2010 INFINITI QX56 ECU

FRONT DISC BRAKEBR-33
< ON-VEHICLE REPAIR >
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3. Install brake hose to brake caliper assembly using new copper washers. Align the brake hose to the projection as shown and
tighten union bolts to the specified torque.
CAUTION:
• Do not reuse copper washers.
• Securely attach brake hose to projection on cylinderbody.
4. Refill with new brake fluid and bleed air. Refer to BR-17, "
Bleeding Brake System".
5. Check front disc brake for drag and correct as necessary.
6. Install front wheel and tire. Refer to WT-49, "
Rotation".
SFIA2431E
Revision: April 20092010 QX56

REAR DISC BRAKEBR-35
< ON-VEHICLE REPAIR >
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2. Apply Molykote M-77 grease to knuckle slide where brake pad contacts and to the outer multi-layered
shim, pad retainers and inner shim.
CAUTION:
Do not get grease on the brake pads or brake rotor friction surfaces.
3. Install pads, shims, cover and retainers to cylinder body.
4. Apply rubber grease to the sliding sleeves and install cylinder body, sliding sleeves and sliding pin bolts and tighten to specification. Refer to BR-35, "
Exploded View of Brake Caliper".
5. Check rear disc brake for drag.
6. Install rear wheel and tires. Refer to WT-49, "
Rotation".
Brake Burnishing ProcedureINFOID:0000000005147919
Burnish contact surfaces between disc rotors and pads according to following procedure after refinishing or
replacing rotors, after replacing pads, or if a soft pedal occurs at very low mileage.
CAUTION:
• Be careful of vehicle speed because the brake does not operate easily until pad and disc rotor are securely seated.
• Only perform this procedure under safe road and traffic conditions. Use extreme caution.
1. Drive vehicle on straight, flat road.
2. Depress brake pedal with the power to stop vehicle within 3 to 5 seconds until the vehicle stops.
3. Drive without depressing brake for a few minutes to cool the brake.
4. Repeat steps 1 through 3 until pad and disc rotor are securely seated.
Exploded View of Brake CaliperINFOID:0000000005147920
1. Union bolt 2. Brake hose 3. Copper washer
4. Cap 5. Bleed valve 6. Sliding pin bolt
7. Cylinder body 8. Piston seal 9. Piston
10. Piston boot 11. Knuckle slide 12. Sliding sleeve boot
AWFIA0423GB
Revision: April 20092010 QX56

BR-36
< ON-VEHICLE REPAIR >
REAR DISC BRAKE
Removal and Installation of Brake Caliper and Disc Rotor
INFOID:0000000005147921
WARNING:
Clean dust on caliper and brake pad with a vacuum dust collector to minimize the hazard of air borne
particles or other materials.
CAUTION:
• While removing cylinder body, do not depress brake pedal because piston will pop out.
• Do not damage piston boot.
• Keep rotor free from brake fluid.
• Refill with new specified brake fluid.
• Burnish brake contact surface after refinishing or re placing rotors, after replacing pads, or it a soft
pedal occurs at very low mileage. Refer to BR-35, "
Brake Burnishing Procedure".
REMOVAL
1. Remove rear wheel and tire using power tool.
2. Fasten disc rotor using wheel nut.
3. Remove brake reservoir cap.
4. Remove union bolt and cylinder body bolts, then remove cylin-
der body.
NOTE:
Discard the copper washers, do not reuse.
5. Apply matching marks to disc rotor and wheel hub assembly if the disc rotor is to be reused, then remove disc rotor.
CAUTION:
Put matching marks on wheel hub assembly and disc rotor
if the disc rotor is to be reused.
INSTALLATION
1. If reusing the disc rotor, use the matching marks to align disc rotor on the wheel hub assembly, then install
disc rotor using a wheel nut to hold it in place.
CAUTION:
Use matching marks on wheel hub assembly and di sc rotor if the disc rotor is to be reused.
2. Install cylinder body and tighten cylinder body bolts to specification. CAUTION:
Before installing cylinder body to the vehic le, wipe off mating surface of cylinder body.
3. Install brake hose to cylinder body with new copper washers and tighten union bolt to specification.
CAUTION:
• Do not reuse copper washers.
• Securely attach brake hose to projection on cylinderbody.
4. Refill with new brake fluid and bleed. Refer to BR-17, "
Bleeding
Brake System".
5. Check rear disc brake for drag and correct as necessary.
6. Install rear wheel and tire. Refer to WT-49, "
Rotation".
13. Sliding sleeveB. Brake fluid R. Rubber grease
M. Molykote M-77 Front
LFIA0211E
SFIA1137E
Revision: April 20092010 QX56

