Yamaha Fz6 N Service Manual

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-78
EAS27770
[D-1] MAINTENANCE OF THE ABS ECU
Removing the ABS ECU
1. Remove: ABS ECU “1”
NOTE:
When removing the ABS ECU, take care not to 
damage the ABS ECU or ABS ECU couplers.
2. Remove: ABS ECU coupler “1”
 ABS ECU coupler “2”
NOTE:
 Do not pull the ABS ECU leads to remove the ABS ECU couplers.
 Always press on the locks “3” to disconnect 
the ABS ECU couplers from the ABS ECU. Checking the ABS ECU
1. Check:
 Terminals “1” of the ABS ECU Cracks/damages  → Replace ABS ECU
 Terminals “2” of the ABS ECU coupler
Connection defective, contaminated, come-
off  → Correct or clean.
NOTE:
If the ABS ECU couplers are clogged with mud 
or dirt, clean with compressed air.
EAS27780
[D-2] MAINTENANCE OF THE ABS MOTOR 
RELAY
Removing the ABS motor relay
1. Remove:
 ABS motor relay coupler
NOTE:
Do not pull the ABS motor relay leads to 
remove the ABS motor relay coupler.
Always press on the lock to disconnect the 
ABS motor relay coupler from the ABS motor 
relay.
EAS27790
ABS TROUBLESHOOTING OUTLINE
This section describes the troubleshooting about ABS in details. Read carefully this service manual 
before repairing various malfunctions, understand and perform the service.
Electronic control unit (ECU) has the self diagnos tic function. When failures occur in the system, the 
ABS warning light on the meter as sembly indicates a malfunction.
Troubleshooting mentioned below describes the  cause pursuing and service method according to 
the indication by the multifunction display. For troub leshooting other than these items, perform by fol-
lowing the normal service method.
WARNING
EWA13880
When maintenance or checks have been performed on components related to the ABS, be 
sure to perform a final check before delivering the vehicle to the customer. 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
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(Refer to [D-6] FINAL CHECK on page 8-104.)
ABS warning light goes on and the ABS condition
1.When the ABS warning light keeps going on → It works as a normal brake.
 Detecting the malfunction by means of  the ABS self diagnostic function.
2.Light goes on and off at the time of starting  → ABS operation is normal.
 ABS warning light goes on for 2 seconds every time  the main switch is turned on and goes off 
afterward.
 ABS warning lights go on while t he starter switch is pushed.
3.When the ABS warning light flashes  → ABS operation is normal.
 Brake switch is defective or improperly adjusted.
 Rear wheel is racing.
 Continuous riding on extremely uneven roads.
 Other defective
Self diagnosis and services
The ABS ECU has a self diagnostic function. By util izing this function, quick and secure services are 
possible. Previously occurred error phenomenon can be  checked since it also installs the memory 
for storing malfunction history.
“In case malfunctions are detected”
It is disabled to call the malfunction code by  using the malfunction display since the ABS warning 
light already goes on. Connect t he test coupler adapter to the test connector, connect a pocket 
tester to the terminal of light green lead and check by its pointing needle movement.
Refer to [B-5] MALFUNCTION CHECK BY THE ABS SELF DIAGNOSIS (PRESENT MALFUNC-
TION) on page 8-85.
“In case any malfunctions are not detected”
The multifunction display indicates all the malf unction codes recorded in the ABS ECU. You can 
check it by using a pocket tester. Note everything if more than two items of malfunction codes are 
recorded.
“Deleting the malfunction code”
When the malfunction service is finished, check the normal operation of vehicle then delete the mal-
function code. By deleting the malfunction code memo ry, it is possible to pursue the cause correctly 
if the next defective phenomenon occurred.
Differences between the normal handling and services on a vehicle
 Care should be taken not to damage components by shocks and pulling too much since the ABS  components are precisely adjusted.
 ABS ECU, HU, Wheel sensors and ABS  motor relay cannot be disassembled.
 Malfunction history in ABS ECU is recorded. Delete  it when the service is finished. (This is 
because the past malfunction contents will be  redundantly displayed when the same malfunction 
occurred again.)
EAS27800
BASIC INSTRUCTION FOR TROUBLESHOOTING
WARNING
EWA14030
 Execute the troubleshooting on each malfunction from [A] to [D] in sequence.
 Use the sufficiently charged regular batteries only. Self diagnosis by ABS ECU
ABS ECU performs the static check for whole system 
when the main switch is turned on. It is also 
possible to check the malfunction while riding. It  is possible to check the recorded malfunction data 
by using a pocket tester or the multifunction disp lay of meter by setting the ABS ECU to the self 
diagnostic mode since all malfunctions  which has been once detected are recorded. 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-80
[A] Malfunction check by the ABS warning light
[B] Detail check of malfunction
Results by self diagnosis are displayed by the multifunction display or a pocket tester according to 
the ECU’s operation.
[C] Supposing the malfunction cause and position
Find the malfunction cause by reasoning th e place and situation where it occurred.
[D] ABS system services
Execute the final check after disassembly and assembly.
