What was found
LT BLEED LIGHT CAME ON DURING CLIMBOUT FROM 7,000 TO 15,000, NO BLEED EICAS MSG PRESENT. LIGHT EXTINGUISHED AFTER LEVEL OFF @15,000 AND BEFORE QRH WAS ACCOMPLISHED. PERFORMED AIR SUPPLY BITE TEST, FAULTING HIGH PRESSURE CONTROLLER ON LEFT SIDE, IAW AMM 36-23-00. REMOVED AND REPLACED LEFT ENGINE HIGH PRESSURE CONTROLLER IAW AMM 36-11-08. AIR SUPPLY BITE TEST AND LEAK CHECKED GOOD.