Check:
- 1. throttle position sensor
- 2. speed sensor
Note: Before troubleshooting, remove the following part(-s):
- 1) rider seat
- 2) fuel tank
- 3) air filter case
- 4) left side cover
- Troubleshoot with the following special tool(-s).
- Pocket tester: 90890-03112
1. Throttle position sensor
Circuit diagram
![](https://motoinstruction.ru/img/yamaha/16/122650.jpg)
(15) Throttle position sensor; (16) Ignitor unit
1. Wire harness
Check the wire harness for continuity. Refer to "Circuit diagram".
Is the wire harness OK?
NO: Repair or replace the wire harness.
YES:
2. Throttle position sensor
Check the throttle position sensor for continuity. Refer to "Checking and adjusting the throttle position sensor".
Is the throttle position sensor OK?
NO: Replace the throttle position sensor.
YES: Replace the ignitor unit.
2. Speed sensor
Circuit diagram
![](https://motoinstruction.ru/img/yamaha/16/122651.jpg)
(16) Ignitor unit; (19) Speed sensor
1. Wire harness
Check the wire harness for continuity. Refer to "Circuit diagram".
Is the wire harness OK?
NO: Repair or replace the wire harness.
YES:
2. Speed sensor
Place the motorcycle on a suitable stand so that the rear wheel is elevated.
Connect the pocket tester (DC 20V) to the speed sensor connector.
- Tester (+) lead → White (1) terminal
- Tester (-) lead → Body earth
![](https://motoinstruction.ru/img/yamaha/16/122652.jpg)
Set the main switch to "ON".
Turn the rear wheel slowly.
Check the tester voltage (0V - 5V - 0V).
Is the speed sensor OK?
NO: Replace the speed sensor.
YES: Replace the ignitor unit.