FRONT DISC BRAKEBR-41
< DISASSEMBLY AND ASSEMBLY >
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3. Apply Molykote M-77 grease to piston boots. Cover the piston ends with piston boots, and then install cylinder side lip on piston
boots securely into the grooves on cylinder body.
CAUTION:
Do not reuse piston boots.
4. Apply clean brake fluid to pistons, then install pistons into cylin- der body and insert piston boot side lip into groove of pistons as
shown.
CAUTION:
Press the pistons evenly to prevent damage to cylinder
wall.
5. Apply rubber grease and insert into cylinder body by hand and insert piston bo\
ot piston-side lip into piston groove.
CAUTION:
Press pistons evenly and vary the pr essing point to prevent cylinder inner wall from being rubbed.
6. Apply rubber grease and install sliding pins, bushing and sliding pin boots to torque member.
7. Install the pads, shims, shim cover, and pad retainers from the torque member.
8. Install cylinder body. Tighten sliding pin bolts to the specified torque.
SFIA2432E
WFIA0211E
Revision: April 20092010 QX56

BRC-3
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C1185 ICC UNIT .................................................77
Description .......................................................... ....77
DTC Logic ...............................................................77
Diagnosis Procedure ...............................................77
Special Repair Requirement ...................................78
U1000 CAN COMM CIRCUIT .............................79
Description .......................................................... ....79
DTC Logic ...............................................................79
Diagnosis Procedure ...............................................79
VDC OFF SWITCH .............................................80
Description .......................................................... ....80
Component Function Check ....................................80
Diagnosis Procedure ...............................................80
Component Inspection ............................................81
Special Repair Requirement ...................................81
ABS WARNING LAMP ................................... ....82
Description .......................................................... ....82
Component Function Check ....................................82
Diagnosis Procedure ...............................................82
Special Repair Requirement ...................................82
BRAKE WARNING LAMP ............................. ....83
Description .......................................................... ....83
Component Function Check ....................................83
Diagnosis Procedure ...............................................83
Special Repair Requirement ...................................83
VDC OFF INDICATOR LAMP ........................ ....84
Description .......................................................... ....84
Component Function Check ....................................84
Diagnosis Procedure ...............................................84
Special Repair Requirement ...................................85
SLIP INDICATOR LAMP ................................ ....86
Description .......................................................... ....86
Component Function Check ....................................86
Diagnosis Procedure ...............................................86
Special Repair Requirement ...................................86
ECU DIAGNOSIS ........... ..............................87
ABS ACTUATOR AND ELECTRIC UNIT
(CONTROL UNIT) .......................................... ....
87
Reference Value ................................................. ....87
Wiring Diagram - BRAKE CONTROL SYSTEM - ....92
Fail-Safe ..................................................................99
DTC No. Index ......................................................100
SYMPTOM DIAGNOSIS ............................102
VDC/TCS/ABS ................................................ ..102
Symptom Table ................................................... ..102
EXCESSIVE ABS FUNCTION OPERATION
FREQUENCY ...................................................
103
Diagnosis Procedure ........................................... ..103
UNEXPECTED PEDAL REACTION ...............104
Diagnosis Procedure .............................................104
THE BRAKING DISTANCE IS LONG .............105
Diagnosis Procedure .............................................105
ABS FUNCTION DOES NOT OPERATE .......106
Diagnosis Procedure .............................................106
PEDAL VIBRATION OR ABS OPERATION
SOUND OCCURS ...........................................
107
Diagnosis Procedure ........................................... ..107
VEHICLE JERKS DURING VDC/TCS/ABS
CONTROL .......................................................
108
Diagnosis Procedure .............................................108
NORMAL OPERATING CONDITION .............109
Description .............................................................109
PRECAUTION ............................................110
PRECAUTIONS ...............................................110
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ..
110
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect .................................
110
Precaution for Brake System .................................111
Precaution for Brake Control .................................111
Precaution for CAN System ...................................112
PREPARATION .........................................113
PREPARATION ...............................................113
Special Service Tool ............................................ ..113
Commercial Service Tool ......................................113
REMOVAL AND INSTALLATION .............114
WHEEL SENSORS .........................................114
Removal and Installation ..................................... ..114
SENSOR ROTOR ............................................115
Removal and Installation .......................................115
ACTUATOR AND ELECTRIC UNIT (ASSEM-
BLY) ................................................................
116
Removal and Installation .......................................116
STEERING ANGLE SENSOR .........................118
Removal and Installation .......................................118
G SENSOR ......................................................119
Removal and Installation .......................................119
Revision: April 20092010 QX56

