YAMAHA YZ250F FUEL INJECTION SYSTEM FAULT CODE (TROUBLESHOOTING)

Fail-safe system

Unable to start engine

Unable to drive vehicle

Diagnostic code No.

—

Diagnostic tool display

—

Procedure

—

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Connection of crankshaft position sensor coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Crank the engine, and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Connection of wire harness ECU coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Crank the engine, and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Wire harness continuity.

Open or short circuit → Replace the wire harness.

Between the crankshaft position sensor coupler and ECU coupler.

gray–gray

black/blue–black/blue

Crank the engine, and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 4.

4

Mounted condition of crankshaft position sensor.

Check for looseness or pinching.

Check the gap (0.85 mm (0.0335 in)) between the crankshaft position sensor and the pickup rotor.

Improperly mounted sensor → Remount or replace the sensor.

Refer to GENERATOR.

Crank the engine, and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 5.

5

Defective crankshaft position sensor.

Check the crankshaft position sensor.

Refer to CHECKING THE CRANKSHAFT POSITION SENSOR.

Crank the engine, and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 6.

6

Faulty ECU.

Replace the ECU.

Service is finished.

7

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

• If fault code numbers 13 and 14 are both displayed, perform checkup and repair jobs for fault code number 13 first.

• Before troubleshooting, disconnect the starter motor lead from the starter relay.

Fail-safe system

Able to start engine

Able to drive vehicle

Diagnostic code No.

03

Diagnostic tool display

Displays the intake air pressure.

Procedure

The atmospheric pressure is displayed on the Yamaha diagnostic tool.

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Connection of intake air pressure sensor coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Connection of wire harness ECU coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Wire harness continuity.

Open or short circuit → Replace the wire harness.

Between intake air pressure sensor coupler and ECU coupler.

pink/black–pink/black

blue–blue

black/blue–black/blue

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 4.

4

Mounted condition of intake air pressure sensor.

Check for looseness or pinching.

Check the mounted position for correctness.

Improperly mounted sensor → Remount or replace the sensor.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 5.

5

Defective intake air pressure sensor.

Execute the diagnostic mode. (Code No. 03)

Atmospheric pressure at the current altitude and weather conditions is indicated.

0 m above sea level: About 101 kPa (about 3.63 V)

1000 m above sea level:
About 90 kPa (about 3.30 V)

2000 m above sea level:
About 80 kPa (about 3.00 V)

3000 m above sea level:
About 70 kPa (about 2.70 V)

Abnormal display → Intake air pressure sensor is defective → Replace the intake air pressure sensor.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 6.

6

Faulty ECU.

Replace the ECU.

Service is finished.

7

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

If fault code numbers 13 and 14 are both displayed, perform checkup and repair jobs for fault code number 13 first.

Fail-safe system

Able to start engine

Able to drive vehicle

Diagnostic code No.

03

Diagnostic tool display

Displays the intake air pressure.

Procedure

The atmospheric pressure is displayed on the Yamaha diagnostic tool.

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

The intake air pressure sensor hose is damaged, disconnected, clogged, twisted or bent.

Repair or replace the sensor hose.

Start the engine and let it idle for approximately 5 seconds (fully close the throttle valve).

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 3 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Defective intake air pressure sensor.

Execute the diagnostic mode. (Code No. 03)

Atmospheric pressure at the current altitude and weather conditions is indicated.

0 m above sea level: About 101 kPa (about 3.63 V)

1000 m above sea level: About 90 kPa (about 3.30 V)

2000 m above sea level: About 80 kPa (about 3.00 V)

3000 m above sea level: About 70 kPa (about 2.70 V)

Value does not change during cranking → Intake air pressure sensor replacement.

Service is finished.

3

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

Before troubleshooting, disconnect the starter motor lead from the starter relay.

Fail-safe system

Able to start engine

Able to drive vehicle

Diagnostic code No.

