What was found
FLIGHT 2177. CKPT, FWD, AFT CABIN TEMP UNABLE TO BE CONTROLLED. BOTH HOT & COLD AIR. TEMP VALUES (ACTUAL) FLICKERING VALUES BTWN SUB 10 DEGREES C, & ABOVE 20 DEGREES C. BLEED PRESSURES NORMAL. DIVERTED & ACCOMP UNEVENTFUL LANDING. REMOVED FROM SERVICE. INTERROGATED CMC, NO FAULT CODES FOUND. PERFORMED COCKPIT TEMP CONTROL OPS TEST IAW AMM 21-61-00-710-801-A. PERFORMED PAX CABIN TEMP CONTROL OPS TEST IAW AMM 21-62-00-710-801-A. BOTH OPS TESTED GOOD. FOR FURTHER TROUBLESHOOTING, PERFORMED BOTH COCKPIT & PAX CABIN TEMP CONTROL TESTS USING ENGS AS PNEUMATIC SOURCE, OPS TESTED GOOD. TEMP VALUES (ACTUAL) ON ECS SYNOPTICS PAGE ON MFD DID NOT FLUCTUATE OR FLICKER DURING TESTS. COULD NOT DUPLICATE. RETURNED TO SERVICE. NO PARTS REPLACED.