BMW ECU Up for sale is a Working, in excellent condition BMW ECU. Bosch Part number 0 261 200 150 . This ECU should work with BMW cars equipped with the 3.5 liter engine including: BMW 635CSi 88-89 Elec Cont Unit (ECU); AT BMW 735i 88-92 Elec Cont Unit (ECU) This is one of the most common no start or random stalling problems with these Motronic ECU's. If yours does not have this problem, keep an extra ECU in the trunk, you might some day be glad you did... These units now have to be special ordered from most dealers new for big $$ (often times over $1000!), and finding a good one second hand is getting to be a very hard chore.