My 2006 RR HSE with 133K miles recently began making a high pitched screeching sound upon starting the engine. Happens on cold and warm engine starts. Sound / noise lasts anywhere from 2-5 seconds then disappears. Sounds electronic (as opposed to mechanical) and sounds like it’s coming from inside the cabin (as opposed to the engine bay). Sound doesn’t correspond to acceleration or RPMs. Don’t think it’s radio related either. No warning lights or error messages. Vehicle runs great otherwise. Has anyone experienced this type of sound or have any thoughts as to what’s going on? Any help would be appreciated…
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Ever figure out what's wrong and manage to fix it? Exact same thing happens with mine now

 

No such luck. Still dealing with the sound occasionally. I now have 175k miles but I hasn’t gotten worse. Still intermittent and more prone upon (just after) colder weather starts. Fades off pretty quickly and doesn’t seem to affect any other functions. If you figure anything out please let me know. Good luck!

 

Are you sure its not something in the serpentine belt??

 

Yes, I’m sure. Belt was replaced for general age during the time this has been happening and it didn’t eliminate the gremlin. As best I can glean, it stems from a component referred to as the ‘ECU box’ whatever the heck that is / does.