ecu makes a high pitch sound at light loads?

[gtodave]

In my legnum pfl manual at about 100kmh cruising when you come to a slight
incline and i give it a slight bit of throttle i can hear the ecu emit a high pitch tone,
if i back off and then accelerate slightly the tone changes up and down.If you have the radio on you can't hear it,my misses can't hear it .
i checked her galant and it does the same but much lower volume.
has anyone else heard this?
thanks david

 

[bradc]

Are you sure it isn't your turbos?

 

[ygoslo]

Yeah what Brad said, I can't imagine the ECU making a noise like that. Can you think of anything else it could be?

 

[OVR444]

I was thinking alternator whine....

 

[godzilla]

Yep, what they said for sure. That or a interference through the speakers. Mine does it. Ever since I had the new stereo installed, it will do it so slightly. When you have the stereo up, you cannot hear it - only when the volume ishtar can you hear it.

 

[naughtika]

what I've noticed is.. JVC headunit does it.. but with Alpine.. never.. so there must be some sort of attenuator built in the Alpine's system?!