Yamaha Fz6 N Service Manual

FEATURES
1-12
WARNING
EWA4S81004
The braking of the vehicle, even in the worst case, is principally executed when the vehicle is 
advancing straight ahead. During a turn, sudden braking is liable to cause a loss of traction 
of the tires. Even in vehicles equipped with ABS, overturning of the vehicle cannot be pre-
vented if it is braked suddenly.
The ABS functions to prevent the tendency of the wheel to lock by controlling the brake fluid pres-
sure. However, if there is a tendency of the wheel to lock...

FEATURES
1-13
ABS block diagram
EAS4S81008
ABS COMPONENT FUNCTIONS
Wheel sensors and wheel sensor rotors
Wheel sensors “1” detect the wheel rotation speed and transmit the wheel rotation signal to the ABS 
ECU.
Each wheel sensor is composed of a permanent  magnet and a hall IC. The wheel sensors are 
installed in the sensor  housing for each wheel.
Sensor rotor “2” is pressed in the inner side of  the front wheel hub and rotate with the wheel.
Sensor rotor “3” is install on the rear hub and rotate  with...

FEATURES
1-14
ABS warning light
The ABS warning light “1” comes on to warn the rider if a malfunction in the ABS occurs.
When the main switch is turned to “ON”, the ABS warning light comes on for 2 seconds, then goes 
off, so that the rider can check if the ABS warning light is disconnected and check if the ABS is oper-
ating properly.
CAUTION:
ECA4S81005
If the rear wheel is raced with the vehicle on the suitable stand, the ABS warning light may 
flash or come on. If this occurs, turn the main switch...

FEATURES
1-15
Hydraulic unit
The hydraulic unit “1” is composed of three hydraulic control valves (each with a solenoid valve and 
flow control valve), two buffer chambers, two hydraulic pumps, and an ABS motor. The hydraulic unit 
adjusts the front and rear wheel brake fluid pressure  to control the wheel speed according to signals 
transmitted from the ABS ECU.
 Hydraulic control valve
The hydraulic control valve is composed of a flow control valve and solenoid valve.
When the ABS is activated, the...

FEATURES
1-16
 Buffer chamberThe buffer chamber accumulates the brake fluid  that is depressurized while the ABS is operating.
1. Orifice
2. Solenoid valve 3. Spool
4. Flow control valve
1. Buffer chamber (pressurized)
2. Buffer chamber (depressurized)
3. Raised piston 

FEATURES
1-17
ABS ECU (electronic control unit)
The ABS ECU “1” controls the ABS and is installed under the fuel tank. To protect the ABS ECU 
from water damage, it is protected by a cover “2”.
As shown in the block following diagram, the ABS ECU receives wheel sensor signals from the front 
and rear wheels and also receives si gnals from other monitor circuits.
1. Battery
2. Engine stop switch
3. Starting circuit cut-off relay
4. Sidestand switch
5. Starter relay
6. Starter motor 7. Start switch
8....

FEATURES
1-18
The necessary actions are confirmed using the monitor circuit and control signals are transmitted to 
the hydraulic unit and ABS motor relay.
ABS control operation
The ABS control operation performed in the ABS  ECU is divided into the following two parts.
 Hydraulic control
 Self-diagnosis
These operations are performed once every 8/1000th of a second. When a failure is detected in the 
ABS, a malfunction code is stored  in the memory of the ABS ECU for easy problem identification 
and...

FEATURES
1-19
Composition and operation
The ABS motor relay is activated by signals transmitted from the ABS ECU and operates simulta-
neously when the ABS starts to reduc e the hydraulic pressure of the brake fluid. If the solenoid relay 
is turned off, the ABS motor relay is also deactivated and the motor stops operating if there is a mal-
function.
EAS4S81009
ABS OPERATION
The ABS hydraulic circuit consists of two system s: the front wheel, and rear wheel. The following 
describes the front system...

FEATURES
1-20
Therefore, when the brake lever is squeezed, the hydraulic pressure in the brake master cylinder 
increases and the brake fluid is sent to the brake caliper via port A “7” and port B “9”.
At this time, the inlet and outlet check valves of the pump close the lines and brake fluid is not sent.
As a result, the brake master cylinder directly pr essurizes the brake caliper during normal braking. 
When the brake lever is released, the brake fluid in the brake caliper returns to the brake master...

FEATURES
1-21
Emergency braking (ABS activated)
1.Depressurized stateWhen the front wheel is about to lockup, port D “11” of the solenoid valve is opened by the 
“depressurization” signal transmitted from the ABS  ECU. When this occurs, the spool of the flow 
control valve compresses the return spring and closes port B “9”. Brake fluid that has entered 
through port A “7” is restricted by the orifice “10” and the brake fluid is sent to the brake caliper via 
port C “13” and port D “11”, and the buffer...