INFINITI QX56 2011 Factory Service Manual

BRC-94
< DTC/CIRCUIT DIAGNOSIS >[WITH VDC]
C1140 ACTUATOR RELAY SYSTEM
1. Turn the ignition switch OFF.
2. Check continuity between ABS actuator and electr
ic unit (control unit) harness connector and the ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK TERMINAL
Check ABS actuator and electric unit (control unit) pin terminals for damage or loose connection with harness
connector.
Is the inspection result normal?
YES >> Replace ABS actuator and electr ic unit (control unit). Refer to BRC-137, "Removal and Installa-
tion".
NO >> Repair or replace error-detected parts.
ABS actuator and electric unit (control unit) — Continuity
Connector Terminal
E36 2
Ground Existed
3
E37 48
Revision: 2010 May2011 QX56

C1142 PRESS SENSORBRC-95
< DTC/CIRCUIT DIAGNOSIS > [WITH VDC]
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C1142 PRESS SENSOR
DTC LogicINFOID:0000000006222617
DTC DETECTION LOGIC
*: Models with Advanced Driver Assistance System
DTC CONFIRMATION PROCEDURE
1.CHECK DTC DETECTION
With CONSULT-III.
1. Turn the ignition switch OFF to ON.
2. Perform self-diagnosis for “ABS”.
Is DTC
“C1142” detected?
YES >> Proceed to diagnosis procedure. Refer to BRC-95, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222618
1.CHECK STOP LAMP SWITCH SUSTEM
Check stop lamp switch system. Refer to BRC-79, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.CHECK BRAKE FLUID LEACKAGE
Check brake fluid leakage. Refer to BR-10, "
Inspection".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace error-detected parts.
3.CHECK BRAKE PIPING
Check brake piping. Refer to BR-24, "
FRONT : Inspection" (front), BR-26, "REAR : Inspection" (rear).
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace error-detected parts.
4.CHECK BRAKE PEDAL
Check brake pedal. Refer to BR-21, "
Inspection and Adjustment".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK HYDRAULIC BOOSTER ASSEMBLY
Check hydraulic booster assembly. Refer to BR-32, "
Inspection and Adjustment".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace error-detected parts.
6.CHECK FRONT DISC BRAKE
Check front disc brake. Refer to BR-39, "
BRAKE CALIPER ASSEMBLY : Inspection".
DTC Display Item Malfunction detected condition Possible causes
C1142 PRESS SEN CIRCUIT When a malfunction is detected in master cylinder
pressure sensor or control pressure sensor
*. Stop lamp switch system
 ABS actuator and electric unit
(control unit)
 Brake system
Revision: 2010 May2011 QX56

BRC-96
< DTC/CIRCUIT DIAGNOSIS >[WITH VDC]
C1142 PRESS SENSOR
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
7.CHECK REAR DISC BRAKE
Check rear disc brake. Refer to BR-45, "
BRAKE CALIPER ASSEMBLY : Inspection".
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair or replace error-detected parts.
8.CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
With CONSULT-III.
1. Erase Self-diagnosis result for “ABS”.
2. Start the engine and drive the vehicle for a short period of time.
3. Perform self-diagnosis for “ABS”.
Is DTC
“C1142” detected?
YES >> Replace ABS actuator and electr ic unit (control unit). Refer to BRC-137, "Removal and Installa-
tion"
NO >> Check ABS actuator and electric unit (control unit) harness connector and terminal for damage,
looseness and disconnection. Repair or replace error-detected parts.
Revision: 2010 May2011 QX56

