tr 1981 Volvo 240 Lambda Sound control ECU Up for sale is a Working, in excellent condition 1981 Volvo 240 ( 242 / 244 / 245 ) ECU. Bosch Part number-- 0280800033 This unit offers a 30 day functionality warranty. This should fit many early volvo models, & as always with this type of component your best bet is to match the part number to the one on your original ECU. A faulty lambda sound ECU can be a real problem with these cars. Basically this ECU is the oxygen sensor control system that powers the auxiliary fuel injector (also known as the frequency valve) and adjusts the cars fuel curve based on readings from the o2 sensor. These are generally fairly reliable units but can easily be damaged by wiring faults or voltage spikes (caused by a bad alternator). The car will usually still run with a bad ECU, but it can also cause issues with erroneous check engine lights as well as emission control & cold or hot start problems. Also stalling and poor power. If your car does not have these issues but you intend to keep it a while, I recommend our customers keep an extra ECU in the trunk. These units now have to be special ordered from most dealers new for big $$ (often times over $1000!), and you can never find one when you need one. Even now finding a good one second hand is getting to be quite difficult as these cars get older.