DIAGNOSIS SYSTEM [ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
BRC-23
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
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DIAGNOSIS SYSTEM [ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
CONSULT-III Function (ABS)INFOID:0000000005147962
FUNCTION
CONSULT-III can display each diagnostic item using the diagnostic test modes shown following.
SELF DIAGNOSTIC RESULT MODE
Operation Procedure
1. Before performing the self-diagnosis, start engine and drive vehicle at 30 km/h (19 MPH) or more for
approximately 1 minute.
How to Erase Self-diagnosis Results
1. After erasing DTC memory, start engine and drive vehicle at 30 km/h (19 MPH) or more for approximately 1 minute as the final inspection, and make sure t hat the ABS warning lamp, VDC OFF indicator lamp,
SLIP indicator lamp and brake warning lamp turn OFF.
CAUTION:
If memory cannot be erased, perform applicable diagnosis.
NOTE:
• When the wheel sensor malfunctions, after inspecting the wheel sensor system, the ABS warning lamp,
VDC OFF indicator lamp, SLIP indicator lamp and brake warning lamp will not turn OFF even when the
system is normal unless the vehicle is driving at approximately 30 km/h (19 MPH) or more for approxi-
mately 1 minute.
• Brake warning lamp will turn ON in case of parking brake operation (when switch is ON) or of brake fluid level switch operation (when brake fluid is insufficient).
• VDC OFF switch should not stay “ON” position.
Display Item List
Refer to BRC-100, "DTC No. Index".
DATA MONITOR MODE
Display Item List
Diagnostic test mode Function
Work support This mode enables a technician to adjust some devices faster and more accurately by following
the indications on CONSULT-III.
Data Monitor Input/Output data in the ABS actuator and electric uni t (control unit) can be read.
Active Test Diagnostic test mode is which CONSULT-III driv
es some actuators apart from the ABS actuator
and electric unit (control unit) and also shifts some parameters in a specified range.
Self Diagnostic Result Self-diagnostic results can be read and erased quickly.
CAN diag support monitor The results of transmit/receive diagnosis of CAN communication can be read.
ECU Identification ABS actuator and electric unit (control unit) part number can be read.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
FR LH SENSOR
(km/h, mph) ×× × Wheel speed (km/h, mph) calculated by front LH
wheel sensor signal is displayed.
FR RH SENSOR
(km/h, mph) ×× ×
Wheel speed (km/h, mph) calculated by front RH
wheel sensor signal is displayed.
RR LH SENSOR
(km/h, mph) ×× × Wheel speed (km/h, mph) calculated by rear LH
wheel sensor signal is displayed.
RR RH SENSOR
(km/h, mph) ×× × Wheel speed (km/h, mph) calculated by rear RH
wheel sensor signal is displayed.
Revision: April 20092010 QX56

BRC-24
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
DECEL G-SEN
(G) ×× × Longitudinal acceleration (G) detected by decel G-
sensor is displayed.
FR RH IN SOL
(On/Off) –
×× Front RH IN ABS solenoid (On/Off) status is dis-
played.
FR RH OUT SOL
(On/Off) –
×× Front RH OUT ABS solenoid (On/Off) status is dis-
played.
FR LH IN SOL
(On/Off) –
×× Front LH IN ABS solenoid (On/Off) status is displayed.
FR LH OUT SOL
(On/Off) –
×× Front LH OUT ABS solenoid (On/Off) status is dis-
played.
RR RH IN SOL
(On/Off) –
×× Rear RH IN ABS solenoid (On/ Off) status is displayed.
RR RH OUT SOL
(On/Off) –
×× Rear RH OUT ABS solenoid (On/Off) status is dis-
played.
RR LH IN SOL
(On/Off) –
×× Rear LH IN ABS solenoid (On/ Off) status is displayed.
RR LH OUT SOL
(On/Off) –
×× Rear LH OUT ABS solenoid (On/Off) status is dis-
played.
EBD WARN LAMP
(On/Off) ––
×Brake warning lamp (On/Off) status is displayed.
STOP LAMP SW
(On/Off) ×× ×
Stop lamp switch (On/Off) status is displayed.
MOTOR RELAY
(On/Off) –
×× ABS motor relay signal (On/Of f) status is displayed.
ACTUATOR RLY
(On/Off) –
×× ABS actuator relay signal (On/ Off) status is displayed.
ABS WARN LAMP
(On/Off) –
×× ABS warning lamp (On/Off) status is displayed.
OFF LAMP
(On/Off) –
×× VDC OFF Lamp (On/Off) status is displayed.
OFF SW
(On/Off) ×× ×
VDC OFF switch (On/Off) status is displayed.
SLIP LAMP
(On/Off) –
×× SLIP indicator lamp (On/Off) status is displayed.
BATTERY VOLT
(V) ×× ×
Voltage (V) supplied to ABS actuator and electric unit
(control unit) is displayed.
GEAR
(1 , 2

