2009 Suzuki 400 LTZ Quad Sport Service Manual, Page 112Get this manual
Engine General Information and Diagnosis: C21 (Use of mode select switch) Step Action 1) Turn the ignition switch OFF2) Check the IAT sensor coupler for loose or poor contactsIf OK, then measure the IAT sensor voltage at the wire side couplerYes Go to Step 2 1A-48
No Loose or poor contacts on the ECM coupler Open or short circuit in the Dg wire or BBr wire
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