Engine Sensors & Switches: Notes

NOTE: Due to a production change, Cabriolet and 90 models are equipped with one of 2 different ECMs. Early version ECM can be identified by part number 4AO 906 266 A/AA/AB (MMS 200), referred to as ECM "A" in this article. Later version ECM can be identified by part number 8AO 906 266 B (MMS 300), referred to as ECM "B" in this article. 100 models use ECM "A".