Speed Sensor: No Normal Signals Are Received From The Speed Sensor; Gear Position Switch: Open Or Short Circuit Is Detected; Clutch Switch: Open Or Short Circuit Is Detected - Yamaha YZF-R25 Service Manual

Fault code No.
Item
3 Wire harness continuity.
4 Defective lean angle sensor.
5 Malfunction in ECU.
Fault code No. 42
Fault code No.
Item
Fail-safe system
Diagnostic code No.
Tool display
Procedure
Probable cause of malfunc-
Item
tion and check
A-1 Locate the malfunction.
41
Lean angle sensor: open or short circuit detected.
Open or short circuit → Replace
the wire harness.
Between lean angle sensor cou-
pler and ECU coupler.
blue–blue
yellow/green–yellow/green
black/blue–black/blue
Refer to "CHECKING THE
LEAN ANGLE SENSOR" on
page 8-89.
Replace the ECU.
Refer to "REPLACING THE
ECU (engine control unit)" on
page 8-81.
42
Speed sensor: no normal signals are received from the speed
A
sensor.
B

Gear position switch: open or short circuit is detected.

C

Clutch switch: open or short circuit is detected.

Able to start engine
Able to drive vehicle
07
Speed sensor pulse
0–999
Check that the number increases when the rear wheel is rotated. The
number is cumulative and does not reset each time the wheel is stopped.
Maintenance job
Execute the diagnostic mode.
(Code No. 07)
Rotate the rear wheel by hand
and check that the indicated val-
ue increases.
Execute the diagnostic mode.
(Code No. 21)
When the transmission is in
neutral: "ON"
When the transmission is in
gear with the clutch lever re-
leased: "OFF"
When the transmission is in
gear with the clutch lever
squeezed: "ON"
8-53
FUEL INJECTION SYSTEM
Turn the main switch to "ON",
then to "OFF", and then back to
"ON".
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 4.
Turn the main switch to "ON",
then to "OFF", and then back to
"ON".
Fault code number is not dis-
played → Service is finished.
Fault code number is displayed
→ Go to item 5.
Confirmation of service com-
Value does not increase → Go
to item A-2.
Incorrect indication → Go to
item B-2 for the gear position
switch.
Incorrect indication → Go to
item C-2 for the clutch switch.
pletion