Yamaha Fz6 N Service Manual

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-88
Malfunc-
tion code Problem Check point Reference
11* Front wheel sensor signal is not 
received properly.
 Installation of the front wheel 
sensor
 Front wheel sensor lead and cou- pler
 ABS wire harness circuit
 Front wheel sensor rotor Malfunction 
code 11
12 Rear wheel sensor signal is not 
received properly.
 Installation of the rear wheel sen-
sor
 Rear wheel sensor lead and cou-
pler
 ABS wire harness circuit
 Rear wheel sensor rotor Malfunction 
code 12
13 (front) 14 (rear) Incorrect signal is detected by the 
front (13) or rear (14) wheel sen-
sor.
 Wheel sensor installation
 Wheel sensor housings
 Wheel sensor rotors Malfunction 
codes 13 
(front wheel) 
and 14 (rear 
wheel)
15 (front) 16 (rear) No continuity in the front or rear 
wheel sensor circuits
 Continuity of sensor circuits
 ABS wire harness circuit
 Connection of sensor coupler Malfunction 
codes 15 
(front wheel 
sensor) and 
16 (rear 
wheel sen-
sor)
18 Missing serration of sensor rotor  Sensor rotor Malfunction 
code 18
21 Disconnection and s
hort-circuit of 
hydraulic unit solenoid  Wire harness circuit
 Hydraulic unit solenoid coupler
 Hydraulic unit solenoid
 Battery terminal is disconnect Malfunction 
code 21
22 Starter motor monitor malfunction  Wire harness circuit
 Replace the ABS ECU. Malfunction 
code 22
24 Stop light failure
(Brake system circuit has failure.)
 Adjust the brake light switch.
 Brake light switch
 Bulb has burned out.
 Check the wire harness for the 
brake light system circuit. Malfunction 
code 24 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-89
25At the beginning of running, there 
is no pulse from the front wheel 
sensor.
 Rear wheel was rotated with the 
vehicle on the centerstand.
 Rear wheel was wheel-spin.
 Wheelie tried
 Defective installation of the wheel  speed sensor for the front wheel Malfunction 
code 25
26 (front) 27 (rear) Same as malfunction code 13 and 
14
(Running on extremely uneven 
roads)
 Same as malfunction code 13 
and 14 Malfunction 
code 26 
(front) and 27 
(rear)
28 Other malfunctions
(Malfunction of the memory in ABS 
ECU)
 Replace the ABS ECU Malfunction 
code 28
31 Disconnection is detected between 
the battery and ABS ECU system.
 ABS motor fuse
 ABS wire harness circuit 
(between the battery and ABS 
ECU)
 ABS ECU coupler Malfunction 
code 31
32 Circuit malfunction of ABS ECU is 
detected.
Upstream side of the solenoid 
relay  Wire harness circuit
 Replace the ABS ECU.
Malfunction 
code 32
33 Defective operation of the ABS 
motor is detected. (ABS motor 
stops and will not rotate.)
 ABS wire harness circuit
 ABS motor coupler
 ABS motor relay
 ABS motor circuit
 ABS motor fuse Malfunction 
code 33
34 Defective operation of the ABS 
motor is detected. (ABS motor 
keeps running and will not stop.)
 ABS motor relay
 ABS wire harness circuit
 ABS motor circuit Malfunction 
code 34
Malfunc-
tion code Problem Check point Reference 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-90
35Disconnection is detected between 
the ABS ECU and solenoid sys-
tem.
