Sleep Mode
To lower the constant battery draw when the vehicle is parked, the complete ZKE system
will go into the “Sleep Mode” 16 minutes after the ignition has been switched off and no
further ZKE function is active.
For example, the approximate E39 (528i) Battery draw is:
• Ignition switch off = approx 750 mA.
• One minute after = approx. 560 mA.
• After 16 minutes (sleep mode) = approx. 18 mA.
All modules in the ZKE system will go into the sleep mode. The P-Bus remains active, how-
ever no data transfer takes place until a wake-up request is received. The general module,
door modules or keyless remote module can wake the system up and put the ZKE back
on line. The K-Bus is active (high) in the sleep mode.
Sleep Mode Criteria:
KL R, KL 15 OFF and no further function activated for 16 minutes.
Wake Up Criteria:
KL R or 15 “ON” or a change in one of the signals listed below.
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Central Body Electronics ZKE III
SIGNAL ACTIVITY ORIGINATING
MODULE
K-BUS High General Module
Door jamb switches (possibility of 4) Low “
Trunk lid lock cylinder microswitch High “
Trunk lid pushbutton microswitch Low “
Interior Trunk lid pushbutton microswitch Low “
Central locking button Low “
Hood microswitch Low “
Trunk Lid microswitch Low “
Interior light switch Low “
FIS sensor Low “
Tilt Alarm sensor Low “
FBZV operational signal High FBZV Module
Driver’s door lock microswitch - (lock) High PM-FT/SB
“ “ “ “ - (unlock) High “
Passenger door lock microswitch - (lock) High PM-BT
“ “ “ “ - (unlock) High “
