Mastering Yamaha Motorcycle Diagnostics: Understanding OBD2, DTC Fault Codes, and Troubleshooting Tips

When the check engine light unexpectedly illuminates on your motorcycle dashboard, you might be curious about its meaning and how to address the issue without having to visit a local Yamaha service center. In your quest for answers, you may have come across terms such as "on-board diagnostics," "OBD," "OBD II," or "OBD2," only to be daunted by the complexity of the subject matter.

History and Purpose of OBD2 Systems

In 1991, the California Air Resources Board decided to implement OBD technology to encourage cleaner air. The main objective of the OBD2 system was to detect malfunctions which could affect a vehicle's emissions and ensure compliance with required standards. Additionally, it serves as a valuable tool for diagnosing and troubleshooting various issues related to the engine, transmission, and other electronic systems within a vehicle.

Understanding OBD2 Systems in Vehicles

OBD2, or On-Board Diagnostics version 2, is the current standardised diagnostic system used around the world in vehicles, including cars, trucks, and motorcycles, manufactured since 1996. OBD2 improves upon its predecessor, OBD1, by providing enhanced compatibility, more precise diagnostics, and a broader range of diagnostic trouble codes (DTCs).

Using OBD2 Scanners with Yamaha Motorcycles

OBD2 systems utilise standardised DTCs that can be accessed using an OBD2 scanner or diagnostic tool, which connects to the vehicle's OBD2 port, most Yamaha's will need a 3 or 4 Pin to 16 Pin Yamaha OBD2 adapter cable. This port is typically located under the seat. Once connected, the scanner can read and clear fault codes, display real-time sensor data, and provide further diagnostic information.

If you don't already have a scanner we recommend buying the following Universal OBD II Scanner and Yamaha 4 Pin to 16 Pin OBD2 adapter cable from Amazon.

Yamaha Diagnostic Systems: Differences from OBD2 Standards

Unlike cars, Yamaha motorcycles do not adhere to the same OBD2 standards. Instead, they employ their own proprietary diagnostic systems. Although OBD2 became mandatory for cars in the United States in 1996 and later in other countries, the same regulation does not extend to motorcycles.

Compatibility of Yamaha Motorcycles with OBD2 Scanners

Around 2016, some Yamaha motorcycles began to show increased compatibility with generic OBD2 scanners, as the European Union and other regions mandated OBD-like systems for motorcycles to regulate emissions. It is crucial to note that compatibility varies across models, and you may require a specific adapter or scanner to read the diagnostic trouble codes on your Yamaha motorcycle.

Common Yamaha Fault Codes and Their Meanings

Code Description

11 No signal received from cylinder identification sensor (cam position sensor)

12 Crankshaft position sensor malfunction

13 Intake air pressure sensor malfunction

14 Intake air pressure sensor (open or short circuit)

15 Throttle position sensor malfunction

16 Throttle position sensor (open or short circuit)

17 EXUP servo motor malfunction

18 EXUP servo motor (open or short circuit)

19 Sidestand switch malfunction

20 Intake air pressure sensor (hose system) malfunction

21 Coolant temperature sensor malfunction

22 Intake air temperature sensor malfunction

23 Atmospheric pressure sensor malfunction

24 O2 sensor malfunction (only applicable to models with an O2 sensor)

25 Air intake pressure sensor #2 - open/short detected

26 Intake pressure sensor #2 - pipe clogged or throttle position sensor (TPS) stuck

27 Oil temperature sensor - open/short detected

28 Engine temperature sensor - open/short detected

29 Decompression solenoid (thermistor) - open/short detected

30 Lean angle sensor malfunction

31 Throttle position sensor (primary) malfunction

32 Throttle position sensor (secondary) malfunction

33 Ignition coil malfunction

34 Exhaust gas control valve malfunction

35 Immobilizer system malfunction

36 Faulty ignition coil 4th cylinder

37 Faulty linear control valve

38 Decompression solenoid - open/short detected

39 Injector malfunction

40 Lean angle sensor (open or short circuit) or ECU internal malfunction

41 Lean angle sensor malfunction

42 Speed sensor malfunction

43 Fuel system voltage (monitoring voltage for the fuel pump or injectors)

44 Error in the pre-delivery inspection process (typically appears in new motorcycles) / Error in the engine stop lanyard switch signal

45 O2 sensor malfunction (only applicable to models with an O2 sensor) / Shift cut-off

46 Power supply malfunction (voltage too low or too high) / Overheat switch

47 Battery voltage too low or too high

48 Throttle servo motor malfunction

49 Throttle servo motor (open or short circuit) / Over cooling

50 ECU internal malfunction

51 Faulty ECU data

52 ECU internal malfunction (memory check error)

53 ECU communication error

54 Sub-throttle valve actuator malfunction

55 Malfunction detected in the ECU

56 ECU internal malfunction (EEPROM error)

57 ECU communication error

58 ECU internal malfunction

59 Throttle servo motor malfunction / ECM memory (for trouble record only)

60 Throttle servo motor (open or short circuit)

61 Faulty ECU data

62 Sub-throttle position sensor malfunction / Low fuel pressure

63 Sub-throttle position sensor (open or short circuit)

64 Air induction system malfunction

66 Failure in trailer steering damper

68 VCT (S Bank) starboard valve pulley abnormal advance

69 VCT (P Bank) port valve pulley abnormal advance

70 ECU communication error / Error in idle control (engine may stall at idle after extended operation)

71 Sub-throttle valve actuator malfunction / S bank IN starboard IN cam position sensor

72 EXUP servo motor malfunction / P bank IN port IN cam position sensor

73 EXUP servo motor (open or short circuit)

75-82 RCS (Remote Control System) related issues

80 Grip warmer malfunction (only applicable to models with grip warmers)

81 Thumb warmer malfunction (only applicable to models with thumb warmers)

83 Sidestand switch malfunction (only applicable to models with a sidestand switch) / Trim/Tilt angle sensor

84 Neutral switch malfunction / RCS related issue

85 IDM (Ioncurrent Detection Module)

86 Y-COP immobilizer, theft deterrent

87 Remote Control System

98 Low fuel pressure

112 ETV ETS (ECM-sub)

113 ETV ETS (ECM-System)

Consulting Your Service Manual and Seeking Professional Help

Please note that this is not an exhaustive list, and the fault codes may vary depending on your specific Yamaha model. Consult your motorcycle's service manual for a complete list of fault codes and their meanings.

Once you have identified the fault code(s), you can use the information to diagnose and fix the issue. If you are unsure how to proceed, it's best to consult a professional mechanic.