car this afternoon to run a few errands and the cruise not available message appears. The next 4 times starting the car the same thing. The last 2 times no message and the cruise is working. Will let you know if the message reappears. Every car seems to have it's own set of quirks, lol! :-)

 

Brake switch, i guarantee you.

 

You may be right, started it up this morning and sure enough cruise not available message is back. Will keep you posted on what is causing the problem Thanks

 

Just had the same issue with my '06 XJ8 @ 73k miles. The battery seemed to start the car fine but it tested bad so I replaced it. No more "Cruise Not Available" warning!

 

Our XJ8 doesn't have adaptive cruise control. Thanks

 

It wasn't the brake switch. My husband completely bypassed the switch and we still got the message. Thanks

 

My husband is coming to conclusion the battery is the problem. The car had been sitting for awhile before we bought it. Now my husband is wanting to see if the battery will hold a charge. If the battery has enough voltage the cruise not available message doesn't appear. If the voltage is too low it does. So it seems the system is voltage sensitive. My husband will replace the battery if it won't keep the voltage high enough, even if the car starts with no problem.

 

hope you're right about the battery, not trying to be a wiseguy, but its almost a given for the xk8 with those very symptoms you describe. Do I not sound like i know what I'm talking about?

BTW, the brake pedal switch is a two-piece part, with two microswitches inside it.

Bypassing, if by that you mean he grounded it the entire switch, i'm not sure that would have any effect on the cruise control operation. If I read something different about the switch assignments, I'll edit this thread.

 

Hey guys,

Some food for thought! My husband has been turning off the lights and climate control before starting the car and the cruise not available message hasn't been coming on. Hence the cruise has been working. Once the car starts up he turns on the lights and the climate controls and all is well. So we'll be keeping the current battery for how long who knows but since the problem is gone we don't care. Any thoughts?

 

Hmm... I think your cure is what I would call a work-a-round. You shouldn't have to turn off lights and CC to get something else on the car to work properly. Anyway, what do you mean, "turn off the lights" ? Do you mean turn off auto-lights on the switch ?

 

I guess you could call it a work-around. As long as it works Yes, I meant turn off the auto-lights switch.

 

I have been following this thread with interest as I have been suffering the same problem i.e.. cruise not available. Not a big deal really but I use the speed limiter on the local AFB where the mil police enforce the 25mph speed limit as if it was the eleventh commandment, this is the South after all. I thought I would give the lights and ac off before start a go. It works for me; in fact just the lights off (not auto) works. I agree its not the answer the battery is, but I can nurse the battery along a bit more. I checked the brake sw costs and found a huge difference in price: Amazon $43 to OPaddy $82 none of them OEM. CarParts in the UK sells them for 19GBP and its OEM.

 

Glad the thread has been helpful. By the way are you stationed at Kessler AFB? My dad was stationed there for 8 years when I was a kid and we lived in Gulfport.