Positive and Ground Supply

Positive And Ground Supply And Diagnostic Link

Positive supply
The voltage supply of the engine control module is structured as follows:

Terminal 15 ON is signaled to the control module directly via a separate pin.

Consequently, the control module activates the main relay. The main relay supplies voltage to other inputs of the control module. In the same way, the main relay secures the voltage supply of other control modules and components.

The engine control module still requires a permanent voltage supply via terminal 30 for memory purposes.

Ground supply
The ground supply of the engine control module is ensured by several pins which are, however, interconnected internally.

Diagnostic link
The engine control module can be addressed with the tester via the diagnostic link. Terminal 15 is generally required for diagnostic purposes.