P0638; Troubleshooting - Yamaha MT-09 2021 Service Manual

EAS20599

P0638

EAS33079

TROUBLESHOOTING

Item
YCC-T drive system: malfunction detected.
Fail-safe system
• Able/Unable to start engine
• Able/Unable to drive vehicle
Procedure
1. Connection of throttle servo motor coupler.
• Check the locking condition of the coupler.
• Disconnect the coupler and check the pins (bent or broken terminals and locking condition of the
pins).
Is the coupler condition normal?
YES
→ Go to step 2.
NO
a. Connect the coupler securely or replace the wire harness.
b. Turn the main switch to "ON", and then check the condition of the DTC using the malfunction
mode of the YDT.
Is it in the "Recovered" condition?
YES
→ Go to step 7, and complete the service.
NO
→ Go to step 2.
2. Connection of ECU coupler.
• Check the locking condition of the coupler.
• Disconnect the coupler and check the pins (bent or broken terminals and locking condition of the
pins).
Is the coupler condition normal?
YES
→ Go to step 3.
NO
a. Connect the coupler securely or replace the wire harness.
b. Turn the main switch to "ON", and then check the condition of the DTC using the malfunction
mode of the YDT.
Is it in the "Recovered" condition?
YES
→ Go to step 7, and complete the service.
NO
→ Go to step 3.
9-205
P0638