ECM - Motronic Control Units Identification
87BMW02GROUP 12 Engine Electrical -
Bulletin Number 12 04 87 (1453) Page 1 of 2
Montvale, NJ August 1987 Technical Dept.
SUBJECT: M1.1 Motronic Control Units
MODELS: 325i, 325iC, 528E from 3/87, 735i (E32)
Situation: With the introduction of the Motronic M1.1, a new generation of control units is used in the following vehicle types: 325i, 325iC, 528E from 3/87, 735i (E32).
The basic control unit is acquired from the manufacturer as unprogrammed hardware. It is encoded by BMW with an individual variant control code (combination of digits and letters) for each version at a special programming station during car assembly.
Explanation: The basic control unit has two information labels (see sketch, items 1 and 2).
Label No. 1 bears the BOSCH number. Label No. 2 bears information for internal factory use. When the control data (software) is programmed into the basic control unit, the adhesive Label No. 3 with BMW logo is affixed to the control unit at the factory, indicating the variant control code (4-figure combination of digits and letters) and the VIN number. The adhesive label may be located either on the side or on top of the control unit.
Identification:
Original Equipment M1.1 Control Unit
Note: On replacement control units there are seven zeros in place of seven VIN digits on Label No. 3.
In case of doubt, you can always double-check if the variant control code and the BMW part number on the vehicle's control unit correspond with the actual parts microfiche. The microfiche usually lists the variant control code on the left side and the part number on the right.