Blink Code 39
Yamaha Motorcycle
Severity:What Does This Error Mean?
Blink code 39 on a Yamaha motorcycle means a fuel injector circuit has an open or short — the ECU detects abnormal current draw on an injector channel. The affected cylinder may run lean or not at all. Inspect the injector connectors and wiring before replacing.
Affected Models
- Yamaha YZF-R1
- Yamaha YZF-R6
- Yamaha MT-07
- Yamaha MT-09
- Yamaha FZ-09
Common Causes
- Loose injector connector after vibration
- Wiring damage from vibration or accident
- Failed injector coil (open or shorted)
- Damaged ECU output driver (rare)
- Corrosion in the injector connector pins
How to Fix It
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Locate the injectors.
On Yamaha bikes the injectors sit in the throttle bodies, one per cylinder. Each has a small electrical connector with two pins. Refer to the service manual for exact location on your model.
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Inspect each injector connector.
Disconnect each one in turn. Look for green oxidation, bent pins, or melted plastic. Clean with contact cleaner and reconnect firmly.
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Test injector resistance.
Disconnect and measure across the injector pins. Yamaha injectors typically read 11–14 ohms. Out-of-spec resistance confirms a failed injector.
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Inspect harness for damage.
Trace the wiring from each injector back along the harness. Look for chafed sections where the harness rubs against the frame. Damaged wiring needs repair before fitting a new injector.
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Have a dealer scan to identify the affected injector.
On multi-cylinder bikes blink 39 alone does not say which cylinder. A Yamaha service tool reads the specific injector channel. This avoids replacing a healthy injector by guesswork.
When to Call a Professional
If after wiring and connector checks the blink 39 persists, the injector itself has failed. Yamaha injectors are reliable — most cases trace to wiring issues. A dealer scan can identify which specific injector is implicated on multi-cylinder bikes.
Frequently Asked Questions
Can I ride my Yamaha with blink code 39?
Riding short distances is possible but the affected cylinder is misfiring or running lean — both damage the catalytic converter and pistons over time. Treat blink 39 as urgent; do not ride further than necessary.
How much does a Yamaha injector replacement cost?
Injectors cost USD 80–180 per cylinder depending on model. Labour is moderate — USD 150–300 for tank removal and throttle body access. Total typical cost USD 250–500 per affected injector.