As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW NOTED BURNING ODOR IN COCKPIT DURING TAXI. PERFORMED GVI OF FORWARD AVIONICS AND UNDER FLOOR COMPARTMENTS. PERFORMED OPERATIONAL CHECKS OF WINDSHIELD HEAT, ANTI-ICE, AIR CONDITIONING AND ENGINES WITH NO DESCREPANCIES NOTED. AC RETURNED TO SERVICE. (SW21200404961)