Downstream side of the solenoid 
relay  ABS harness circuit (from ABS 
ECU to the solenoid)
 Solenoid coupler
 Battery terminal is disconnected. Malfunction 
code 35
41 Front wheel will not recover from 
the locking tendency even though 
the signal is continuously transmit-
ted from the ABS ECU to release 
the hydraulic state (when the bat-
tery voltage is normal).  Brake dragging
 Hydraulic unit operation test 2
 Front wheel brake line
Malfunction 
code 41
42 Rear wheel will not recover from 
the locking tendency even though 
the signal is continuously transmit-
ted from the ABS ECU to release 
the hydraulic state (when the bat-
tery voltage is normal).  Brake dragging
 Hydraulic unit operation test
 Rear wheel brake line
Malfunction 
code 42
51 Front wheel will not recover from 
the locking tendency even though 
the signal is continuously transmit-
ted from the ABS ECU to release 
the hydraulic state (when the bat-
tery voltage is low).  Brake dragging
 Hydraulic unit operation test 2
 Front wheel brake line
 Battery voltage
Malfunction 
code 51
52 Rear wheel will not recover from 
the locking tendency even though 
the signal is continuously transmit-
ted from the ABS ECU to release 
the hydraulic state (when the bat-
tery voltage is low).  Brake dragging
 Hydraulic unit operation test 2
 Rear wheel brake line
 Battery voltage
Malfunction 
code 52
61 (front) 62 (rear) Sensor power supply is low  Battery voltage low
 Battery terminal is disconnected Malfunction 
code 61 
(front) and 62 
(rear)
Malfunc-
tion code Problem Check point Reference 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-91
* Malfunction code 11 is indicated if the rear wheel rotates for more than 20 seconds with the front
wheel stopped.
NOTE:
Malfunction code 15 (front wheel sensor) or 16 (rear  wheel sensor) is displayed if a defective con-
nection to either the front or rear sensor is detected whether or not the vehicle is ridden.
Malfunction code 11 (Front wheel sensor signal is not received properly.)
Turn the main switch to “OFF”, then back to “ON” after removing the test coupler adapter.
1. ABS warning light remains on. → Defective connection in the front wheel sensor circuit.
 Front wheel sensor coupler is disconnected.  → [D-3]
 Front wheel sensor lead or internal circuit is broken.  → [D-3]
 Wire harness (ABS) sens or circuit is broken. → (Refer to CIRCUIT DIAGRAM on page 8-71.)
 ABS ECU coupler terminal is disconnected.  → [D-1]
2. ABS warning light goes on for 2 seconds then goes off. 1. With the front wheel stopped, the rear wheel was rotated for more than 20 seconds. This is  not a malfunction.
2. Signal is not generated at the front wheel sensor.  Front wheel sensor is not installed properly.  → [D-3]
 Front wheel sensor rotor is defective.  → [D-3]
3. Front wheel sensor circuit is short-circuited.  Front wheel sensor or lead is short-circuited.  → [D-3]
 Wire harness (ABS) sensor circuit is short-circuited.  → (Refer to CIRCUIT DIAGRAM on 
page 8-71.)
4. Front wheel sensor output drops.  Sensor signal output may drop due to failure on  bearings, wheel axle, wheel or sensor hous-
ing of front wheel. Check these components wh en installed for looseness, distortion, and 
bends.
Malfunction code 12 (Rear wheel sensor signal is not received properly.)
Turn the main switch to “OFF”, then back to “ON” after removing the test coupler adapter.
1. ABS warning light remains on. → Defective connection in the rear wheel sensor circuit.
 Rear wheel sensor coupler is disconnected.  → [D-4]
 Rear wheel sensor lead or internal circuit is broken.  → [D-4]
 Wire harness (ABS) sensor  circuit is disconnected. → (Refer to CIRCUIT DIAGRAM on page 
8-71.)
 ABS ECU coupler terminal is disconnected.  → [D-1]
63 (front)
64 (rear) Sensor power supply failure  Wire harness circuit
 Battery terminal is disconnected
 Replace the ABS ECU Malfunction 
code 63 
(front) and 64 
(rear)
Present 
malfunc-
tion (test  always 
indicates  12 V) ABS ECU may be malfunctioning 
ABS wire harness circuit (test 
coupler circuits)
 ABS ECU (Replace) Maintenance 
of the ABS 
ECU
[D-1]
Malfunc-
tion code Problem Check point Reference 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-92
2. ABS warning light goes on for 2 seconds then goes off.1. With the rear wheel stopped, the front wheel was rotated at a speed faster than 11 km/h. This 
is not a malfunction.