, 3, 4, 5) ×× × Gear position (1, 2, 3, 4, 5) judged by transmission
range switch signal is displayed.
SLCT LVR POSI
(P, N, D) ×× × Shift position (P, N, D) judged by transmission range
switch signal.
ENGINE SPEED
(rpm) ×× ×
Engine speed (rpm) judged by CAN communication
signal is displayed.
YAW R AT E S E N
(d/s) ×× × Yaw rate (d/s) detected by yaw rate sensor is dis-
played.
R POSI SIG
(On/Off) ––
×Reverse shift position (On/Off) judged by PNP switch
signal.
4WD FAIL REQ
(On/Off) ––
×Transfer control unit fail-safe mode (On/Off) is dis-
played.
N POSI SIG
(On/Off) ––
×Shift position judged by transmission range switch
signal.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
Revision: April 20092010 QX56

DIAGNOSIS SYSTEM [ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
BRC-25
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
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P POSI SIG
(On/Off) ––
×Shift position judged by transmission range switch
signal.
CV1
(On/Off) ––
×Front side switch-over solenoid valve (cut valve) (On/
Off) status is displayed.
CV2
(On/Off) ––
×Rear side switch-over solenoid valve (cut-valve) (On/
Off) status is displayed.
SV1
(On/Off) ––
×Front side switch-over solenoid valve (suction valve)
(On/Off) status is displayed.
SV2
(On/Off) ––
×Rear side switch-over solenoid valve (suction valve)
(On/Off) status is displayed.
2WD/4WD
(2WD/4WD) ––
×It recognizes on software whether it is 2WD and
whether it is in 4WD state.
ACCEL POS SIG
(%) ×
– ×Throttle valve open/close status judged by CAN com-
munication signal is displayed.
SIDE G-SENSOR
(m/s
2) ×
– ×Transverse acceleration detected by side G-sensor is
displayed.
STR ANGLE SIG
(deg) ×
– ×Steering angle detected by steering angle sensor is
displayed.
BST OPER SIG
(On/Off) ––
×Active booster operation (On/Off) status is displayed.
PRESS SENSOR
(bar) ×
– ×Brake pressure detected by pressure sensor is dis-
played.
EBD SIGNAL
(On/Off) ––
×EBD operation (On/Off) status is displayed.
ABS SIGNAL
(On/Off) ––
×ABS operation (On/Off) status is displayed.
TCS SIGNAL
(On/Off) ––
×TCS operation (On/Off) status is displayed.
VDC SIGNAL
(On/Off) ––
×VDC operation (On/Off) status is displayed.
EBD FAIL SIG
(On/Off) ––
×EBD fail signal (On/Off) status is displayed.
ABS FAIL SIG
(On/Off) ––
×ABS fail signal (On/Off) status is displayed.
TCS FAIL SIG
(On/Off) ––
×TCS fail signal (On/Off) status is displayed.
VDC FAIL SIG
(On/Off) ––
×VDC fail signal (On/Off) status is displayed.
CRANKING SIG
(On/Off) ––
×The input state of the key SW START position signal
is displayed.
FLUID LEV SW
(On/Off) ×
– ×Brake fluid level switch (On/Off) status is displayed.
PRESS SEN2
(bar) ––
×Brake pressure detected by pressure sensor is dis-
played.
DELTA S SEN
(mm) ––
×The amount of stroke sensor movements in the active
booster detected by DELTA S SEN is displayed.
RELEASE SW NO
(On/Off) ––
×Release switch signal (On/Off) status is displayed.
“On” indicates that the brake pedal is depressed. “Off”
indicates that the brake pedal is released.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAI
N
SIGNALS SELECT
ION
FROM MENU
Revision: April 20092010 QX56