As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CONT CABIN ZONE TEMP LIGHT ILLUMINATED. GROUNDED - YES. UNABLE TO DUPLICATE DEFECT. BITE OF PACK/ZONE TEMP CONTROLLERS PER B737-900 FIM 21-62 TASK 801 SHOWED NO FAULTS. CLEANED CONTROL CABIN TEMP SENSOR AND FILTER AND PERFORMED CABIN TEMP CONTROL AND INDICATION - OPERATIONAL TEST PER B737-900 AMM 21-61-00-700-807-002 - ALL TESTS PASS.