Hi. I have a 2014 2.2D XF (X250) which I bought just under 2 years ago. I love the car but there is a problem that is really spoiling my enjoyment. About a month after buying it, the stop start feature stopped working and I started to get the infamous 1 and 3 minute warnings on the info screen. I tried charging the battery to no avail, so booked it into the local dealer (not the one I bought it from). They charged the battery and billed me £140 for the privilege, but at least S/S worked again, for about 3 weeks...

I took to charging the battery myself (in situ) whenever S/S stopped working and when I got the battery warnings. After about a year, a charge was only getting me a couple of days before the warnings came back and S/S hadn’t worked for months. I figured the battery must be on it’s last legs, so bought a replacement from Halfords (95Ah AGM 850 CCA, so same as original). I fully charged it before replacing, but no SS. After a week I tried my voltmeter on the cigar lighter. With car running I get 14.7 V, so alternator is good. As soon as engine is stopped, the bolts will drop quickly from 12.6 to 12.3 unless I fully lock the car, and then I lose signal from the cigar lighter. I see similar behaviour when I use voltmeter directly on the battery. I should add that I replaced battery myself, so wasn’t able to program the BMS that a new one had been fitted.

I suspect I might have parasitic drain, but it’s almost impossible to tell for sure, as the alarm goes off as soon as I disconnect the battery lead to put my ammeter in series. I even pulled the alarm fuse and still it goes off.

I’ve read of similar issues on forums, and have removed USB flash drive, dash cam, etc. I only do short runs (2 x 5 miles a day), so is this possibly my problem?

The car still has extended warranty until May, and is due in for a major service in a couple of weeks at the same dealer who fleeced me last time. Do you think I should ask them to test for parasitic drain, or just advise the SS no longer works?

Any advice would be appreciated. I went back to Halfords and they tested the batter in situ, and said it was fine. For info I charged the original Jag battery that I removed and a week later it was still fully charged, which would further indicate battery is not the root cause of the problem.

 

Instead of disconnecting the battery you can measure the voltage across each fuse - any which is carrying a current will have a tiny voltage (mV) - a fuse is a low value resistor and Ohm's Law applies.

Look closely at the top of fuses - they normally have tiny exposed contacts.

 

Doesn't the 2014 have a separate battery for stop start? Has that been replaced? Most likely that one has failed and is perhaps straining your main battery?

 

Thanks for the replies. I tried using the current draw on the fuses, but many of them have little plastic covers on them that made it a very tedious task and the ones in the footwell are too tricky to get into with a multimeter. The ones I did test I could find any with a discernible draw. It does have the stop start battery which always registers full charge. My understand is that it only has one function which is linked to stop start so shouldn’t really impact anything else.

I spoke at length with the chief tech at the local Jag dealer before the lockdown started. He was very knowledgeable but ultimately it came down to the car could be exhibiting “normal” behaviour or it could be parasitic drain (he called it something else starting with co-). The only way would be to run a test, which if it found nothing wrong would cost me £150. Instead I’m investing in a diagnostic box that will let me reset the BMS, check for fault codes myself, which should help narrow things down a little.

 

For a 5 mile each way drive I wouldn't want the SS to engage... Nothing will be truly up to temperature and the battery is barely recovering from starting the engine.
SS needs more than just voltage to work but BMS calibration won't hurt since that annoying little unit controls so much.
Battery low early signs tend to be things like air vents not opening automatically, heated seats unavailable.
If everything else works fine and no dash battery timer warnings I'd give the battery a good charge ( BMS unit disconnected or charger on the battery post before it) and try a longer drive to get temperatures up.

 

Thanks for the reply. I should clarify, the SS doesn’t function at all now - the 5 mile trip is just my typical drive to work, but it does get used on longer runs too and even then it doesn’t function. Interestingly back in the early days just after I bought it SS would kick in after a run to work and then a run home too (it’s 6.5 miles to be exact and most of it on dual carriageway).

The low battery warnings come with all of the usual accompanying features you mentioned (vents don’t rotate, etc.)

Due to the current Covid issues, its sat on the drive for the last two weeks. I fully charged it and after two weeks of lying idle The battery had dropped to 12.3V and I got the battery low, please start engine warning as well as no vents, etc. but it did start. I had to open the doors and boot (trunk) a few times over the two weeks which probably ate a chunk of charge too.

I’m hoping the BMS reset will help some, but I must say that Jags appear to suffer badly from these battery issues. It’s a bit of a shame, as otherwise it’s an excellent car.

I’ve ordered a Foxwell NT 650 to reset the BMS, check for other faults, etc. I will let you know what I find.

 

That's 12.3v.. Was that after being charged or just before.
When you charge the battery... Do you remove the battery cables?
I get similar issues on my 12' model xfr but its still on its original battery... Warmer weather is definitely helping reduce the No vents etc but oy had 3 or 4 low battery displayed low battery warnings.
The battery you have should still be under warranty so if any Halfords near you is open... Nip round and let them test it.

 

Hi, thanks for the reply. The battery is 12.8 or 12.9V after a full charge. The 12.3V was what it dropped to after sitting unused for 2 weeks (I opened the doors and boot a few times during the two week period, but did not start it at any point). Unfortunately everything I do is with the battery connected to the car- trying to disconnect just sets the alarm off. I have already gone back to Halfords and had them test the battery- it showed good on their tester machine.

In a nutshell I’ve come to the conclusion that I have parasitic drain (quiescent Jaguar call it). I just don’t know if it’s within limits or not.

Since my last post I’ve received my NT650 and reset the BMS so the car now knows it has a new battery. I’ve fully charged it, and will be taking the car out for a run tomorrow, so it will be interesting to see if the SS begins to work again. Unfortunately the BMS reset cleared all fault codes as part of the reset process (I didn’t realise it did this before initialising) and hadn’t thought to check for fault codes before I did the reset.

i will post back how I get on.

 

Well, good news to report. I took the car for a run today and stop start is working again for the first time in many, many months. It looks like the BMS battery reset has done the trick. I also noticed that with the engine running the alternator is now supplying 12.9 V to the battery whereas before the reset it was up at 14V. I’ve read that it’s an intelligent charging system, so presumably it was giving more volts as it still thought I had the old (presumably bad) battery connected, and now it recognised a new battery it has lowered it accordingly.

I’m glad to have resolved my main niggle, and have even removed the voltmeter I had semi-permanently wired onto the battery.

Thanks to all for their helpful suggestions.

 

Curious... Where did you get the Nt650 and why specifically it?

 

I got it from eBay. I toyed with the icarsoft lr 2 but which cost about the same but is limited to Jaguar and Land Rover cars only. The NT650 covers most manufacturers and models and gets a good write up for about same cost. I have the added bonus of being able to use it on other family members cars too.