As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ON TAXI OUT, FLT CREW OBSERVED A MISMATCH BETWEEN THE LT AND RT INBD AILERONS. OBSERVED FROM THE AILERON INDICATION ON SECONDARY EICAS. NO MESSAGES GENERATED, VISUAL INSPECTION ACCOMPLISHED FOR FULL AILERON TRAVEL IN BOTH DIRECTIONS. NO BINDING EVIDENT IN CONTROL COLUMN. AILERON POSITION INDICATION DEFERRAL APPLIED.