My Xj308 3.2 2001 117000 miles and fsh. is new to me. Its lovely for about 20 minutes then has an electrical brainstorm...
The error message "low brake fluid ,acs unavailable,gearbox fault,then restricted performance mode comes up in sequence....followed by the speedometer rev counter and temp gauge saying goodbye...the car seems to work perfectly as the gremlins have fun...! Left overnight the messages dissapear to return after another random time gap!
Have taken car to garage and autoelectritian to look for error codes but non are recorded! Does the forum know of an electrical magician in west wales or have had a similar sequence pointing to one of the components involved...seems odd as it seems to imply the acs/abs/gearbox and instrument computers are all ganging up! Appart from these above the car is in remarkably good condition and seems a shame to give up on the old girl....

 

I've had similar problems with my 308. Usually these issues happen at hot temperatures for me. Never had any in cool temperatures. I think our 308's have a sensitivity to hot weather. Although; I have not found any proof to back this up besides mine. I would check to see if your battery is charging, and is in more than good condition. I've heard these problems happening when the battery is on it's way out.

Hope you find the problem!

- Pilotman

 

Bad battery, bad grounds (earths).

 

Check both battery cables and make sure they have a good clean and tight connection and check the ground wire where it meets the trunk and also the main engine ground wire under the right side of the engine. There are more power/ground connections, but start at the battery first.

 

I also forgot to add that after your random 20 minute drive shut off, if..... let's say you do go straight to the battery and the positive terminal is very hot.... Well, the reason it's hot is either because the terminal has some form of corrosion between the battery and cable or the cable was loose and excessive movement and/or vibration was enough to make it arc on a microscopic level until the excessive heat ramped up the electrical resistance and loose contact until it cools down.

 

I had a similar reaction with my XJ. At one poiint I thought the alternator was on its way out. Ordered a new one and when to start the change out found the main wire terminal loos on the alternator and it had been arcing. Cleaned, tightened terminal and returned the new alternator.

 

I'd agree with Jhartz, these cars are known to do some very strange things when the battery is low. Anything from all kinds of warning lights (ABS fault, gearbox fault, etc) to the transmission not coming out of park.
I'd start by replacing the battery with a GOOD battery (eg. Duralast Gold for me). And make sure all terminals are tight. If these does not solve the issue, then it is likely a corroded earth terminal somewhere in the vehicle. I'd start with the battery and go from there.

 

Yep. The battery, power wires and ground straps are easy to rule out (and quite possibley the root cause). After that, you will be looking for CAN bus failures or bad CAN modules which are a much more difficult troubleshooting effort.

 

thank you ..new battery but ill see if the alternator is charging properly...west wales has a record for many castles but hot weather is a rarety thank you for the reply!

 

thank you ..new best quality battery £150 . ill get the garage to check the main earths next. I think there was once transient can bus error code so ill keep you guys informed...at least now i have a plan, ill work through your suggestions and see if we come up trumps!

 

I didn't pay that for an OE Varta battery from my Jaguar Dealer!

Add the battery cable connection to the HP Protection Module (item 5) to your check list:


(click on the image to enlarge it)

On the X308 and several other Jaguar models, these are known to come loose or even break at the terminal causing odd electrical faults.

Graham

 

Can I suggest Battery Megastore, Car Battery - Car Batteries - Battery Megastore. £150 seems way over the top for a good battery.