Yamaha MTN850-A 2017 Service Manual page 498

Fault code No.
Item
Symptom
Order Item/components and probable cause
3 Front brake dragging
4 Defective hydraulic unit assembly
Fault code No. 42, 47
Fault code No.
Item
Symptom
Order Item/components and probable cause
1 Incorrect installation of the rear wheel
sensor (for fault code No. 42)
2 Incorrect rotation of the rear wheel
3 Rear brake dragging
4 Defective hydraulic unit assembly
ABS (ANTI-LOCK BRAKE SYSTEM)
41
Front wheel ABS (intermittent wheel speed pulses or incorrect
depressurization)
• 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.
Check or maintenance job
Check that the brake fluid pressure is correctly transmit-
ted to the brake caliper when the brake lever is operated
and that the pressure decreases when the lever is
released.
Refer to "CHECKING THE FRONT BRAKE DISCS" on
page 4-30.
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.
42
47
Rear wheel ABS (intermittent wheel speed pulses or incorrect
depressurization)
• Pulses from the rear wheel sensor are received intermittently
while the vehicle is traveling. (for fault code No. 42)
• Rear wheel will not recover from the locking tendency even
though the signal is transmitted from the ABS ECU to reduce the
hydraulic pressure.
Check or maintenance job
Check the components for looseness, distortion, and
bends.
Refer to "CHECKING THE REAR WHEEL" on page
4-21.
Check that there is no brake disc drag on the wheel and
make sure that it rotates smoothly.
Refer to "CHECKING THE REAR WHEEL" on page
4-21.
Check that the brake fluid pressure is correctly transmit-
ted to the brake caliper when the brake pedal is oper-
ated and that the pressure decreases when the pedal is
released.
Refer to "CHECKING THE REAR BRAKE DISC" on
page 4-43.
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.
8-141