2. Signal is not generated at the rear wheel sensor.  Rear wheel sensor is not installed properly.  → [D-4]
 Rear wheel sensor rotor is defective.  → [D-4]
3. Rear wheel sensor circuit is short-circuited.  Rear sensor or lead  is short-circuited. → [D-4]
 Wire harness (ABS) sensor circuit is short-circuited.  → (Refer to CIRCUIT DIAGRAM on 
page 8-71.)
4. Rear wheel sensor output drops.
 Sensor signal output may drop due to failure of the bearing, wheel, or brake caliper bracket of the rear wheel. Check these components when in stalled for looseness, distortion, and bends.
NOTE:
If the vehicle is ridden on extremely uneven roads continuously, th e ABS warning light may flash and 
malfunction code 11 or 12 may be recorded depending on the condition.
Malfunction code 13 (front wheel) and malfunction code 14 (rear wheel) (Incorrect signal is
detected by the front (13) or rear (14) wheel sensor.)
1. The wheel sensors or sensor rotors are not properly installed.
1. Installation of the front or rear wheel sensor
 Check that the wheel sensor is properly installed in the housing.  → [D-3, 4]
 Check if there is looseness between the housing and the front wheel.  → [D-3, 4]
 Check if there is looseness rear brake caliper bracket and the rear wheel.  → [D-3, 4]
2. Installation of the front or rear wheel sensor rotor  Check that the sensor rotor is correctly pressed in the front wheel.  → [D-3, 4]
 Check that the sensor rotor is correctly install to the rear wheel.  → [D-3, 4]
 Check the rotor and inside the rotor housing for foreign materials.  → [D-3, 4]
2. Teeth surfaces of the sensor rotors are defective.  Check for flaws on the teeth surfaces of the front or rear wheel sensor rotors.
Also, check for any foreign materials.  → [D-3, 4]
3. Sensor output has dropped.  Sensor signal output may drop due to failure of the bearings, wheel axle, rear brake caliper 
bracket wheel or sensor housing of (front) t he front or rear wheel. Check these components 
when installed for looseness, distortion, and bends.
Malfunction code 15 (front wheel sensor) and malfunction code 16 (rear wheel sensor) (No
continuity in the front or rear wheel sensor circuits.)
Broken front or rear wheel sensor circuit is detected.
 Front or rear wheel sensor coupler is broken.  → [D-3, 4]
 Front or rear wheel sensor or lead is broken.  → [D-3, 4]
 Sub-wire harness (ABS) sensor circuit is broken.  → (Refer to CIRCUIT DIAGRAM on page 8-
71.)
 Sub-wire harness (ABS) is disconnecte d from the ABS ECU coupler terminal. → [D-1]
NOTE:
 Check that both the front and rear wheel  sensor couplers are connected securely.
 If the vehicle is ridden after malfunction code 15  (front wheel sensor) or 16 (rear wheel sensor) is 
displayed, the malfunction code will be overwritten  from 15 to 11 (front wheel sensor signal) or 
from 16 to 12 (rear wheel sensor signal).
1. Check the wheel sensor signal Measure the wheel sensor signal output voltage.
Refer to CHECKING THE WHEEL SENSOR on page 8-123. 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-93
2. Check the appearance.
3. Check the wire harness.1. Disconnection of the ABS ECU coupler terminal
2. Remove the ABS ECU coupler an d wheel sensor coupler and check the conductivity, short-
circuit to GND and short- circuit to SSR-VCC from the wire harness.
 Conductivity of the wire harness Check the conductivity between “A”–“B”, and “C”–“D”.
 GND short-circuit
Check the short-circuit to GND between “A”–“B”, and “C”–“D”.
 Short-circuit between the wire harnesses Check the short-circuit between “A”–“C”, and “B”–“D”.
