ECM What's its function? Is it to give power to the distributor?

the ECM / Computer controls spark timing, fuel delivery and emission controls. Continuously receives signals from sensors and input devices on or near the engine; sends control signals to valves, controllers and other output devices. Stores "trouble codes" and warns driver when service is needed. Vipes

ECM is mainly for fuel and ICM is for Ignition on Bosch LH systems. They are linked in their actions and share a few common sensors (except for Motronic systems which have only an EMCU, or Engine Management Control Unit). All the best, Peter. :car-smiley-031:

how Do I test to see if my ecm is still functional ? 89 740 turbo