01

Diagnostic tool display

Displays the throttle angle.

Procedure

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Connection of throttle position sensor coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Connection of wire harness ECU coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Wire harness continuity.

Open or short circuit → Replace the wire harness.

Between throttle position sensor coupler and ECU coupler.

yellow–yellow

blue–blue

black/blue–black/blue

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 4.

4

Mounted condition of throttle position sensor.

Check for looseness or pinching.

Check the mounted position for correctness.

Improperly mounted sensor → Remount or replace the sensor.

Refer to ADJUSTING THE THROTTLE POSITION SENSOR.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 5.

5

Applied voltage of throttle position sensor lead.

Check the applied voltage.

(black/blue–blue)

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 6.

Location of disconnected lead

Output voltage

Disconnected ground lead

5 V

Disconnected output lead

0 V

Disconnected power supply lead

0 V

6

Defective throttle position sensor.

Execute the diagnostic mode. (Code No. 01)

When the throttle is fully closed, 11–14 displays.

When the throttle is fully opened, 86–92 displays.

Incorrect display range → Replace the throttle position sensor.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 7.

7

Faulty ECU.

Replace the ECU.

Service is finished.

8

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

• If fault code numbers 15 and 16 are both displayed, perform checkup and repair jobs for fault code number 15 first.

• Before troubleshooting, disconnect the starter motor lead from the starter relay.

Fail-safe system

Able to start engine

Able to drive vehicle

Diagnostic code No.

01

Diagnostic tool display

Displays the throttle angle.

Procedure

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Mounted condition of throttle position sensor.

Check for looseness or pinching.

Check the mounted condition for correctness.

Improperly mounted sensor → Remount or replace the sensor.

Refer to ADJUSTING THE THROTTLE POSITION SENSOR.

Start switch to ON (main relay ON) and open and close the throttle several times.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 4 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Defective throttle position sensor.

Execute the diagnostic mode. (Code No. 01)

When the throttle is fully closed, 11–14 displays.

When the throttle is fully opened, 86–92 displays.

Incorrect display range → Replace the throttle position sensor.

Start switch to ON (main relay ON) and open and close the throttle several times.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 4 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Faulty ECU.

Replace the ECU.

Service is finished.

4

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

• Make sure that the machine is completely cold before checking the coolant temperature sensor.

• Before troubleshooting, disconnect the starter motor lead from the starter relay.

Fail-safe system

Able to start engine

Able to drive vehicle

Diagnostic code No.

06

Diagnostic tool display

Displays the coolant temperature.

Procedure

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

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Connection of coolant temperature sensor coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Connection of wire harness ECU coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Wire harness continuity.

Open or short circuit → Replace the wire harness.

Between coolant temperature sensor coupler and ECU coupler.

green/white–green/white

black/blue–black/blue

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 4.

4

Mounted condition of coolant temperature sensor.

Check for looseness or pinching.

Check the mounted position for correctness.

Improperly mounted sensor → Remount or replace the sensor.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 5.

5

Defective coolant temperature sensor.

Execute the diagnostic mode. (Code No. 06)

When the machine is cold, displayed temperature is close to the ambient temperature.

Improper display → Replace the coolant temperature sensor.

Refer to RADIATOR.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 6.

6

Faulty ECU.

Replace the ECU.

Service is finished.

7

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

• Make sure that the machine is completely cold before checking the intake air temperature sensor.

• Before troubleshooting, disconnect the starter motor lead from the starter relay.

Fail-safe system

Able to start engine

Able to drive vehicle

Diagnostic code No.

05

Diagnostic tool display

Displays the intake air temperature.

Procedure

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

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Connection of intake air temperature sensor coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Connection of wire harness ECU coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Wire harness continuity.

Open or short circuit → Replace the wire harness.

Between intake air temperature sensor coupler and ECU coupler.

brown/white–brown/white

black/blue–black/blue

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 4.

