What was found
DURING TAXI AFTER FLT, LOST CONTROL OF CABIN TEMP WITH APU BLEED AIR ON. CABIN TEMP CONTROLLER WOULD NOT CONTROL VALVE IN AUTO OR MANUAL MODES. PRODUCED SMOKE FROM CABIN FLOOD VENT. SHUTDOWN APU. SMOKE CEASED. NO PROBLEMS DURING FLIGHT. CABIN TEMP OPERATES NORMALLY WITH ENGINE BLEEDS. REPLACED COOLING TURBINE, HOSE, AND SEAL IAW THE MM 21-10-87-201. PERFORMED OPS & LEAK CHECK IAW MM 21-10-15, 201 AND 21-60-00, 501. NO DEFECTS NOTED.