I just bought a 99 sovereign 4.0 v8 auto drove it 50 miles home, showed it off to my mate, and now all it does is dip into failsafe mode and gurgle along at 20mph every time I re start it.
Can it be the faulty front indicator tripped the failsafe mode?
Can it be the brake switch ?
Can it be something else?
Can it be that I was done?
Can it be that all Jags seem to suffer from too much technical sophistication?
please tell me the answer is dead simple!

 

The simple answer is to get someone to read the codes and start from there. I sure hope you weren't "done," that's just sooo wrong! Good luck. If you get the codes, post 'em and someone can tell you what to do.

Mike

BTW welcome to the forum, lots of great info here.

 

Welcome to the forum Londonroader,

Good to have you here with us at Jaguar forums.

Presumably this was a private sale with no warranty? If you have no come-back against the vendor, you need to get a code reader on it to find out exactly what is happening.

Follow this link XJ ( X308 ) XJ8 / XJR - Jaguar Forums - Jaguar Enthusiasts Forum to the X308 forum for help, advice and information. The 'HOW TO' thread at the top is a good place to start for info on regular issues.

Please remember to add vehicle details to your Signature to help others to give relevant advice. Go to the User CP button on the left of the top menu bar, then Settings & Options under Your Control Panel. Select Edit Signature and enter the details.

You can also visit the UK Region forum by following this link https://www.jaguarforums.com/forum/uk-68/ to find other members in this country.

Enjoy the forums.

Graham

 

welcome to the forum - plenty of info and support here so you can truly enjoy the drive. Hope you get the issue resolved soon

 

Thanks Graham,
the local dealer put in a battery on the basis that low (11.9!!) volts could trip the traction control - and thus failsafe/limp home (it was 2004 battery so seemed reasonable
Sitting in the waiting room i chanced to read a jaguar enthusiasts article about a 99 x8?? 4.0 with same prob and answer was some sort of vaccuum hose that had fallen off
I have read lots of stuff about throttle control bodies and brake switches all of which might be or might not be the prob
however the codes thrown out by the dealer are
p0121 throttle position sensor A circuit range /performance problem
and p1647 heated oxygen sensor control module bank 2 open/shorted and c1095 pump motor circuit failure, though these did not seem to excite them
Its back with them now after the new battery afforded me about half an hour of driving delight, and when I switched of and on again, the limp mode was back!!
can it be that modern mechanics dont trian on old cars?
Rod

 

Rod,

A weak battery can throw up all kinds of weird error codes on Jaguars. Here's the full extract from the Jaguar DTC Listing for the codes you have:


The Default Action / Possible Causes columns on the right show what to expect and where to start troubleshooting:

Did you notice P1000 or P1111? One of these is always stored. P1000 means the OnBoard Tests haven''t been completed since the last memory clear; P1111 indicates all OnBoard Tests completed.

If P1000 was recorded, it would suggest to PO had been having problems and cleared the codes to disguise this.

Graham

 

Thanks Mike,
The delaer reports that it seems its the throttle body (maybe),
after replacing the 2004 battery with a new one as low charge (1.9Volts) throws out the traction control system!!
I have found a bloke who can get me the right throttle body cheap apparently, and then there's the ABS to be worried about I am told , though in a wet patch on the road today I noticed ASC flash up as the ABS worked.
the codes thrown up by the way were
p0121throttle position sensor, p1647 oxygen sensor control, c1095 pump motor circuit failure
why are cars so fragile these days?
time was when you would drive round puffing out white smoke and with the CV joints rattling knowing full well what was wrong!

 

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Welcome to the forum Londonroader,

Good to have you with us.
Enjoy the forum.

If you haven't done so already you should add your car details to your signature to help others to help you.

 

thanks for all comments I found a local independent mechanic who checked codes and confirmed the failed lambda sensor though could not get the code for failed ABS console. We talked about it briefly and he confirmed that it's usually dodgy soldering to blame.
he fixed both and I am now purring along!
Not cheap,, but cheap is relative when it comes to quality.

 

Thanks for posting the outcome. Pleased to hear you're purring along again.

You'll find several threads about ABS module soldered joints causing problems. There's probably more info on this issue in XK8/XKR forum than there is in X308.

Graham