C1143 STEERING ANGLE SENSORBRC-97
< DTC/CIRCUIT DIAGNOSIS > [WITH VDC]
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C1143 STEERING ANGLE SENSOR
DTC LogicINFOID:0000000006222619
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.CHECK DTC DETECTION
With CONSULT-III.
1. Turn the ignition switch OFF to ON.
2. Perform self-diagnosis for “ABS”.
Is DTC
“C1143” detected?
YES >> Proceed to diagnosis procedure. Refer to BRC-97, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222620
1.CHECK STEERING ANGLE SE NSOR MOUNTING CONDITION
Check steering angle sensor mounting condition. Refer to SR-14, "
Exploded View".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.CHECK STEERING ANGLE SENSOR POWER SUPPLY
1. Turn the ignition switch OFF.
2. Disconnect steering angle sensor harness connector.
3. Check voltage between steering angle sensor harness connector and ground.
4. Turn the ignition switch ON. CAUTION:
Never start engine.
5. Check voltage between steering angle sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK STEERING ANGLE SENSOR POWER SUPPLY CIRCUIT
1. Turn the ignition switch OFF.
2. Check 10A fuse (#7).
DTC Display Item Malfunction detected condition Possible causes
C1143 ST ANG SEN CIRCUIT When a malfunction is detected in steering angle sen-
sor.  Harness or connector
 Steering angle sensor
 ABS actuator and electric unit
(control unit)
Fuse
 Ignition power supply system
 CAN communication line
Steering angle sensor — Voltage
Connector Terminal
M30 4 Ground Approx. 0 V
Steering angle sensor — Voltage
Connector Terminal
M30 4 Ground Battery voltage
Revision: 2010 May2011 QX56

BRC-98
< DTC/CIRCUIT DIAGNOSIS >[WITH VDC]
C1143 STEERING ANGLE SENSOR
3. Disconnect fuse block (J/B) harness connector.
4. Check continuity between steering angle sensor
harness connector and fuse block (J/B) harness connec-
tor.
5. Check continuity between steering angle sensor harness connector and ground.
Is the inspection result normal?
YES >> Perform trouble diagnosis for ignition power supply. Refer to PG-89, "Wiring Diagram - IGNITION
POWER SUPPLY -".
NO >> Repair or replace error-detected parts.
4.CHECK STEERING ANGL E SENSOR GROUND CIRCUIT
1. Turn the ignition switch OFF.
2. Check continuity between steering angle sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK TERMINAL
 Check steering angle sensor pin terminals for damage or loose connection with harness connector.
 Check fuse block (J/B) pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace error-detected parts.
6.CHECK CAN COMMUNICATION LINE
Check “STRG BRANCH LINE CIRCUIT”. Refer to LAN-81, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> Replace ABS actuator and electr ic unit (control unit). Refer to BRC-137, "Removal and Installa-
tion".
NO >> Repair or replace error-detected parts. Refer to BRC-7, "
Precaution for Harness Repair".
Steering angle sensor Fuse block (J/B)
Continuity
Connector Terminal Connector Terminal
M30 4 M1 2A Existed
Steering angle sensor —Continuity
Connector Terminal
M30 4 Ground Not existed
Steering angle sensor —Continuity
Connector Terminal
M30 1 Ground Existed
Revision: 2010 May2011 QX56

C1144 INCOMPLETE STEERING ANGLE SENSOR ADJUSTMENT
BRC-99
< DTC/CIRCUIT DIAGNOSIS > [WITH VDC]
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C1144 INCOMPLETE STEERING AN GLE SENSOR ADJUSTMENT
DTC LogicINFOID:0000000006222621
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.CHECK DTC DETECTION
With CONSULT-III.
1. Turn the ignition switch OFF to ON.
2. Perform self-diagnosis for “ABS”.
Is DTC
“C1144” detected?
YES >> Proceed to diagnosis procedure. Refer to BRC-99, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222622
1.ADJUST THE NEUTRAL POSITION OF STEERING ANGLE SENSOR
Perform neutral position adjustment of steering angle sensor. Refer to BRC-64, "
Work Procedure".
>> GO TO 2.
2.CHECK ABS ACTUATOR AND ERECTRIC UNIT (CONTROL UNIT)
With CONSULT-III.
Perform self-diagnosis for “ABS”.
Is DTC
“C1144” detected?
YES >> GO TO 3.
NO >> INSPECTION END
3.CHECK STEERING ANGLE SENSOR SYSTEM
1. Turn the ignition switch OFF.
2. Check steering angle sensor system. Refer to BRC-97, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> Replace ABS actuator and electric unit (control unit). Refer to BRC-137, "Removal and Installa-
tion".
NO >> Repair or replace error-detected parts.
DTC Display Item Malfunction detected condition Possible causes
C1144 ST ANG SEN SIGNAL When neutral position adjustment of steering angle
sensor is not complete.  Harness or connector
 Steering angle sensor
 ABS actuator and electric unit
(control unit)
 Incomplete neutral position ad-
justment of steering angle sen-
sor
Revision: 2010 May2011 QX56

