As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FOUND MAINT CAUTION LIGHT ILLUMINATED DURING PRE-FLIGHT. GROUNDED - YES. FOUND FAULT FOR LEFT EXHAUST ACTUATOR. REMOVED AND REPLACED LEFT RAM AIR EXHAUST ACTUATOR PER B737-9 AMM 21-51-27/401, OPS NORMAL. NO FAULTS FOUND. GROUND VERIFICATION SUCCESSFUL.