FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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System Components




System Components

General Module (GM IV): The GM is a microcomputer that is the central component (heart) of the Central Body Electronics. The GM is located behind the glove box.




The main objectives for using the GM are:
- Increase Overall Reliability
- Centralize Electronic Systems
- Decrease Assembly and Service Repairs
- Centralized Diagnosis of all ZKE Components
- Individualization of Features (Coding)

The GM requires input data to perform Central Body Electronics functions. The inputs are supplied by digital switched signals such as:




- Driver's Door Lock Microswitch: supplies voltage (KL 30) to the GM when switched. A path to ground is provided by the GM (internally). The GM monitors the input voltage.
- Central Lock Button (E36 from 96 MY): supplies a ground circuit to the GM when switched. The GM supplies and monitors a reference voltage (5v) that is "pulled" low when the switched ground path is provided.




The GM processes the input information and contains "coded" instructions that allow a specific output control of functions.

The GM will produce output controls using internal transistors to switch relays allowing current flow (providing voltage or ground) through circuits and actuators. Actuators (such as relays and motors) are used by the GM to operate or control various output functions.