Yamaha YFM7FGPW Service Manual page 471

EPS (ELECTRIC POWER STEERING) SYSTEM
Fault code No. 21
Order Item/components and probable
cause
1 Connections
• Speed sensor coupler
• EPS control unit coupler at the
wire harness
2 Open or short circuit in wire har-
ness.
3 Defective speed sensor.
Fault code No. 22
Order Item/components and probable
cause
1 Connections
• EPS control unit coupler at the
wire harness
• ECU coupler at the wire harness
2 Open or short circuit in wire har-
ness.
3 Malfunction in ECU.
Symptom Speed sensor: open or short circuit detected.
Check or maintenance job
• Check the coupler for any pins
that may have pulled out.
• Check the locking condition of
the coupler.
• If there is a malfunction, repair it
and connect the coupler
securely.
• Repair or replace if there is an
open or short circuit.
• Between speed sensor coupler
and EPS control unit coupler.
(white–white)
• Execute the diagnostic mode.
(Code No.21)
• Replace if defective.
Refer to "SIGNALING SYSTEM".
Symptom No normal signals are received from the ECU.
Check or maintenance job
• Check the coupler for any pins
that may have pulled out.
• Check the locking condition of
the coupler.
• If there is a malfunction, repair it
and connect the coupler
securely.
• Repair or replace if there is an
open or short circuit.
• Between ECU coupler and EPS
control unit coupler.
(orange/white–orange/white)
Replace the ECU.
9 - 66
– +
ELEC
Reinstatement
method
Starting the
engine and acti-
vating the vehi-
cle speed
sensor by oper-
ating the vehicle
above 5 km/h, or
turning the main
switch to "OFF",
then to "ON",
and then delet-
ing the fault
codes. Refer to
"DIAGNOSTIC
MODE" and
"Deleting fault
codes".
Reinstatement
method
Turning the
main switch to
"OFF".