Yamaha MT-03 Service Manual

Also see for MT-03: Owner's manual Owner's manual Owner's manual

7-36FUEL INJECTION SYSTEMFault code No. 43 Symptom The ECU is unable to monitor the battery voltage.Used diagnostic code No. 09, 50 (fuel system voltage)Order Item/components Check or maintenance job Restore method1 Coupler connectionsFuel injection system relay cou-plerWiring harness ECU couplerCheck the couplers for any pins that may havepulled out.Check that the couplers are securely locked.If necessary, repair the coupler or securely con-nect it.Reinstated by start-ing the engine andoperating it at idle.2 Defective main relay Replace the relay if it is defective.3 Open or short circuit in the wire har-nessExecute the diagnostic mode. (Code No. 09)Repair or replace if there is an open or short cir-cuit:between battery and fuel injection system fuseRed - Redbetween fuel injection system fuse and fuel injec-tion system relayBrown - Brownbetween fuel injection system relay and ECURed/Blue - Red/Bluebetween battery and main switchRed - Redbetween main switch and ignition fuseBrown/Blue - Brown/Bluebetween ignition fuse and engine stop switchRed - Redbetween engine stop switch and fuel injectionsystem relayRed/Black - Red/Blackbetween fuel injection system relay and ECUBlue/Red - Blue/Red4 Malfunction or open circuit in thefuel injection system relayExecute the diagnostic mode. (Code No. 50)Replace if defective.1. Remove the relay unit.2. Connect the pocket tester and battery(12 V) to the relay terminals as shown.3. Does the diode have continuity betweenbrown and red/blue?If there is no malfunction with the fuel injectionsystem relay, replace the ECU.14123(Ω x 1)• Positive battery terminal → Red/Black “1”• Negative battery terminal → Blue/Red “2”• Positive tester probe → Brown “3”• Negative tester probe → Red/Blue“4”