Oh my new to me ‘15 XKR, I assume it has sleep mode. But, I can’t find any details on how it works. Hopefully someone can help.

- What exactly does it do?
- How is it activated?
- How do you know if your car is in sleep mode?
- What causes it to exit sleep mode?

 

The car goes into sleep mode when it is locked and the modules shut down (typically 5 minutes or so). If the car is not locked then it can take up to a half hour before all modules shut down and the car goes into sleep mode.
The driver is not involved in any of this. It is purely a question of whether the car has been locked or not.

 

This should answer your questions:

In the unlocked state, the vehicle will take 30mins to shut down to its min quiescent current.

Locked as follows -

• Select ignition mode (without starting the engine) for around 10 seconds. Shut off all accessories -

• Deselect ignition mode, close doors, hood & luggage compartment lid latch.

• Lock vehicle.

• After 15 minutes on vehicles with TPMS installed or 4 minutes on vehicles without TPMS installed

 

What it does is place your car in a standby security state. It's never fully off. Security is running and it seeks the fob. Basically you are placing the vehicle in a minimal quiescent drain state of 35 ma.

Any action that is opposite of the above takes it out of sleep mode.

 

See quiescent current draw in answer to you other post:
15 XKR having random start issue - Jaguar Forums - Jaguar Enthusiasts Forum

 

Superlock mode puts the car to sleep instantly, double press the lock button on the key fob.

 

Sorry..but I was an engineer and I need details.

Does anyone know specifically what shuts down during sleep mode?

 

@XKDreams , you speak my language.
@CA Jag , this may be helpful for you.
The electrical guide speaks to the power distribution from the battery to the Power Distribution Box, the Central Junction Box and the Auxiliary Junction Box. It is a good read.
And as long as the Central Junction Box and Auxiliary Junction Box receives power... Of course, the inquisitive of us like to refer frequently to XK2008ConnectorQuickReferenceGuide. (Tried to upload it but I keep getting errors)

It true that as long as you are “not” fitted with TPMS, locking the vehicle “may” shut down all systems within 3 mins. (just don’t open the boot, doors or bonnet, touch the controls or even the door handle)
But if the vehicle is fitted with TPMS, the vehicle “will” take 30 mins to shutdown (as above, don’t touch anything)... coincidentally, the very same amount of time by not locking the vehicle.

If a 30mA drain is troubling for your car for a month or two…. that is the car’s way of saying “please get me a new battery”.

All I can add is my experience in these matters. It seems I do not have the privilege of dealing with the depleted battery situation as often as some others. And that suits me just fine.

Cheers!