YAMAHA YZ250F SELF-DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE

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SELF-DIAGNOSTIC FUNCTION TABLE (FOR FUEL INJECTION SYSTEM)

Fault code

Item

Page

12

Crankshaft position sensor: no normal signals are received from the crankshaft position sensor.

Fault code No. 12

13

Intake air pressure sensor: open or short circuit detected.

Fault code No. 13

14

Intake air pressure sensor: hose system malfunction (clogged or detached hose).

Fault code No. 14

15

Throttle position sensor: open or short circuit detected.

Fault code No. 15

16

Throttle position sensor: stuck throttle position sensor is detected.

Fault code No. 16

21

Coolant temperature sensor: open or short circuit detected.

Fault code No. 21

22

Intake air temperature sensor: open or short circuit detected.

Fault code No. 22

30

The vehicle has overturned.

Fault code No. 30

33

Ignition coil: open or short circuit detected in the primary lead of the ignition coil.

Fault code No. 33

39

Injector: open or short circuit detected.

Fault code No. 39

41

ECU: built-in lean angle sensor malfunction.

Fault code No. 41

43

Fuel system voltage: incorrect voltage supplied to the main relay and CCU.

Fault code No. 43

44

EEPROM fault code number: an error is detected while reading or writing on EEPROM.

Fault code No. 44

46

Vehicle system power supply: normal voltage is not supplied to the ECU.

Fault code No. 46

50

ECU: faulty ECU memory.

Fault code No. 50

70

Engine forcibly stops when the vehicle is left idling for a long period of time.

Fault code No. 70

DIAGNOSTIC CODE: SENSOR OPERATION TABLE

Diagnostic code No.

Item

Display

Procedure

01

Throttle angle

Displays the throttle angle.

  • Fully closed position

  • 11–14

  • Check with throttle fully closed.

  • Fully opened position

  • 86–92

  • Check with throttle fully opened.

03

Pressure of suction pipe

Displays the intake air pressure.

  • Check the change of the intake pressure valve when the starter switch is pushed.

The atmospheric pressure is displayed on the Yamaha diagnostic tool.

05

Intake air temperature

Displays the intake air temperature.

Compare the actually measured intake air temperature with the Yamaha diagnostic tool display value.

06

Coolant temperature

Displays the coolant temperature.

Compare the actually measured coolant temperature with the Yamaha diagnostic tool display value.

08

Lean angle sensor

Displays the output voltage.

Remove the ECU, and incline it 45° or more.

  • Upright

  • 0.4–1.4 (V)

  • Overturn

  • 3.7–4.4 (V)

09

Monitor voltage

Displays the voltage of the external battery connected to the Yamaha diagnostic tool.

  • Approximately 12.0 (V)

—

21

Neutral switch

Operate the shift pedal.

  • Gear in neutral

  • ON

  • Gear not in neutral

  • OFF

25

Gear position switch

Operate the shift pedal.

  • Gear in 1st or 2nd

  • ON

  • Gear in other than 1st or 2nd

  • OFF

60

EEPROM fault code display

—

  • No fault

  • 00

  • CO adjustment valve

  • 01

  • Power Tuner injection correction setting 0–8, or Power Tuner ignition timing correction setting 0–8

  • 07

61

Malfunction history (△) code display *1

—

  • There is no history.

  • 00

  • There is some history.

  • Other: Displays the fault code of (△).

62

Malfunction history (△) code erasure *1

Replace all (△) with () by the operation start processing.

  • There is no history.

  • 00

  • There is some history.

  • Other: Displays the total number of (×) and (△).

64

Setting history display

Displays the presence or absence of the setting history by Power Tuner.

—

  • There is no history.

  • 00

  • There is some history.

  • 01

  • History is unknown (History data is damaged).

  • 02

65

Setting map erasure

Displays the presence or absence of the setting history by Power Tuner.

Erase all setting maps by the operation start processing.

  • There is no setting.

  • 00

  • There is some setting.

  • 01

70

Program version number

Displays a program version No.

—

*1: Symbols used in the explanations of the malfunction history

: Normal

×: There is currently a malfunction or abnormal condition.

△: A malfunction or abnormal condition occurred previously, but the affected system or component is currently operating normally.

DIAGNOSTIC CODE: ACTUATOR OPERATION TABLE

Diagnostic code No.

Item

Actuation

Procedure

30

Ignition coil

Actuates the ignition coil five times at one-second intervals.

“WARNING” on the Yamaha diagnostic tool blinks five times when the ignition coil is actuated.

Check that a spark is generated five times.

  • Connect an ignition checker.

36

Injector

Actuates the injector five times at one-second intervals.

“WARNING” on the Yamaha diagnostic tool blinks five times when the injector is actuated.

TIP: Before performing this operation, be sure to disconnect the fuel pump coupler.

Check that injector is actuated five times by listening for the operating sound.

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