2009 Suzuki 400 LTZ Quad Sport Service Manual, Page 117Get this manual
1A-53 Engine General Information and Diagnosis: C23 (Use of mode select switch) Step Action 1) Turn the ignition switch OFF2) Remove the left side coverRefer to "Exterior Parts Removal and Installation in Section 9D (Page 9D-4)"3) Check the TO sensor coupler for loose or poor contactsIf OK, then measure the TO sensor resistanceYes Go to Step 2No Replace the TO sensor with new oneRefer to "TO Sensor Removal and Installation in Section 1C (Page 1C6)" I933H1110053-01