Dig up this thread for the purpose of sharing my experience with my iDrive. A few days ago, after completing a long journey and sent my friend home, few seconds after he alighted from my car and slam shut my rear right door, the iDrive just black out. Doesn't respond to reset method or the big round idrive button. Quickly stopped my car by the road side and switch off the engine and then on again but to no avail. Luckily the driving function and air cond are not affected, just that you can't listen to audio and can't access the iDrive menu. Went home and quickly lock down the car and frantically searched the net for causes and answers for about 1 1/2 hours. Found out that our iDrive is regulated by a module called Micro Power Module (MPM) which is located beneath our spare tyre at the trunk. There are two modules here, one white (the MPM) and the other black (thats for the PDC). Went to have a look at the said module and was relieved that it was not submerged in water which may have leaked into the area (as experienced by some). I have uploaded pics of the MPM here.
After dinner and some prayer :biggrin:, unlock the car and insert the key and bingo, the iDrive screen came on again as usual. No lag and no delay in starting up. Thereafter, for the past 2 days, have been driving her around town and the gremlin has not shown up again. Keeping my finger crossed. Phew.
Some of the excerpts i have extracted from the function of the MPM are as follows:-
"How it works
The micro-power module (MPM) enables consumers to be switched off in a defined manner if a fault develops while the vehicle is out of use. The MPM is linked with other control units in the vehicle to allow it to transmit and receive CAN messages via the K-CAN. The MPM has a bistable relay which controls terminal 30g-f. If the MPM detects a fault, the relay will switch terminal 30g-f off. The reason for the deactivation will be stored in the MPM.
The following consumers are connected to terminal 30g-f:
- Multi-audio system controller (M-ASK)
- Car Communication Computer (CCC)
- CD changer (CDC)
- Japan navigation system (JNAV), Korea navigation system (KNAV)
Conditions required for switch-on
The switch-on conditions for the bistable relay are:
- Battery connected
- Vehicle unlocked
- Change in condition of door contacts or boot-lid switch
The MPM is woken up by activity in the K-CAN. After being "woken up", the bistable relay returns to the switch state it was in before it was "woken up".
Conditions required for switch-off:
The switch-off conditions for the bistable relay are:
- Off-load current too high (more than 80 milliampères) and battery's starting limit reached
- Undervoltage
- Permissible number of "wake-up" actions in K-CAN exceeded
- Bus active after 60 minutes with terminal R OFF without any switch-on conditions being satisfied.
The time is reset by switch-on conditions, e.g. by a door being opened. This means: The vehicle is unable to go into sleep mode after terminal R is switched OFF. There is no limit to the number of times this process can be repeated. It could thus cause the battery to become discharged!
The MPM goes into sleep mode approx. 1 second after the K-CAN goes into sleep mode. Before the MPM goes into sleep mode, the current switch state of the bistable relay is stored.i
SBT"
So from the reading above, could have been caused by one of the things which may caused the MPM to switch off as " Off-load current too high (more than 80 milliampères) and battery's starting limit reached
- Undervoltage
- Permissible number of "wake-up" actions in K-CAN exceeded
- Bus active after 60 minutes with terminal R OFF without any switch-on conditions being satisfied." :stupid:
Even the opening of a door can reset the time for the switch on condition for the MPM.