What was found
COCKPIT AIR TEMP GAUGE DOES NOT ACCURATELY REFLECT THE TEMPERATURE SUPPLY DUCT, PAX CABIN, PACK TEMPS ALL READING AT OR BELOW 10 DEG C. F/A REPORTED CABIN TEMP OK OR SLIGHTLY WARM. ACFT GROUNDED. REMOVED & REPLACED THE TEMPERATURE CONTROL MODULE, IAW AMM 21-61-15/401. NO HELP. WHEN SELECTING ZONE TEMP CONTROL KNOBS TO FULL WARM TEMPERATURE DOES NOT CHANGE IN CABIN OR GAUGE. TROUBLESHOOT IAW FIM 21-61 TASK 861. PACK TEMP CONTROL BITE SHOWS NO FAULTS. REMOVED & REPLACED TRIM AIR PRESSURE REGULATING AND SHUTOFF VALVE IAW AMM 21-62-01/401. OPS CHECKED NORMAL. TEMP CONTROL INDICATION CHECKED NORMAL IN ALL POSITIONS.