What was found
ICT - DIVERSION - FLT 0472 - DURING CRUISE EN ROUTE FROM DCA TO PHX ECAM INDICATED AN INTERMITTENT YELLOW HYDRAULIC RESERVOIR CLASS 1 OVERHEAT MESSAGE, AIRCRAFT DIVERTED TO ICT. MAINTENANCE TROUBLESHOT PER TSM 29-13-00-810-802 AND FOUND NO OVERHEAT OR FAULTS. AIRCRAFT CONTINUED ON TO PHX WHERE MAINTENANCE FOLLOWED UP WITH TROUBLESHOOTING BY PERFORMING A YELLOW HYDRAULIC SYSTEM INTERNAL LEAK CHECK PER AMM 29-00-00-280-003; SYSTEM BYPASS (APPROX 2 GPM) WAS WITHIN LIMITS. AS PRECAUTION THE YELLOW HYDRAULIC SYSTEM TEMPERATURE SWITCH WAS REPLACED PER AMM 29-33-11-401.