BMW Coupes and Sedans 1970-1988 Repair Guide



The engine should be turned off or the battery cable disconnected when ignition system components are replaced or engine test equipment is connected to the ignition system, because of a dangerous current that can be present in the primary and secondary circuits. Personal injury could occur.

All 528i, 633CSi, 733i and 1980 and later 320i models are equipped with a Bosch® transistorized ignition system. The 528e and all 1982 and later models are all equipped with a Digital Motor Electronics (DME) engine control system. DME is basically an onboard computer. It is a microprocessor that controls many more engine related functions than would a conventional system.