What was found
UPON SELECTING FLAPS 1, THE RIGHT FLAP STAYED AT UP WHILE LEFT FLAPS WERE BETWEEN UP AND 1. LE DEVICES REMAINED UP. USED ALTERNATE FLAPS WHICH DROVE C/O LE DEVICES PER QRH. GROUNDED - YES. EMERGENCY LANDING DECLARED. FSEU BITE TEST SHOWS FAULT MSG 27-52260 "TE FLAP SNSR R". ACCOMPLISHED B737-900 FIM 27-51 TASK 820 "RIGHT FLAP POSITION TRANSMITTER DISAGREE PROBLEM" FAULT ISOLATION. REMOVED & REPLACED RT FLAP POSITION TRANSMITTER (T428) IAW AMM 27-58-01. ACCOMPLISHED FLAP POSITION TRANSMITTER ADJUSTMENT & TEST IAW AMM 27-58-01-820-801, OPS CK NORMAL.