Bought an '07 XJ8 VDP a few weeks ago and one three occasions when I started the car I got a warning in the odometer window that the cruise control was not available. What causes that? If I turn off the car and turn it back on the warning goes away, but I still want to know why it happens and if there's something I can do to prevent it from happening again. Thanks.

 

Low battery voltage most likely. I had the same issue not long ago, take it for a good long drive or hook up a suitable battery tender. IIRC there was a thread on here somewhere about some tenders having a chance of causing electrical damage due to too high voltage

 

If you get that after only a day or so after you last used it then it's the classic symptom (on a 350) of a battery that has come to the end of its days.

Minders: the one that most 350 owners go for is a Ctek, indeed Jaguar themselves sell them but with 'Jaguar' written on them ... at twice the price.

 

I have used ctek for many years, I have three of them, brilliant conditioners in my opinion, as mentioned above they also make the units for Jaguar, Bentley, Rolls Royce and Aston martin, to name a few.

 

I have a gadget made by Zus Nonda that continuously monitors my battery voltage. Over the last 24 hours it ranged from 13.9 to 14.5 volts. Over the last few weeks it has stayed within 2% of 14.2 volts. Over these few weeks I've been using the A/C almost continuously and I use the headlights during daytime driving, too, so it seems as if that's a pretty good voltage, but maybe it should be higher?

Thanks all for your comments and I'd appreciate folks' reactions to my monitored measurements and whether an average of 14 volts is ok or not.

 

I would get your battery load tested.

 

+1 on that.

 

Apart from the battery there may be something else doing this, so it might be worth scanning for recorded fault codes.

 

Cruise uses the ABS sensors on the wheels to measure speed and one may have failed.

SDD if you have it will tell you which wheel or there is a U Tube video on how to test sensors.

 

Scans didn't show any problems with ABS sensors, but my battery voltage dropped precipitously to 11.6 so I'll look into that.

 

11.6 get a new battery, Deka makes as good, or in my opinion, better than any other battery, i've ever used.

 

The battery was low because I was doing lots of fiddling in the car with the key at Position 2 without starting the car. After a 45 minute drive it climbed to 13.8 volts and I suspect will go back to it's normal 14.2 - 14.5 range with the next long drive. Maybe I'll throw it on a charger. But I think the voltage is good. I'll still do a load test. BTW, I haven't gotten the Cruise Control not available warning in days. A weird glitch?

 

14.2-14.5 sounds like the alternator, not the battery.

 

Was the "Cruise Control Not Available" the only waning

IE did you get the xmas tree lights, loose the speedo ect as well?

Cheers
34by151

 

If I remember correctly, when a wheel sensor is misbehaving, you get ABS and/or traction control unavailable messages too.

 

My is doing exactly this. Where do I begin??

 

New battery is needed ASAP and check battery connections too

 

Battery is less than a year old. The negative terminal was really corroded so I just replaced it. ABS light is now gone, Speedo works, power steering works. But dsc unavailable and parking brake malfunction are still coming up?

 

As an update, I got that error msg. 3x within 2-3 weeks, but haven't gotten it anymore. The battery was low one day, but has returned to 14+ volts consistently since then. As I mentioned in my first post, when the warnings appeared, I'd shut off the car and start it again immediately and the warnings were gone. So I can only figure those few warnings were weird glitches. Thanks, though, for all the responses so if this happens again I'll know what to start testing. And good luck to Dooder with his similar problems.

 

Check the connections at the ABS module and if this fails to fix it pull the IC and do those.

If the IC looses signal to the ABS iot will go into XMAS light mode
The thing to look for is the loss of the spedo

Here is the TSB
http://www.jagrepair.com/images/TSB/...%20Cluster.pdf

However before doing that, if you have not done so already, upgrade headlamp earths.

Use a new M8 bolt next to to the old posts and swap the wires over
The ABS/DSC earths though the one behind headlamp on the fusebox side

Not sure if the TSB mentions it but check pins 9 through 12 on the Jgate as well

Finally if you run though this and it does not fix it then next steps are to
Run a new pair of wires between the ABS, Jgate and IC
Finally if this dies not fix it replace the Jgate module

Cheers
34by151