auto shutdown of convenience systems

[bigb]

I have recently been told that my Q7 sufferred a "low energy" signal and consequently the car then begins a progressive shutdown of convenience systems. The logic i guess is to recover energy.

By convenience systems - i understand these to be:
- auto recirculation
- sun roof
- some aspects of the dynamic suspension
etc etc.

Does anyone know a bit more about this?
Specifically:
1. What systems exactly can be shutdown?
2. What order would these be shutdown?
3. Once the cars energy levels are back up why are these system not automatically re-activated?
4. Why is the user not notified that the car has shutdown some systems?

While this sounds like a logical approach to a low power problem, I am just a bit sceptical about all the details, and in particular not pleased that the user is not notified of this. I had to find out when i complained that the auto recirculate was not operating and that the suspension seemed to have become "rougher"

Any pointers on this would be greatly appreciated!
2006 Q7 4.2 FSI

[a8 tech]

You can code the battery display onto the mmi screen to show battery status,any way heres some info.Battery management has a set criterior and load stages are alerted when the battery is discharging turning certain functions off,not just convience but also it can put the most network to sleep amongst other networks,The energy management control unit J644 is
responsible for constant monitoring of the
battery, which includes checking the state of
charge (SOC) and starting capability. The
control unit regulates the optimum alternator
charging voltage with the engine running. It
can implement load shedding (reduce the
number of loads) and increase idling speed.
To reduce the closed-circuit current with the
engine OFF, the energy management control
unit can deactivate loads via the CAN in
extreme circumstances and thus prevent
excessive battery discharge.There are 6 stages of battery shut off.The individual deactivation stages are
initiated by the energy management control
unit in line with the charge of the vehicle
battery.
The deactivation stages result in the
following:
Deactivation stage 1
Convenience CAN loads are deactivated.
Deactivation stage 2
Initiation of this stage results in
deactivation of additional convenience
CAN loads. Certain infotainment system
restrictions are implemented.
Deactivation stage 3
Reduction of the closed-circuit current is
initiated.
Deactivation stage 4 – Transportation
mode
This deactivation stage is activated by way
of the diagnosis unit and cannot be
initiated independently by the energy
management control unit. Deactivation stage 5
The auxiliary heater is deactivated.
Deactivation stage 6
Bus system wake-up action is reduced.Sysyems involved are(depending on the spec)The following systems are involved in load
deactivation by way of the closed-circuit
manager module in the energy management
control unit:
– MOST bus
Front information display and operating
unit control unit J523
CD ROM drive R92
CD changer R41
TV tuner R78
Digital radio R147
Radio module R
Navigation system control unit J401
Digital sound package control unit J525
Telephone/telematics control unit J526
Aerials
Chip card reader control unit J676
The loads/functions deactivated are indicated
in the assisted fault-finding routine under
"Vehicle information" as part of the "Function
and component selection" section.AlsoConvenience CAN
Sunroof electronics control unit J528
Seat adjustment with memory control unit
J136
Seat adjustment with memory control unit,
front passenger J521
Seat adjustment with memory control unit,
rear J522
Climatronic control unit J255
Additional heater control unit J364
Convenience system central control unit
J393
Onboard power supply control unit J519
Onboard power supply control unit 2 J520
Door control unit J386
Door control unit J387
Door control unit J388
Door control unit J389
Entry and start authorisation control unit
J518
Tyre pressure monitor control unit J502
Control unit with display in
dash panel insert J285
Driver identification control unit J589

[Sportingmac]

Missed the bit about coding the MMI to show battery status - where can I find that info please A8?

Thanks

[a8 tech]

goto address 07
then goto adaptions (10) channel 2 and add 32 to the value
reset the mmi and check the car menu