Working on '89 GTA w/1227165. I cannot figure out why I do not have 5volts coming from the ECM on the B12/MAF signal terminal when disconnected. I even got some ECM pigtails from the yard and setup a bench test to prevent the possibility that something on the car is draining the power from ECM and ckt 998 (MAF 5v Signal) or even the possibility of a short. I had a couple of guys probe their MAF signal on B12 and they were getting 5.2v and 5.7 volts. The FSM states the minimum is 4volts and if it does not have 5v then the ECM is faulty or the MAF signal circuit (B12) is shorted. I have been through 5 ECMs and they all spec out the same. I simply cannot move on with this car until I absolutely for certain know why my MAF signal is so low, 3.7v I put this here because I know you guys are intimately knowledgeable of the ECMs and how they operate. Thanks for any input, been through hell with this issue.
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