Yamaha YZF-R125 Service Manual: Setting the diagnostic mode
1. Set the main switch to "OFF" and the engine stop switch to "
".
2. Disconnect the self-diagnosis signal connector "1", and then connect the FI diagnostic tool "2" as shown.
3. Disconnect the fuel pump coupler.
4. While pressing the "MODE" button, set the main switch to "ON".
NOTE:
- "DIAG" appears on the LCD of the FI diagnostic tool.
- "POWER" LED (Green) comes on.
5. Press the "UP" button to select the CO adjustment mode "CO" or the diagnostic mode "DIAG".
6. After selecting "DIAG", press the "MODE" button.
7. Select the diagnostic code number corresponding to the fault code number by pressing the "UP" and "DOWN" buttons.
NOTE:
- The diagnostic code number appears on the LCD (01-70).
- To decrease the selected diagnostic code number, press the "DOWN" button. Press the "DOWN" button for 1 second or longer to automatically decrease the diagnostic code numbers.
- To increase the selected diagnostic code number, press the "UP" button. Press the "UP" button for 1 second or longer to automatically increase the diagnostic code numbers.
8. Verify the operation of the sensor or actuator.
- Sensor operation The data representing the operating conditions of the sensor appear on the LCD.
- Actuator operation
Press the "MODE" button.
9. Set the main switch to "OFF" to cancel the diagnostic mode.
10.Disconnect the FI diagnostic tool and connect the self-diagnosis signal connector.
Diagnostic code table
Sensor operation table
Actuator operation table
Communication error with the FI diagnostic tool
Setting the normal mode
NOTE:
The engine speed, coolant temperature, and fault code, if detected, can be
displayed on the LCD of the
FI diagnostic tool when the tool is connected to the vehicle and is set to the
normal ...
Troubleshooting details
This section describes the measures per fault code number displayed on the FI
diagnostic tool. Check
and service the items or components that are the probable cause of the
malfunction following t ...
Other materials:
Checking the cylinder and piston
1. Check:
Piston wall
Cylinder wall
Vertical scratches Replace the
cylinder,
and replace the piston and piston rings as a
set.
2. Measure:
Piston-to-cylinder clearance
a. Measure cylinder bore "C" with the cylinder
bore gauge.
NOTE:
Measure cylinder bore "C" by takin ...
Checking the valve springs
The following procedure applies to all of the
valve springs.
1. Measure:
Valve spring free length "a"
Out of specification Replace the valve
spring.
2. Measure:
Compressed valve spring force "a"
Out of specification Replace the valve
spring.
b. Installed length
3. ...
Checking the crankshaft position sensor
1. Disconnect:
Crankshaft position sensor coupler
(from the wire harness)
2. Check:
Crankshaft position sensor resistance
Out of specification Replace
the crankshaft
position sensor/stator assembly.
a. Connect the pocket tester ( × 100) to the
crankshaft position sensor c ...