4

Mounted condition of intake air temperature sensor.

Check for looseness or pinching.

Check the mounted position for correctness.

Improperly mounted sensor → Remount or replace the sensor.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 5.

5

Defective intake air temperature sensor.

Execute the diagnostic mode. (Code No. 05)

When the machine is cold, displayed temperature is close to the ambient temperature.

Improper display → Replace the intake air temperature sensor.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 7 and finish the service.

Condition is “Detected”→ Go to item 6.

6

Faulty ECU.

Replace the ECU.

Service is finished.

7

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

Before troubleshooting, disconnect the starter motor lead from the starter relay.

Fail-safe system

Unable to start engine

Unable to drive vehicle

Diagnostic code No.

08

Diagnostic tool display

Displays the lean angle sensor output voltage.

Procedure

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

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

The vehicle has overturned.

Raise the vehicle upright.

Start switch to ON (main relay ON), wait 10 seconds, then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 4 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Mounted condition of ECU.

Check for looseness or pinching.

Check the mounted condition for correctness.

Improperly mounted ECU → Remount the ECU.

Start switch to ON (main relay ON), wait 10 seconds, then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 4 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Faulty ECU.

Execute the diagnostic mode. (Code No. 08)

When the vehicle is upright:

0.4–1.4 (V)

When the vehicle is overturned:

3.7–4.4 (V)

Improper display → Replace the ECU.

Service is finished.

4

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

Fail-safe system

Unable to start engine

Unable to drive vehicle

Diagnostic code No.

30

Actuation

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.

Procedure

Check that a spark is generated five times.

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Connection of ignition coil coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Connection of wire harness ECU coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Connection of sub wire harness coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the sub wire harness.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 4.

4

Wire harness continuity.

Open or short circuit → Replace the wire harness.

Between ignition coil coupler and ECU coupler.

orange–orange

red–red/blue

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 5.

5

Mounted condition of ignition coil.

Check for looseness or pinching.

Check the mounted condition for correctness.

Improperly mounted sensor → Remount or replace the ignition coil.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 6.

6

Defective ignition coil. (test the primary coils for continuity)

Check the primary resistance of the ignition coil.

Refer to CHECKING THE IGNITION COIL.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 8 and finish the service.

Condition is “Detected”→ Go to item 7.

7

Faulty ECU.

Execute the diagnostic mode. (Code No. 30)

No spark → Replace the ECU.

Service is finished.

8

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

Disconnect the fuel pump coupler when this diagnostic tool is used.

Fail-safe system

Unable to start engine

Unable to drive vehicle

Diagnostic code No.

36

Actuation

Actuates injector five times at one-second intervals.

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

Procedure

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

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Connection of injector coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Defective injector.

Check the injector.

Refer to CHECKING THE INJECTOR.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Connection of wire harness ECU coupler.

Check the locking condition of the coupler.

Disconnect the coupler, and check the pins (for bent or broken terminals and locking condition of the pins).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 4.

4

Wire harness continuity.

Open or short circuit → Replace the wire harness.

Between injector coupler and ECU coupler.

red/black–red/black

Between injector coupler and starter relay.

red/blue–red/blue

red–red

red/yellow–red/yellow

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 5.

5

Faulty ECU.

Replace the ECU.

Service is finished.

6

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

Fail-safe system

Unable to start engine

Able to drive vehicle

Diagnostic code No.

08

Diagnostic tool display

Displays the lean angle sensor output voltage.

Procedure

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

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Faulty ECU.

Replace the ECU.

Service is finished.

Fail-safe system

Able to start engine

Able to drive vehicle

Diagnostic code No.

09

Diagnostic tool display

Fuel system voltage

Approximately 12.0 (V)

Procedure

Disconnect the main relay, and push the start switch.

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Connection of main relay 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).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Press the start switch and the engine stop switch alternately to switch the power supply (= main relay) from “ON → OFF → ON”.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Connection of wire harness 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).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Press the start switch and the engine stop switch alternately to switch the power supply (= main relay) from “ON → OFF → ON”.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Wire harness continuity.

