1997 Civic EX, manual, 147k miles. My ABS light started coming on when my RPMs exceed 2500. It will go off once it goes lower. It's not generating any codes. I've read the ABS module is sensitive to voltage - could this be an alternator issue at high RPM? Battery is fine, drives fine otherwise so far.

 

Any update?

 

It was the alternator. I checked the battery voltage at idle (13.6-14.4v) and at high RPM (17v). No problem since having it replaced. Hopefully, it didn't damage anything too badly while an issue beyond a headlight that went out.