I ran a scan on my 2014 XKR this morning with my new Foxwell NT710 scanner. Upon completion (3-4 minutes) my battery has been dead. Was thinking I should have had the engine running, but I’ve never been required to do that before on other cars. So I charged the battery to 13.3V. Still won’t start. And the voltage in the battery goes quickly to below 12.6V.

The battery was replaced last year with factory OEM unit. Has shown no symptoms of a failing battery up to now. Below is a quick video of the battery when I have the battery attached to a 1500A battery booster. If you turn the volume up, you can hear a relay clicking.

Any ideas?

https://share.icloud.com/photos/05c5...wJ519kme_Jyu4A

 

You can run a scan with the ignition on or the engine running. It depends upon what you are trying to read.
If the battery is connected to the car, there could be a drain so you should disconnect the +ve battery terminal and then fully charge the battery and then measure the voltage at least 6 hours later. If it is still below 12.6V then the battery needs replacing. If it is still above 12.6V then there appears to be a drain. I'd be surprised if this is related to the Foxwell but it is possible.

Richard

 

3-4 mins... ITBS.

 

Thanks Richard. I did not disconnect the battery when I charged it. But it went from 12.3 to 13.3V in about 2 hours. When I tried to start the car, it was essentially dead. Just a few relay clicks. And after a few tries, it was down to 12.4.

I’ll disconnect the battery tho and try again.

Do you know the reset method? I thought it was touching the + and - cables. Does that sound right?

 

The reset does nothing for a battery that has lived its life. It strictly deletes the volatile memory (and non persisted codes) maintained in some modules.
Your 13.x voltage reading is irrelevant. What you are reading tis the residual charging voltage. As @RichardS suggests, an accurate voltage reading can only be done following 6 hours of rest following a charging event.

Replace the battery and get back on the road.
Cheers.

 

I did not think a reset would revive a dead battery. I don’t think mine is. As I said, the battery is new. It is a Jag factory unit installed at the dealer last year. It has shown no symptoms of failure. I also tried a battery booster this morning, which I used one other time and it worked fine. Not today tho. No starter just relay clicks. But thanks, I’ll leave the car on the charger over night.

Also, the scanner is a Foxwell NT710 and has never worked since I got it. The last issue was the scanner would not complete the system wide scan. Died at 67% everytime. When I reported it, the support group said they found the problem and my scanner needed 2 new files uploaded. This was done last night by Foxwell. Now the system wide scan completes. But I can’t help but think this problem is related to their software change and the update. I doubt it has been tested on an XKR. Dunno tho.

 

What were you doing with the scanner?

 

System wide scan. It ran normally and reported a fault with the fuel evap system.

 

My thoughts, as possibly worthless as they my be: I wonder if, during the scan, the Foxwell "turned on" a module but failed to shut it down when the scan failed. I would, as others have suggested, remove the battery cables, and fully charge the battery. Then, before trying to start the car, I would do the double lock from the key fob, with a window OPEN, just in case; can't hurt. Then try to start the car. My Foxwell NT510 has, on occasion, given me heartburn, usually if I unplug it with the car running.

 

Your comments are far from worthless. Thank you Joe. I probably didn’t explain the timeline well. When the scanner was stalling out at 67%, the car was unaffected. It started fine. It was after Foxwell support uploaded the files to the scanner and the scanner completed the scan, when the battery issues arose.

I am charging the car over night with the battery cables off. But I don’t think it will work because I tried a Jump Starter device that I’ve used before. It works great. But this morning, nothing. Just like starting it after a 2 hour charge. No starter, only a few clicks from relays. Good idea about double clicking before starting. I wouldn’t have thought of it.

I think the scan affected something. Maybe because I did not have the car running?

Frustrating.

