Emission Optimized - Ignition Key Off: Notes

"Emission Optimized Ignition Key Off" is a programmed feature of the MS 43 DME. After the DME detects the key being switched OFF, the ignition stays active (main relay/voltage supply) for two more individual coil firings. This means that just two cylinders are fired - not two revolutions.

This feature allows residual fuel, injected into the cylinders as the ignition key is switched off, to be burned as the engine runs down.

The unloader relay, previously used in the MS 42.0 system for ignition coil KL 15 supply, is now supplying voltage to the injection valves. The ignition coils' KL15 voltage is provided by the DME main relay.

When KL 15 is switched off, the DME operating voltage is removed. The DME will maintain a ground to the main relay for a few seconds to maintain ignition coil supply voltage.