56_Immobilizer; Troubleshooting - Yamaha MT-09 2021 Service Manual

EAS20684

56_IMMOBILIZER

EAS33313

TROUBLESHOOTING

Item
Codes cannot be transmitted between the ECU and the immobilizer unit.
Cause
• Disconnected lead/cable.
• Open or short circuit in wire harness between immobilizer unit and ECU.
• Immobilizer unit malfunction.
• ECU malfunction.
Procedure
TIP
When a system malfunction occurs, the immobilizer system indicator light will flash. The DTC can be
identified by the flashing pattern. Refer to "HOW TO CHECK DTC" on page 9-27.
1. Connection of Immobilizer unit coupler and 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 2.
NO
→ Connect the coupler securely or replace the wire harness.
2. Turn the main switch to "ON".
Is DTC displayed?
YES
→ Go to step 3.
NO
→ Service is completed.
3. Wire harness continuity.
• Disconnect the immobilizer unit coupler "1", ECU coupler "2" and backup fuse 2 "3".
• Open circuit check
Between immobilizer unit coupler "1" and ECU
coupler "2"
Between immobilizer unit coupler "1" and back-
up fuse 2 holder "3"
Between immobilizer unit coupler "1" and
ground
yellow/blue–yellow/blue
red/green–red/green
black–ground
9-272
56_IMMOBILIZER