 

Frustrating indeed. You should definitely not unplug an OBD device with the engine running or with the ignition on but you definitely do not need the engine running to perform a scan. I perform most of my scans on many vehicles with the ignition on but the car not running but the battery on a charger.
As you suggest, whilst waiting for the battery voltage to stabilise once it is fully charged and you have removed the charger, hold the two disconnected battery cables on the car together for 15 seconds to ensure that all modules are discharged.
Check the battery voltage as soon as you remove the charger as it should be above 13V. Then wait 6 hours and measure again. A fully charged battery should show between 12.6V and 12.9V and a figure below this normally means that the battery is faulty although it's not a totally reliable test as a battery can deliver 12.6V but be unable to deliver it at the correct current. However, it is the right diagnostic starting point.

Richard

 

Thank you again Richard. After leaving the battery alone on the charger over night, to my huge surprise, the car started. Before reconnecting the cables, the voltage read 13.59V. After reconnecting the cables to the battery, the voltage read 12.59V. Quite a drop. Thank you for the guidance on performing the reset. I will do that right now.

I am going to try to watch the Voltage when I run the next scan. I still think it was that process that discharged the battery so dramatically. The car started and ran normally right up to when I ran the first scan. The battery was down to 12.2V upon its completion.

 

The usual advice when doing a scan is to either connect a charger to the battery, which is what I do, or run the engine to keep the battery charged. Some cars seem to drain more juice than others when doing a scan and I suspect that our Jaguars are amongst the worst.

Richard

 

Excellent advice. That was my first thought when the battery died. I should have kept the engine running. Quite a number of folks thought it was unnecessary tho.

Still surprised the battery jumper didn’t start the car tho. I’ve used it before and it went fine. That battery must have been severely discharged in the scanning process. And as you said, that is probably a Jaguar thing. I can scan my other cars without the engine and never a problem.

OK, thanks again Richard.

 

Patience is a virtue.

Should you ever be inclined, take a voltage reading from the cold battery, following a rest of 6 hours. That is the only way to measure the health of a sealed battery. If its below 12.6v, it is on its last days.

Your initial message stated the Reader was connected for 2-3 minutes. There is no way that alone drained the battery.

There are plenty of resources available from authoritative sources (like the Varta website) as opposed the the abundance of noise readily available on the internet concerning battery health.

Cheers

 

Thanks guy. I am pretty sure it was indeed the scanning that drained the battery. I’ve heard from others with these NT series Foxwell scanners and Jags, and evidently scanning without the engine running is problematic . In any case, after leaving the car on the charger over night as per your suggestion (thanks again), the problem is gone. I drove 75 miles yesterday running errands. The car starts normally. I will run a scan again later in the week with the voltmeter attached, to see if there is a sudden drop in voltage.

Do you have experience with Foxwell? I must say, their support team is not very impressive. And given the problems I had just getting the scanner to power up and configured, neither is their product.

 

I know the question is to Guy but others who have had the Foxwell units give it mixed reviews. Some like it, others have issues like you're experiencing. Consider investing in the Autel AP200 on Amazon for around $65. The app fits on your phone. It will read all Jaguar codes, including body, chassis etc. It will record live data and you can do some basic resets such as resetting seats. I have SDD and use it for most things but for basic things lie running a full scan, I use the Autel. It's faster than setting up SDD. For the shade tree mechanic it's an excellent tool.

Like any scanner, you should have battery support while using. My two cents.

 

Foxwell “works” but I learned to not use it while the car is “on a drive”.
As @Sean W suggests, the Autel is better. I use it on the Land Rovers too.

 

Exactly. In fact I just scanned the car and left the engine running. Went fine. But to “Clear Codes”, the scanner says engine must be off but ignition on. I checked the voltmeter the moment I turned off the engine, the voltage drop from 13.5V to 12.5V. So my problem a few days ago probably came from leaving the scanner and ignition on for too long a period of time without the engine. A fragile electrical system….

 

fwiw...my foxwell nt530's guidance is that engine should not be running but ignition on.
..resetting my seats requires the engine to be running.
also, I did a scan some time back and the result was that my sound system no.longer worked.
rescanned. same result, took a break tried again and all went fine.
WJ