Central electronic module

The central electronic module (4/56) is the main control module for central locking functionality. The central electronic module determines how the lock should be locked and unlocked by receiving information on the Controller Area Network (CAN) from other control modules and via the directly connected signal cables from the components.

Signal cables are directly connected to the central electronic module from:

• Lock units in all doors (3/74-77), open / closed
• Lock units in the rear doors (3/76-77), locked / unlocked
• Lock unit tailgate (3/78), open/closed
• SRS (supplemental restraint system) control module (SRS) (4/9), collision/no collision.

The central electronic module is controlled via a direct cable:

• All turn signal lamps, on/off
• Shift relay for power child locks in the rear door, on/off. The shift relay is only installed on those cars equipped with power child locks. The relay shifts between child proof and deadlock positions. The shift between child proof and deadlock occurs by the central electronic module transmitting a signal to the relay, which shifts the relay to the directly connected cable. When the relay has shifted, a control signal is transmitted to the lock motor from the rear electronic module and the lock unit assumes the deadlock or childproof mode depending what the relay shifted to. To ensure that the relay shifts and that the lock unit has time to assume the new status, a control signal is transmitted from the central electronic module for approximately one second.