Is it common for the ecm to make a buzzing noise? It is hardly detectable unless you are right next to it. Has anyone experienced this, thanks for the help.

I've never noticed mine buzz. It may be a sign of something trying to short. Does everything still work properly? What year (is the ECM in the dash or the engine compartment)?

does it have a good ground? i know if mine doesnt have a ground it clicks and makes noise.

The year is 1992 and the ECM is under the dash. The old one was acting funny, no start, die going down the road. It would have spark, fuel, and injector pulse, but would not fire. The old ECM made this buzzing noise also but I didn't notice it until i went to change it, who knows how long it had been doing it. With the new used one the car runs fine, but still has the buzzing noise. I have checked several of the grounds are there any a person would recomend. Thank for the help!

I'd bet it'* one of the adjacent relays in the relay center at the base of the A-pillar. They're right next to the PCM. With the ignition on, but car not running, try pulling fuses one at a time until the noise stops. Figure out what circuit it is.