Hi guys just on here to help my dad out. He has a 2014 jaguar XF 3.0 supercharged all-wheel-drive very low-key 60,000 KM he was on the highway and as he pulled up to a light, the car all of a sudden stalled the dashboard lights went crazy And he couldn’t get it out of gear or start. Had the car towed to the shop once they had a chance to look at it, they said need to replace the battery and alternator had the alternator and battery replaced. My dad picked up the car from the shop as he drove it home. He noticed a light that said battery not Charging Spoke to the shop. They said not to worry after a little bit of driving it will be fine. He drove it home. He did not drive it for much longer woke up the next day started the car started. No problem took it out on the highway driving along 2025 minutes While coming to a full stop the car stalled and the dash lights were flashing all the symbols and he no longer can start it or put it into neutral to push it. Anyone have any idea as he has lost faith in the mechanic shop. Maybe faulty new alternator or could it be a electrical issue…

 

on these cars the battery has to be programmed into the system , but also on the negative terminal the small bcm can go bad ,inexpensive part to replace

 

much appreciated .. shop is saying be alternator they put in was faulty… so they are putting another one. Could it be because the battery wasn’t programmed so the alternator didn’t know to charge it ? When we got it back with a new battery and new alternator the dash said battery not charging? What happens if the battery wasn’t programmed?

 

The Service Manual says that the Battery Monitoring System(BMS) should be recalibrated when a new battery is installed. The software in the BMS then calls for the alternator to charge the new battery until it is fully charged. When the BMS monitors the battery and finds it fully charged it signals the alternator to begin reducing the charge rate until the battery is about 75% of full charge. It does this slowly over a period of time and never lets the battery level fall below 12.2v. The BMS then calls for the alternator to charge the battery to fully charged.

It actually is not necessary to recalibrate the BMS because it is already programmed to behave as described above during normal operation of the vehicle. The recalibration just causes the BMS to start the process immediately after the new battery is installed

I installed a new fully charged battery in my 2012 XF about 4 weeks ago and because I have SDD I recalibrated the BMS. It has taken almost 3 weeks(about 200kms of local driving) for the BMS to reduce the battery to 75% of full charge. I monitored the charge rate of the alternator and it was typically 11.9v -12.3v. Now it is charging the battery at 13,0-13.4v.

During the battery change I powered the car through the diagnostic connector and I had no issues with any of the car systems.

 

Hope the replacement alternator does the trick!
We have had several reports of this. One suggestion is to NOT replace the OEM alternator but to get it rebuilt by a local shop. Also check the cam covers for leaking oil down onto the alternator. I did not think that would cause a failure but I was wrong and again we have had people report that it did cause an alternator failure.
The BMS is not the problem.
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Thanks everyone .. great info.. the other question is the battery would have just been drained till it died again on the hwy… is it true that the battery is now lost life span due to not being 100% drained since new. They replaced the alternator today so I guess the first one was faulty. Unlucky I guess. They are keeping her overnight and driving it to make sure… my dad is worried the batter is compromised now .. the shop who I trust says it’s not an issue ? Thoughts ?

 

What is the resting battery voltage after the car has sat all night? This will tell you a lot. I keep a voltage monitor plugged into the cigarette lighter that's in the console on my XJ. That way I can look at the battery voltage at anytime. These are all over and about $10 or so and they usually give you a USB charging port as well. Not sure about the XF?

Yes those kind of incidents do affect the battery for sure but how much is always the question. If only that one time I would run what you got.
Now you should consider keeping the car on a battery maintainer. The preferred one for Jags is the CTEK one. Many threads on peoples install in various Jaguars.
Just don't get the Jaguar branded one unless you just want the Jaguar logo. It's the same charger with or without the logo. And man does that logo cost!

With how few miles he puts on the car per year I think it would be mandatory to keep it plugged in when not in use.
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