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Home >> BMW >> 2000 >> M5 >> Repair and Diagnosis >> Electrical >> Body Electrical >> Central Body Electronics (ZKE III) - Overview - E38, E39 & E53 >> Central Body Electronics (ZKE III) >> Seat/Mirror/Steering Column Memory >> Driver's Seat (E38/E39) >> Ripple Count Recognition

Ripple Count Recognition

When the seat is installed and the battery is connected, the ripple counter uses the initial position of the motors as the "Zero Position". Any movement from this point is counted as "+" or"-" pulses as the motors move in either direction.

The pulse position of the motors is stored in the seat module, in an EEPROM (of the PM-SM), before the ZKE goes into its "Sleep Mode".

Fig 1: Identifying Ripple Count Recognition
G03398880Courtesy of BMW OF NORTH AMERICA, INC.

This prevents the position recognition from being lost. If the battery is disconnected before the 16 minute sleep mode activation, the memory positions of the seat will be lost and reprogramming will be required.