Jaguar XE not starting.

[ericmark]

When it failed to start, there is no sound of it even trying to crank engine, just clicking in the boot, turning off lights, wait retry and it started as if there was never anything wrong.

So just in case put a Smart charger on battery, maximum charge rate 3.8 amp it dropped to 3A rate and then 0.8A rate but even after a week it had not dropped to the 0.1A charge rate battery showing 13.6 volts when finally taken off charge before next trip.

Even then would not start with lights on, used for 3 days lot of miles covered, and then refused to start even with lights off, turned of heater fan, retried and it started so not turned off until home and where I could re-connect the smart charger. The volts shown before switching on charger were 12.4 volt which seems rather low for a battery minutes after turning off engine.

So looking at a number of possible faults.
1) Battery.
2) Car having some thing left on.
3) Alternator not charging.
4) Engine management not permitting it to start.
I am thinking engine management most likely, it has never worked the stop / start thing, and some thing seems to stop the starter motor even trying. To run for 3 days without charging a battery when it still had a problem on first start, does not point to not charging at all, yet 12.4 volt straight after Parking seems too low for a battery just off charge.

Any ideas?

 

[alan333]

To check if something is draining power - take off a battery lead and skiff it against the battery post again. If it gives a spark there's something using power.
The alternator should throw somewhere between 13.5 - 14.5v with engine running.

In my car, the engine stop/start won't work if the battery isn't fully charged.
My money's on the battery.

 

[Burnerman]

I’d agree with Alan......how old is the battery?
Not sure about the clicking in the boot though.....is there a solenoid in that area?
John

 

[ericmark]

Car registered 2016, so less than 3 years old, I will try to find out hold on ammeter, not down to me to repair, just wondering what the problem is. Do not want to disconnect battery as don't know what may fail if I do. Since battery at 13.6 volt when I took it off charge first time, I would suspect battery as charged as it can be, has to hit 14.4 volts to drop to final stage and may be engine management will not allow it to rise that high? There may be a zenor in circuit to stop over voltage.

 

[ericmark]

This morning voltage up to 13.8 still not dropped into final stage.

 

[Burnerman]

That voltage sounds ideal - I guess theres something else interfering here but Ive no idea what.....Jags are somewhat out of my league!
John

 

[ericmark]

If the battery was not connected to the car, the voltage would progress in stages, 12.8 volt it drops to from 3.8A to 3A then at 14.1 volt it drops to 0.8A then finally at 14.4 volt it drops to 0.1A if the voltage continues to rise second time it hits 14.4 volt it switches off, if however the voltage drops to 12.8 volt it returns to 0.8 amp charge rate.

So left on charge normally all stage lights will light and the battery will sit just over 12.8 volt, it will rise to 14.4 volt every so often, but most times when one looks it will sit at 12.8 volt.

However 0.8A is not much, and any drain on the battery will cause it not to reach final stage, however the battery should be fully charged unless faulty.

So question is why did the car not start when just taken off charge, then run for 3 days with battery voltage dropping to 12.4 volt, it should have either remained high if car was charging, or the car should have stopped starting well before that, which is what makes me think the problem lies with engine management.

 

[Belle427]

I can't help much but these modern smart variable charging systems can throw some strange faults with battery problems.

 

[empip]

Any use ?
https://www.xeforums.co.uk/viewtopic.php?f=11&t=7237

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[ericmark]

Any use ?
https://www.xeforums.co.uk/viewtopic.php?f=11&t=7237

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Thanks, yes a lot of use, the fault may be simply having the keys too close.

 

[ericmark]

Well Tuesday 5th February 2019 at 3 pm went into Jaguar agents up to that point it had been on charge with smart charger, Wednesday came to collect and they said first thing they needed to do was fully charge battery and it was still not fully charged so they could do tests, so left in Jaguar, Thursday they said nothing wrong with battery, we pointed out it had failed to start on 4 separate occasions, each time less than an hour since engine stopped or being taken off charge, and each time switching off running lights or heater had resulted in it starting, and when it cranked over no sign of battery being discharged.

So they confirmed nothing also wrong with engine management, and they kept car telling us they would ring us on Friday once they had found fault, on Friday they did not phone, I phoned them 4:45 pm and no answer clearly they had gone home. Saturday we phoned, they say car is ready, but still not said what is wrong with it. One would hope if there is an alternator fault that would be quickly detected. There are no warning lights or reports when it fails to start.

The report says if a battery is low, then it will show "Low Battery - Please start your engine" for 3 minutes, then the systems start to be closed down, if the key fob was too close this could have happened, but only thing it said on dash was "Press OK to clear" and since on one time it was taken off charge seconds before trying to start, and as said battery is A1, this should not have happened.

 

[Burnerman]

Another 'fob off' story unless I am very much mistaken......I wonder if they did a battery test when the car was cranking?
Either way, I'd expect the fault to return
Your smart charger should keep the battery in tip top condition, but even those can't detect if a cell is failing under heavy load.
John

 

[ericmark]

They did start to back peddle a little when my wife let slip I was an auto electrician, she did not say I left that behind in 1998 and I worked on commercial not cars.

I am reasonably sure a software problem, however I have to admit a simple loose connection could cause the same problem.

However under warranty, so not up to me to work out what the problem is. I know when I was fault finding at my work, first thing was plug in the laptop, and in the main it would highlight fault, however on many of the machines I had written the PLC program to start with. However be it a car or a machine for making concrete blocks, one needs the software to read what has happened, so however much I would like to DIY, I know I really have no option, I have to let some one else fix my car.

 

[ericmark]

Finally they have decided it was the rear battery, and stop start now works, so seems likely correct.

 

[empip]

I bet this is Eric's son - Why ? Among other small clues... No mention of the Falklands!

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