Any idea how to activate the touchscreen....does not come on at all.

 

Either push the "ON" button, or maybe your battery needs help. OR, maybe your TSD is deader'n dead.

 

I have it on a battery minder overnight. See what the morning brings. Does low battery also give the Tire pressure alert failure as well?

 

After I didn't drive my car for a week about 2 weeks ago, when I went out to start it, it started right up but no screen, just black. Restarted the car several times with same results. Not only did the touchscreen not work but none of the controls below it on the vertical console. So, I couldn't turn off the A/C, or change temperature, or turn off the radio or change the volume. Drove the car home for about an hour and still no change. Restarted the car and screen was still black. Then I decided to lock the car and then reopen and then restart the car, and everything has been back to normal ever since. It was definitely a battery issue, but it also needed the "reset" instigated by locking the door. Try it.

 

Be aware; I battery minder, tender, maintainer, trickle-charger..... those are NOT battery CHARGERS. They are only meant to do a very slow Top-Off of a nearly full battery. A CHARGE requires 10 amps or more. Even at 10 amps, it could still take 12-24 hours to FULLY charge a battery. NEW batteries have never had a "Full" charge, and inevitably lose power while sitting on the shelf for who-knows-how-long.
75% of the electrical gremlins with these cars is because of Low Battery.
ALSO, sometimes a Hard Reset fixes the weirdest things;
Hard Reset = remove the positive battery from the battery and touch the clamp to the negative cable. This discharges all the volatile memory in most of the modules. DO NOT touch anything to both battery posts, or battery cables while still connected to the battery!

 

Perfect....absolutely solved the screen problem. I really appreciate your wisdom. Thanks

 

Out of interest how long after locking it did you reopen it? I haven't had any battery problems on my '10 XKR but in the early days on my '07 XKR I had to wait for it to drop out of convenience mode before the screen would come back to normal.

 

I didn't wait at all. I sat in the driver's seat, locked the doors with the key fob, opened the locks with the fob, and then started the car. Presto! Screen came right back on and haven't had an issue since as I drive the car a lot each day and battery is now charged.

 

which solved it, the lock of the doors and then restart or the hard reset described by disconnecting the battery?

 

Yes, indeed it does, or rather, can. Low battery voltage can and does give any number of random symptoms including the two you have mentioned. You may be due for a new battery - if so, please note that new batteries are almost never fully charged and often never get fully charged! Make sure it is brought to full charge before installation.