jaguar xfs 3.0d 2011. I have checked the battery and it is at 12.23v and when engine running changing at 14.4v. I have just changed the battery monitoring module and still have the same fault. has anyone got any more idea's. Think it will have to have a vist to the dealer.

 

If it's charging at 14.4V for long enough yet fails to get over 12.23 then it's a bad battery.

 

Yep, the OEM battery on the XF tends to go wonky after four or five years and the only proper fix is a new battery, yours is probably around seven years old so well overdue for replacement. Plenty of threads and posts here about this and it's an easy DIY job.

 

Read my thread about how to remove the battery. If the bolt has rusted to the floor plate it is a pain to get out and the bolt might snap. I posted how to fix if that happens

 

Hi to all that have tried to help and thank you. But I am an electronics enginner and deal with electonics on a daily basis and I have checked all possable causes except those that should not cause this problem. What I did not mention earlyer was another minor fault which I had not noticed which was on the reversing camera the lines that show you where the wheels are going had gone missing. I could not believe that these could be linked which according to Jaguar it is not possable.so I thought I would have to let jaguar have ago to see if they could find it. After they told me to diagnose the battery would cost £140 and to diagnose the camera would cost cost £86 and would cost £140 per hour after that. So I decieded to have another go and noticed that when a door was open the dash would show door open then flash up battery warning sign, but if the boot was open it only showed boot open no battery fault which it then hit me the wiring loom from the boot to the boot lid which I removed and discovered yes 4 wires nearly broken and shorted to gether and 1 completey broken which was causing the battery monitering signal to be shorted out to ecu making it think battery was faulty uping the the output from the alternator to 14.4v as it thought the battery was flat. Anyway all wires repaired and now all faults have now gone but I have ordered a new loom for £86 which I will change when it arrives. So Jaguar dealer If you get this fault and can not figure it out give me a ring and strangley I will only charge you £140 hour because the dealer would have never found this. Thanks Nick with a big smile of satisfaction for figuring this out and saving myself hundreds on pounds.

 

Hi / thanks for posting back and I hope you fixed it. But I'm not convinced. The alternator usually puts out about 14.4v when running all the time. Don't think the battery condition monitor makes any difference to that. And the battery is connected to that circuit. So if the alternator is putting out 14.4 and your battery is only charging to the 12.2 range then I still think you may have a battery issue. So I'd suggest you keep a close watch on it

 

Good bit of detective work - sounds very promising.