Yamaha YZF-R125 Service Manual: Circuit diagram
2. Crankshaft position sensor
4. Main fuse
5. Main switch
6. Radiator fan motor fuse
8. Sidestand switch
9. Battery
17.Engine stop switch
19.Intake air pressure sensor
20.Intake air temperature sensor
21.Throttle position sensor
22.Coolant temperature sensor
23.Lean angle sensor
24.Self-diagnosis signal connector
25.ECU (engine control unit)
26.Ignition coil
27.Spark plug
28.FID (fast idle solenoid)
29.Fuel injector
30.Fuel pump
32.Radiator fan motor relay
33.Radiator fan motor
63.Engine trouble warning light
64.Ignition fuse
66.Signaling system fuse
67.Speed sensor
Ecu self-diagnostic function
The ECU is equipped with a self-diagnostic function in order to ensure that
the fuel injection system is
operating normally. If this function detects a malfunction in the system, it
immediately o ...
Other materials:
Troubleshooting
The ignition system fails to operate (no spark or intermittent spark).
NOTE:
Before troubleshooting, remove the following part(s):
1. Seats
2. Fuel tank
3. Right side cover
4. Left side panel
5. Left upper side cowling
...
Troubleshooting method
The engine operation is not normal and the
engine trouble warning light comes on.
1. Check:
Fault code number
a. Check the fault code number displayed on
the FI diagnostic tool.
b. Identify the faulty system with the fault code.
Refer to "Self-Diagnostic Function table".
c. Identi ...
Checking the spark plug
The spark plug is an important engine
component, which is easy to check.
Since heat and deposits will cause any
spark plug to slowly erode, the spark
plug should be removed and checked
in accordance with the periodic maintenance
and lubrication chart. In addition,
the condition of the ...