BRC-100
< DTC/CIRCUIT DIAGNOSIS >[WITH VDC]
C1145, C1146 YAW RATE/SIDE/DECEL G SENSOR
C1145, C1146 YAW RATE/SIDE/DECEL G SENSOR
DTC LogicINFOID:0000000006222623
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.CHECK DTC DETECTION
With CONSULT-III.
1. Turn the ignition switch OFF to ON.
2. Perform self-diagnosis for “ABS”.
Is DTC
“C1145” or “C1146” detected?
YES >> Proceed to diagnosis procedure. Refer to BRC-100, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222624
CAUTION:
 A malfunction in yaw rate/side/ decel G sensor system may be det ected when the vehicle sharply
turns during a spin turn, acceleratio n turn or drift driving while VDC function is OFF (VDC OFF indi-
cator lamp is in ON status). This is not a malfun ction if the status returns to normal after engine is
started again. In that case, erase self-diagn osis result memory using CONSULT-III.
 When the engine is in running stat us and the vehicle is on a turntable at the entrance of parking lot
or on a moving unit, VDC warning lamp may tu rn ON and “ABS” self-diagnosis may display “YAW
RATE SENSOR”. In this case, yaw rate sensor is not malfunctioning. The status returns to normal
when the vehicle is left from the turntable or movi ng unit and the engine is started again. In that
case, erase self-diagnosis result memory using CONSULT-III.
1.CHECK YAW RATE/SIDE/DECEL G SENSOR MOUNTING CONDITION
Check yaw rate/side/decel G sensor mounting condition. Refer to BRC-138, "
Exploded View".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.CHECK YAW RATE/SIDE/DECE L G SENSOR POWER SUPPLY
1. Turn the ignition switch OFF.
2. Disconnect yaw rate/side/decel G sensor harness connector.
3. Check voltage between yaw rate/side/dec el G sensor harness connector and ground.
4. Turn the ignition switch ON. CAUTION:
Never start engine.
5. Check voltage between yaw rate/side/dec el G sensor harness connector and ground.
DTC Display Item Malfunction detected condition Possible causes
C1145 YAW RATE SENSOR  When a malfunction is detected in yaw rate signal.
 When yaw rate signal is not continuously received
for 2 seconds or more.
 When side G signal is not continuously received for 2 seconds or more.
 When decel G signal is not continuously received for 2 seconds or more.  Harness or connector
 Yaw rate/side/decel G sensor
 ABS actuator and electric unit
(control unit)
 Ignition power supply system
Fuse
C1146 SIDE G-SEN CIRCUIT When a malfunction is detected in side/decel G sig-
nal.
Yaw rate/side/decel G sensor
—Voltage
Connector Terminal
M55 3 Ground Approx. 0 V
Revision: 2010 May2011 QX56