4. When the items “1” to “4” are normal, replace the wheel sensor.
5. Replace the ABS ECU if the co ndition does not become normal ev en if the wheel sensor is 
replaced.
Malfunction code 18 (Missing serration of sensor rotor)
1. Missing serration of the rear sensor rotor.  Replace the rear sensor rotor.
Malfunction code 21 (Disconnection and short-circuit of hydraulic unit solenoid.)
1. Hydraulic unit solenoid coupler  Check if the hydraulic unit solenoid coupler te rminal is disconnected. (Refer to ABS CONNEC-
TOR LOCATION CHART on page 8-75.)
2. Hydraulic unit solenoid  Check the front and rear wheel solenoids for continuity  → [D-5]
 Check the insulation of all solenoid terminals and the negative battery terminal.  → [D-5]
3. Wire harness (ABS)  Check the hydraulic unit sol enoid circuits for continuity. (See the illustration below.)
1. ABS ECU
2. Front wheel sensor
3. Rear wheel sensor
4. Blue 5. Black
6. Yellow/White
7. White
8. Gray 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-94
*Continuity between: “A”–“B”, “A”–“C”, “D”–“G”\
, “E”–“F”
 Check the insulation of the hydraulic unit solenoid circuits and the negative battery terminal.
4. Battery
 Battery terminal is disconnected
Malfunction code 22 (Starter motor monitor malfunction)
1. Disconnection of the wire harnes s for the start system circuit
→  Check the conductivity of the wire harnes s and repair or replace the failure part.
2. Disconnection of the starter motor monitor
→ Check the conductivity of the wire harnes s and repair or replace the failure part.
*Continuity between: “A”–“B”
NOTE:
If you do not start the engine with the starter switch but repeat push-starting the engine excessively, 
this code may be input.
Malfunction code 24 (Step light failure [Brake system circuit has failure].)
1. Disconnection of the wire  harness for the brake circuit
→  Check the conductivity of the wire harnes s and repair or replace the failure part.
2. Disconnection of the stop lamp monitor → Check the conductivity of the wire harnes s and repair or replace the failure part.
1. ABS ECU
2. White
3. Red
4. Red 5. Front solenoid
6. Rear solenoid
7. Green
8. White/Blue
1. Starter relay
2. Blue/White
3. ABS ECU
1. Front brake light switch
2. Rear brake light switch
3. Green/Yellow
4. Yellow5. Yellow
6. Brake light
7. Yellow
8. ABS ECU 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-95
*Continuity between: “A”–“B”
Malfunction code 25 (At the beginning of running, there is no pulse from the front wheel sen-
sor.)
 Rear wheel was rotated with the vehicle on the stand.
 Rear wheel was wheel-spin.
 Wheel tried.
 Defective installation of the whee l speed sensor for the front wheel.
Malfunction code 28 (Other malfunctions [Malfunction of the memory in ABS ECU].)
1 Other malfunctions →  Replace the ABS ECU.
Malfunction code 31 (Disconnection is detected between the battery and the ABS ECU sys-
tem.)
NOTE:
Check following the steps in sequence.
1. ABS motor fuse blown  Replace the ABS motor fuse.
2. Coupler joint between the battery and ABS ECU.  Connect the coupler securely until a “click” sound is heard.
3. Disconnection of the wire harnes s between the battery and ABS ECU
 Check the conductivity of the wire harnes s and repair or replace the failure part.

*Continuity between: “A”–“B”
4. When the items 1 to 3 are normal, replace the ABS ECU.
Malfunction code 32 (Circuit malfunction of ABS ECU is detected. Upstream side of the sole-
noid relay.)
NOTE:
Check following the steps in sequence.
1. Short-circuit between the battery positive terminal and fail safe relay monitor terminal  Check the conductivity of the wire harnes s and repair or replace the failure part.
2. Short-circuit between the battery ignition terminal and fail safe relay monitor terminal  Check the conductivity of the wire harnes s and repair or replace the failure part.
