556 Engines · 22 Brands · 1955–2024
// Brand-Specific Diagnostics

Yamaha Fault Codes

Complete reference guide for interpreting Yamaha outboard flash patterns and alarms.

How to Read Yamaha Codes

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Long flashes (1.5s) count as 10. Short flashes (0.5s) count as 1. Example: 2 long + 3 short = Code 23.

← Try the Interactive Code Decoder

Yamaha Code Master List (23 Codes)

Code Fault Description Severity Required Action
1 Normal Operation NONE System OK.
13 Pulser Coil Signal HIGH Check ignition timing sensors and wiring.
14 Crank Position Sensor HIGH Check CKP sensor and flywheel alignment.
15 Engine Temp Sensor HIGH Check cooling system and thermostat operation.
17 Knock Sensor MEDIUM Check fuel quality and sensor wiring.
18 TPS Sensor MEDIUM Check throttle position sensor and wiring.
19 Battery Voltage MEDIUM Check battery condition and charging circuit.
22 Atmospheric Pressure Sensor MEDIUM Check BARO sensor and wiring.
23 Air Temp Sensor LOW Check IAT sensor and intake air path.
24 Camshaft Position Sensor HIGH Check CMP sensor and timing belt.
25 Fuel Pressure Signal HIGH Check fuel pumps and VST pressure.
26 Injector Signal HIGH Check fuel injector harness and ECU signal.
27 Water in Fuel HIGH Check fuel/water separator on engine.
28 Shift Position Switch MEDIUM Ensure motor is fully in neutral.
29 Intake Air Pressure Sensor HIGH Check MAP sensor and vacuum lines.
37 Intake Air Passage (ETV) HIGH Check electronic throttle valve operation.
39 Oil Pressure Sensor CRITICAL STOP ENGINE. Check oil pressure and level.
44 Engine Stop Lanyard INFO Check lanyard connection.
46 Overheat Switch CRITICAL Check for water pump failure or intake clogs.
49 Over-cooling MEDIUM Check for thermostat stuck open.
68 VCT (S-Bank) Timing HIGH Check Starboard variable cam timing solenoid.
69 VCT (P-Bank) Timing HIGH Check Port variable cam timing solenoid.
86 Immobilizer / Y-COP HIGH Check theft deterrent system and key fob.

Troubleshooting Yamaha Outboards

When your Yamaha outboard triggers an alarm or flashing sequence, it means the Electronic Control Unit (ECU) has detected a reading outside of safe operating parameters.

Always prioritize CRITICAL severity codes. If you receive a critical code, such as low oil pressure or critical overheat, you should shut down the engine immediately to prevent catastrophic powerhead failure. HIGH priority codes usually trigger the engine's Guardian (Limp) Mode to restrict RPMs so you can safely return to the dock.