WARNING
EWA14040
Perform the troubleshooting [A]  → [B]  → [C]  → [D] in order. Be sure to follow the order since 
it results in the wrong diagnosis if the order is differently taken or omitted. 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
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EAS27810
BASIC PROCESS FOR TROUBLESHOOTING 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
8-82
NOTE:
Do not delete the malfunction code during the troubleshooting procedures. Be sure to delete it when 
the service is finished.
WARNING
EWA14050
Always execute the “final check” when the components related to ABS are checked and ser-
viced.
EAS27830
[A] ABS MALFUNCTION CHECK USING THE ABS WARNING LIGHT
Turn the main switch to “ON”. (Do not start the engine.)
1. The ABS warning light does not come on. [B-1]
2. The ABS warning light  remains on. [B-2]
3. The ABS warning light  flashes. [B-3]
4. The ABS warning light comes on for  2 seconds, then goes off. [B-4]
EAS4S81017
[B] DETAILED ABS MALFUNCTION CHECK
EAS4S81018
[B-1] THE ABS WARNING LIGHT DOES NOT COME ON
Do other indicators operate normally?
1. Yes [C-1]
2. No [C-2]
EAS4S81019
[B-2] THE ABS WARNING LIGHT REMAINS ON
NOTE:
Check following the steps in sequence.
1. Battery voltage low
Charge, inspect or replace the battery.
2. Malfunction codes displayed. Check the malfunction codes using the ABS test coupler adaptor. Perform troubleshooting corresponding  to the malfunction codes. [B-5]
3. Wire harness, ABS ECU and me ter coupler are disconnected.
Connect the coupler securely until a “click” sound is heard.
4. Check the disconnection between the ABS ECU and meter (ABS warning light). Check the conductivity of the wire harnes s and repair or replace the failure part.
5. Meter circuit malfunction Check by the following procedures.
1. Remove the ABS ECU and connect  the ABS test coupler adaptor.
2. Connect the white/red lead from the test coupler adaptor to the GND terminal and set the  main switch to “ON”.
3. Does the ABS warning light go off?
1. Yes  → Replace the ABS ECU.
2. No  → Replace the meter. 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
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EAS4S81020
[B-3] THE ABS WARNING LIGHT FLASHES
NOTE:
Check the battery voltage before proceeding.
Check the test coupler located in the left inner panel (front cowling). Is the T/C terminal ground?
1. Yes  → Disconnect the grounding lead from the T/C terminal and install the protective cap onto 
the test coupler.
NOTE:
When the test coupler adaptor is connected to  test coupler, the T/C terminal is grounded.
2. No  → [C-3]
Arrangement and the function of test couplers
 ECU becomes the malfunction diagnostic mode when the T/C terminal is grounded.
 Malfunction code which the ECU generated in the  malfunction diagnostic mode (rise and fall of 
voltage) is output at the T/F terminal.
 ABS warning light terminal  is used when checking the ABS warning light circuit.
 To ground the T/C terminal, connect the test coupler  adapter “A” with the test coupler. Before con-
necting, check if the battery is sufficiently charged.
EAS27860
[B-4] MALFUNCTION CHECK BY THE ABS SELF DIAGNOSIS (PAST MALFUNCTION)
Remove the side cowling (right) and check the location of test coupler “1”. Remove the protective 
cap and connect the ABS test coupler adapter “2” to the test coupler. The T/C terminal (sky-blue) is 
now connected to the ground.
1.Indicate the malfunction code (Example: malfunction code 11) 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
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2.ABS warning light flashes every 0.5 second for more than 6 seconds. → [C-4, C-5]
If the ABS warning light flashes every 0.5 second , the malfunction code of a past malfunction has 
not been stored in the memory of the ECU (ABS) . If a malfunction code is displayed on the multi-
function display, the ABS warning light flashes. Ma ke sure that the customer understands the pos-
sible conditions when the  ABS warning light comes on.
A. FZ6-N/FZ6-NA/FZ6-S/FZ6-SA
B. FZ6-NHG(W)/FZ6-NAHG/FZ6-SHG(W)/
FZ6-SAHG 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
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EAS27870
[B-5] MALFUNCTION CHECK BY THE ABS SELF DIAGNOSIS (PRESENT MALFUNCTION)
NOTE:
Before proceeding to read the part of “Arrangement and the function of test coupler”.
Remove the side cowling (right) and check the location of test coupler. Connect the test coupler 
adapter with the test coupler in order to ground the T/C terminal (sky-blue). (Figure-“A”)
Set the range of pocket tester to DC 20 V. Connect the negative (-) terminal of tester to the T/F ter-
minal (light green) and positive (+) terminal to the positive (+) terminal of battery. (Figure-“B”) Read 
the tester indication. (Figure-“C”)
NOTE:
Read the code through this means so that the “currently malfunction” code is not indicated on the 
meter.
1. ABS test coupler
2. Lock plate
3. Protective cap
4. Grounding
5. T/C terminal
6. T/F terminal 7. ABS warning light terminal (white/red)
8. Test coupler adapter
9. (light green)
10.(black)
11.(white/red) 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
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As an example, “10 digits/1 digit pattern” of tester reading is shown below.