1. Battery
2. Red/White
3. ABS motor fuse 4. Red/Yellow
5. ABS ECU 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-96
*Continuity between: “A”–“C”, “B”–“C”
3. When the items 1 to 2 are normal, replace the ABS ECU.
Malfunction code 33 (Defective operation of  the ABS motor is detected. [ABS motor stops
and will not rotate.])
NOTE:
Check following the steps in sequence.
1. ABS motor fuse  Check if the ABS motor fuse beside the battery is blown.
2. ABS motor relay  Check if the ABS motor relay operates correctly.  → [D-2] 
3. Wire harness  Remove the ABS motor relay and the ABS motor  fuse, and then check for continuity between the 
brown (Refer to ABS CONNECT OR LOCATION CHART on page 8-75 in ABS motor relay cou-
pler drawing.) terminal of the wire harness ( ABS) and the wire harness (ABS) end (terminal A 
shown in the illustration) of t he ABS motor fuse terminal beside the battery. (Refer to CIRCUIT 
DIAGRAM on page 8-71.)
 Check for continuity between the positive batte ry terminal and the battery end of the ABS motor 
fuse terminal (terminal B shown in the above illustration).
 Remove the ABS ECU and the ABS motor relay from  the wire harness (ABS), and then check for 
continuity between the white/black lead termi nals of ABS ECU coupler and the white/red lead 
terminals of ABS motor coupler.
Malfunction code 34 (Defective operation of th e ABS motor is detected. [ABS motor keeps
running and will not stop.])
Check the following:
1. ABS motor
1. Battery
2. Red
3. Main switch
4. Brown/White 5. ABS ECU
6. White
7. Red
8. To HU
A. Terminal A
B. Terminal B 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-97
 Check if the ABS motor coupler located under the fuel tank is connected properly.
 Check the ABS motor for continuity.  → [D-5]
2. Wire harness (ABS)  Remove the ABS motor coupler and check for c ontinuity between the black terminal of the ABS 
motor coupler of the wire harness (ABS) and the negative battery terminal.
 Remove the ABS ECU coupler and check for continuity between the red/white terminal of the  ABS ECU coupler and the red/white terminal of the ABS motor coupler.  → [D-1]
 Remove the ABS motor relay and check for continuity between the red/white terminal of the ABS 
motor coupler of the wire harness (ABS) and the positive battery terminal.
3. ABS motor relay  Check if the ABS motor relay operates correctly.  → [D-2]
Malfunction code 35 (Disconnection is detected between the ABS ECU and solenoid system.
Downstream side of the solenoid relay.)
1. Disconnected coupler between  the ABS ECU and HU solenoid
Connect the coupler securely until a “click” sound is heard.
2. Disconnection of the wire harness  between the ABS ECU and HU solenoid
Check the conductivity of the wire harnes s and repair or replace the failure part.
*Continuity between: “A”–“B”, “A”–“C”
3. Battery terminal is disconnected.
4. When the items 1 to 3 are normal, replace the ABS ECU
Malfunction code 41 (Front wheel will not reco ver from the locking tendency even though the
signal is continuously transmitted from the ABS ECU to release the hydraulic state [when the
battery voltage is normal].)
Check the following:
1. Rotation of the front wheel
 Check that there is no brake disc drag on the front wheel and make sure it rotates smoothly.
 Check the front wheel axle for loose bearings and bends, and the brake disc for distortion.
2. Brake master cylinder and brake caliper
 Check that the brake fluid pressure is correctly transmitted to the brake caliper when the brake  lever is operated and that the pressure decreases when the lever is released.
3. Brake fluid
 Visually check the brake fluid in the brake master cylinder reservoir and the fluid for water, for- eign materials, solidification and contamination.
 Check for air in the brake hose lines.
4. Brake hose lines  Check the brake hose lines for kinks and deterioration.
1. ABS ECU
2. White
3. Red 4. Red
5. Green
6. White/Blue