As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FWD AND AFT TEMP CONTROLS NEED TO BE ON FULL COLD TO GET ACCEPTABLE CABIN TEMP. DUCT AND CABIN TEMP GAUGES APPEAR NORMAL. FLIGHT DECK CONTROLS AND INDICATIONS NORMAL. GROUNDED - YES. PERFORMED PRESENT FAULTS CHECK AND FOUND CODE 21-55011 R/H RAM AIR DOOR ACTUATOR SIGNAL ERROR. PERFORMED B737-9 IFIM 21-51-00-810-804 WITH NO FAULTS FOUND. FAULT NOT ACTIVE.