Yamaha MTN850-A 2017, Service Manual, Page: 497 / 560

ABS (ANTI-LOCK BRAKE SYSTEM)
8-140
Fault code No. 34
Fault code No. 41
3 Open or short circuit in the wire harness
between the battery and the hydraulic unit
assembly
•
Replace if there is an open or short circuit.
•
Between ABS ECU coupler and starter relay coupler
(ABS motor fuse).
(red/blue–red/blue)
•
Between ABS ECU coupler and ground.
(black–black)
4 Defective hydraulic unit assembly If the above items were performed and no malfunctions
were found, replace the hydraulic unit assembly.
Refer to “ABS (ANTI-LOCK BRAKE SYSTEM)” on page
4-49.
Fault code No. 34
Item
Hydraulic unit assembly (short circuit in ABS motor power supply
circuit)
Symptom
Short circuit is detected in the motor power supply circuit in the
hydraulic unit assembly.
Order Item/components and probable cause Check or maintenance job
1 Defective hydraulic unit assembly Replace the hydraulic unit assembly.
Refer to “ABS (ANTI-LOCK BRAKE SYSTEM)” on page
4-49.
Fault code No. 41
Item
Front wheel ABS (intermittent wheel speed pulses or incorrect
depressurization)
Symptom
• Pulses from the front wheel sensor are received intermittently
while the vehicle is traveling.
• Front wheel will not recover from the locking tendency even
though the signal is transmitted from the ABS ECU to reduce the
hydraulic pressure.
Order Item/components and probable cause Check or maintenance job
1 Incorrect installation of the front wheel
sensor
Check the components for looseness, distortion, and
bends.
Refer to “CHECKING THE FRONT WHEEL” on page
4-10.
2 Incorrect rotation of the front wheel Check that there is no brake disc drag on the front wheel
and make sure that it rotates smoothly.
Refer to “CHECKING THE FRONT WHEEL” on page
4-10 and “CHECKING THE FRONT BRAKE DISCS” on
page 4-30.
Fault code No. 33
Item Hydraulic unit assembly (abnormal ABS motor power supply)
Symptom
Power is not supplied to the motor circuit in the hydraulic unit
assembly.
Order Item/components and probable cause Check or maintenance job