2009 Suzuki 400 LTZ Quad Sport Service Manual, Page 123Get this manual
1A-59 Engine General Information and Diagnosis: Troubleshooting NOTE After repairing the trouble, clear the DTC using SDS toolRefer to "Use of SDS Diagnosis Reset Procedures (Page 1A-12)"Step Action 1) Turn the ignition switch OFFYes No wire open or or BW wire open, shorted to groundor wire shorted to 2) Check the GP switch coupler for loose or poor contactsgroundIf OK, then measure the GP switch voltage If wire and connection are OK, Loose or poor intermittent trouble or contacts on the ECM faulty ECMcoupler If wire and connection are OK, replace the GP switch with new oneRefer to "Gear Position (GP) Switch Replace the ECM Removal and with known good Installation in Section one, and inspect it 5B (Page 5B-12)"I933H1110061-01 againRefer to "ECM 3) Make sure the engine stop switch is in the "RUN" Removal and positionInstallation in Section 1C (Page 1C-2)"4) Insert the needle pointed probe to the lead wire coupler5) Turn the ignition switch ON6) Measure the voltage at the wire side coupler between and BW wire, when shifting the gearshift lever from 1st to topSpecial tool (A): 0990025008 (Multi-circuit tester set) (B): 0990025009 (Needle pointed probe set) Tester knob indication Voltage) GP switch voltage 0.9 and more ((+) terminal: () terminal: BW) Recheck each terminal and wire harness for open circuit and poor connection (A) V