EAS4S81021
[C] DETERMINING THE CAUSE AND LOCATION OF THE MALFUNCTION
EAS4S81022
[C-1] ONLY THE ABS WARNING LIGHT DOES NOT COME ON WHEN THE MAIN SWITCH IS 
SET TO “ON”
1. Confirmation using the test coupler adaptor
Connect the test coupler adapter to the test coupler.
NOTE:
Check following the steps in sequence.
1. Wire harness is short-circuited to GND between the ABS ECU and meter (ABS warning  light).
Check by the following procedures.
1. Remove the ABS ECU and  meter, and connect the ABS test coupler adaptor.
2. Check the conductivity between the white/red lead of test adaptor and GND.
3. If there is conductivity, the trouble is caus ed by the wire harness short-circuit. Repair or 
replace the failure part.
2. Meter circuit malfunction 1. Remove only the ABS ECU from the connector.
2. If the ABS warning light comes on when the main switch is turned “ON”, the meter is nor-
mal. It means the ABS ECU malfunction. Replace the ECU.
EAS4S81023
[C-2] ABS WARNING LIGHT AND ALL OTHER INDICATORS DO NOT COME ON
NOTE:
Check following the steps in sequence.
1. Check the power supply system.1. Check that the battery is connected correctly.
2. Check the battery voltage. (Refer to CHECKING AND CHARGING THE BATTERY on page  8-114.)
3. Check if the main fuse is blown. If the main fuse is blown, determine the cause and repair.
Replace with a new fuse. (Refer to CHECKING THE FUSES on page 8-113.)
2. Check the connections. 1. Check that the main fuse coupler is securely connected.
A. This example is the pattern which shows malfunction code 12.
B. This example is the pattern which shows  malfunction code 21. C. Time (second) 
						

							
ABS (ANTI-LOCK BRAKE SYSTEM)
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2. Check that the main switch coupler is securely connected.
3. Check that the meter assembly coupler is securely connected. (Refer to ABS CONNECTOR 
LOCATION CHART on page 8-75.)
When these checks are finished, re turn to [A] and check the ABS again.
EAS4S81024
[C-3] ABS WARNING LIGHT FLASHES
1. When the warning light flashes “ON” for 0.25  seconds and “OFF” for 0.75 seconds, check the 
stop switch or 3-4), 5).
2. When the warning light flashes “ON” for 0.75  seconds and “OFF” for 0.25 seconds, the starter 
motor monitor is defective. Same as the error code 22 or 3-1), 2), 3).
3. When the warning light flashes “ON” for 1 sec ond and “OFF” for 1 second, it is another malfunc-
tion. Same as the error code 28.
The following are probab le causes to explain why the ABS wa rning light flashed while riding and 
then stopped flashing or stopped flashing when main switch was set “OFF” to “ON”.
1. The rear wheel was rotated with the vehicle on the centerstand.  → The system is normal.
2. The rear wheel was raced.  → The system is normal.
3. The vehicle was ridden on the rear wheel with the front wheel elevated.  → The system is nor-
mal.
4. The vehicle was ridden on extremely uneven roads continuously.  → The system is normal.
5. The brake switch is defective or improperly adjusted.  → Replace or adjust.
EAS4S81025
[C-4] ABS WARNING LIGHT FLASHES EVERY 0.5 SECOND
If the ABS warning light flashes every 0.5 second, the malfunction code of a past malfunction has 
not been stored in the memory of the ABS ECU. If a malfunction code is displayed on the multifunc-
tion display, the ABS warning light flashes. Make sure that the customer understands the possible 
conditions when the ABS warning light comes on.
1. Voltage drop
For the ABS to operate correctly, the voltage s hould be always higher than the specified voltage. 
If the voltage drops to lower than 10 V, t he ABS warning light comes on and the ABS does not 
operate. When the voltage recovers to higher than 10 V, the ABS operates. However, the mag-
neto, battery and rectifier/regulator must be checked. Follow the regular procedures for service 
of the power supply system.
2. ABS is stopped by the ABS ECU The ABS ECU may stop the ABS operation if it is  exposed to extremely strong electromagnetic 
waves or static electricity.
When the ABS ECU is no longer exposed to the electr omagnetic waves, static electricity, and the 
ABS warning light is not flashing, there is no effe ct on the operation of the ABS. Explain to the 
customer that the ABS will operate normally.
EAS27880
[C-5] DIAGNOSIS BY THE MALFUNCTION CODE
Malfunction codes are used to determine the malfunct ions that have occurred. (Refer to “[B-4] MAL-
FUNCTION CHECK BY THE ABS SELF-DIAGNOSIS (PAST MALFUNCTION)” and “[B-5] MAL-
FUNCTION CHECK BY THE ABS SELF-DIAGNOSIS (PRESENT MALFUNCTION)”.) The 
malfunction codes are explained in the following table.
NOTE:
Record all of the malfunction codes displayed and check the check points.