FI SYSTEM DIAGNOSIS 4-83 Step 1 (When indicating P1657-H:) 1 1) Turn the ignition switch OFF. 2) Lift and support the fuel tank. (5-3) 3) Check the EXCVA position sensor coupler for loose or poor contacts. If OK, then check the EXCVA position sensor lead wire conti- nuity. 4) Disconnect the EXCVA position sensor coupler. 1 5) Check the continuity between Red wire C and Yellow wire A. If the sound is not heard from the tester, the circuit condition is OK. 6) Disconnect the ECM coupler. 1 E 7) Check the continuity between Yellow wire A and terminal 5. ! L 8) Also, check the continuity between B/Br wire B and terminal S. P EXCVA 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) S Is the continuity OK? YES Go to Step 4. NO Yellow wire shorted to VCC, or B/Br wire open 9) After repairing the trouble, clear the DTC using SDS tool. (4-27)