2006-2009 Suzuki LT-R450 Service Manual, Page 167Get this manual
FI SYSTEM DIAGNOSIS
Step (When indicating P0120-L:) 1) Turn the ignition switch OFF2) Remove the fuel tank cover(c::::77-6) 3) Check the TP sensor coupler for loose or poor contacts If OK, then check the TP sensor lead wire continuity
4) Disconnect the TP sensor coupler5) Check the continuity between Yellow wire and ground6) Also, check the continuity between Yellow wire and BBr wire If the sound is not heard from the tester, the circuit condition is OK
7) Remove the headlight assembly(c::::74-33) 8) Disconnect the ECM coupler9) Check the continuity between Yellow wire and terminal 10)Also, check the continuity between Red wire and terminal