4-70 FI SYSTEM DIAGNOSIS Step 1 (When indicating P1654-L:) 1 1) Turn the ignition switch OFF. 2) Lift and support the fuel tank. (5-3) 3) Check the STP sensor coupler for loose or poor contacts. If OK, then check the STP sensor lead wire continuity. 4) Disconnect the STP sensor coupler. 1 5) Check the continuity between Y/W wire B and ground. 6) Also, check the continuity between Y/W wire B and B/Br wire C. If the sound is not heard from the tester, the circuit condi- tion is OK. 7) Disconnect the ECM coupler. 1 E ! 8) Check the continuity between Y/W wire B and terminal J. 9) Also, check the continuity between Red wire A and terminal L A. P STPS lead wire continuity: Continuity () 09900-25008: Multi-circuit tester set M 09900-25009: Needle pointed probe set A (Black) (Gray) Tester knob indication: Continuity test () ECM coupler (Harness side) Is the continuity OK? S YES Go to Step 1 (4-68) and go to Step 2. NO Red or Y/W wire open, or Y/W wire shorted to ground 10)After repairing the trouble, clear the DTC using SDS tool. (4-27)