Open or short circuit → Replace the wire harness.

Between battery terminal and main relay.

red–red

red–red/white

Between main relay coupler and ECU coupler.

brown–brown

blue/red–blue/red

Press the start switch and the engine stop switch alternately to switch the power supply (= main relay) from “ON → OFF → ON”.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 4.

4

Defective main relay.

No operating sound → Replace the main relay.

Or execute the diagnostic mode. (Code No. 09)

Fuel system voltage is below 3 V → Replace the main relay.

Press the start switch and the engine stop switch alternately to switch the power supply (= main relay) from “ON → OFF → ON”.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 5.

5

Malfunction in ECU.

Replace the ECU.

Service is finished.

6

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

Before troubleshooting, disconnect the starter motor lead from the starter relay.

Fail-safe system

Able/Unable to start engine

Able/Unable to drive vehicle

Diagnostic code No.

60

Diagnostic tool display

Displays the location of the abnormal portion of the EEPROM data.

Procedure

—

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Identification of malfunctioning point.

Execute the diagnostic mode. (Code No. 60)

00: Go to item 4.

01: Go to item 2.

07: Go to item 3.

2

“01” is indicated in diagnostic mode. (Code No. 60)

EEPROM data error for adjustment of CO concentration.

Change the CO concentration, and rewrite in EEPROM.

After this adjustment, push the engine stop switch, and then push the start switch.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 5 and finish the service.

Condition is “Detected”→ Repeat item 1.

If the same number is indicated, go to item 4.

3

“07” is indicated in diagnostic mode. (Code No. 60)

EEPROM data error for setting tool adjustment values for fuel injection amount or ignition timing.

Erase the setting map in the diagnostic mode. (Code No. 65)

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 5 and finish the service.

Condition is “Detected”→ Repeat item 1.

If the same number is indicated, go to item 4.

4

Faulty ECU.

Replace the ECU.

Service is finished.

5

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

Fail-safe system

Able/Unable to start engine

Able/Unable to drive vehicle

Diagnostic code No.

—

Diagnostic tool display

—

Procedure

—

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Connection of rectifier/regulator 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).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 2.

2

Connection of AC magneto 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).

Improperly connected → Connect the coupler securely, or repair/replace the wire harness.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 3.

3

Wire harness continuity.

Open or short circuit → Replace the wire harness.

Between rectifier/regulator coupler and battery terminal.

red–red

black–black

Between rectifier/regulator coupler and AC magneto coupler.

white–white

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 4.

4

Defective AC magneto.

Check the AC magneto.

Refer to CHECKING THE STATOR COIL.

Start the engine and let it idle for approximately 5 seconds.

Check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Condition is “Recovered”→ Go to item 6 and finish the service.

Condition is “Detected”→ Go to item 5.

5

Faulty ECU.

Replace the ECU.

Service is finished.

6

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.

Before troubleshooting, disconnect the starter motor lead from the starter relay.

Fail-safe system

Unable to start engine

Unable to drive vehicle

Diagnostic code No.

—

Diagnostic tool display

—

Procedure

—

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Faulty ECU.

Replace the ECU.

Start switch to ON (main relay ON), and then check the condition of the fault code using the malfunction mode of the Yamaha diagnostic tool.

Check that the fault code number is not displayed.

It is not a malfunction.

If the engine is forcibly stopped by leaving idle, the recovered state is recorded by malfunction mode.

Fail-safe system

—

Unable to drive vehicle

Diagnostic code No.

—

Diagnostic tool display

—

Procedure

—

Item

Probable cause of malfunction and check

Maintenance job

Confirmation of service completion

1

Delete the fault code.

Confirm that the fault code has a condition of “Recovered” using the Yamaha diagnostic tool, and then delete the fault code.