C1145, C1146 YAW RATE/SIDE/DECEL G SENSOR
BRC-101
< DTC/CIRCUIT DIAGNOSIS > [WITH VDC]
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Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK YAW RATE/SIDE/DECEL G SENSOR POWER SUPPLY CIRCUIT
1. Turn the ignition switch OFF.
2. Check 10A fuse (#57).
3. Disconnect IPDM E/R harness connector.
4. Check continuity between yaw rate/side/decel G sensor harness connector and IPDM E/R harness con-
nector.
5. Check continuity between yaw rate/side/decel G sensor harness connector and ground.
Is the inspection result normal?
YES >> Perform trouble diagnosis for ignition power supply. Refer to PG-89, "Wiring Diagram - IGNITION
POWER SUPPLY -".
NO >> Repair or replace error-detected parts.
4.CHECK YAW RATE/SIDE/DECEL G SENSOR GROUND CIRCUIT
1. Turn the ignition switch OFF.
2. Check continuity between yaw rate/side/decel G sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace error-detected parts.
5.CHECK COMMUNICATION LINE (1)
1. Disconnect ABS actuator and electric unit (control unit) harness connector.
2. Check continuity between yaw rate/side/decel G sensor harness connector and ABS actuator and electric
unit (control unit) harness connector.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace error-detected parts.
Yaw rate/side/decel G sensor —Voltage
Connector Terminal
M55 3 Ground Battery voltage
Yaw rate/side/decel G sensor IPDM E/R Continuity
Connector Terminal Connector Terminal
M55 3 E15 59 Existed
Yaw rate/side/decel G sensor —Continuity
Connector Terminal
M55 3 Ground Not existed
Yaw rate/side/decel G sensor —Continuity
Connector Terminal
M55 6 Ground Existed
Yaw rate/side/decel G sens or ABS actuator and electric unit (control unit)
Continuity
Connector Terminal Connector Terminal
M55 4
E36 9
Existed
510
Revision: 2010 May2011 QX56

BRC-102
< DTC/CIRCUIT DIAGNOSIS >[WITH VDC]
C1145, C1146 YAW RATE/SIDE/DECEL G SENSOR
6.CHECK COMMUNICATION LINE (2)
1. Connect ABS actuator and electric unit (control unit) harness connector.
2. Check resistance between yaw rate/side/decel G sensor harness connector terminals.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Replace ABS actuator and electric unit (control unit). Refer to BRC-137, "
Removal and Installa-
tion".
7.CHECK COMMUNICATION LINE (3)
1. Disconnect ABS actuator and electric unit (control unit) harness connector.
2. Check continuity between yaw rate/side/ decel G sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair or replace error-detected parts.
8.CHECK TERMINAL
 Check ABS actuator and electric unit (control unit) pin terminals for damage or loose connection with har-
ness connector.
 Check yaw rate/side/decel G sensor pin terminal s for damage or loose connection with harness connector.
 Check IPDM E/R pin terminals for damage or loose connection with harness connector.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Repair or replace error-detected parts.
9.REPLACE YAW RATE/SIDE/DECEL G SENSOR
With CONSULT-III.
1. Connect ABS actuator and electric unit (control unit) harness connector.
2. Connect IPDM E/R harness connector.
3. Replace yaw rate/side/decel G sensor. Refer to BRC-138, "
Removal and Installation".
4. Erase Self-diagnosis result for “ABS”.
5. Turn the ignition switch OFF.
6. Turn the ignition switch ON. CAUTION:
Never start engine.
7. Perform self-diagnosis for “ABS”.
Is DTC
“C1145” or “C1146” detected?
YES >> Replace ABS actuator and electr ic unit (control unit). Refer to BRC-137, "Removal and Installa-
tion".
NO >> INSPECTION END
Yaw rate/side/decel G sensor Resistance
Connector Terminal
M55 4
100 – 140 Ω
5
Yaw rate/side/decel G sensor Ground Continuity
Connector Terminal
M55 4
— Not existed
5
Revision: 2010 May2011 QX56

C1155 BRAKE FLUID LEVEL SWITCHBRC-103
< DTC/CIRCUIT DIAGNOSIS > [WITH VDC]
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C1155 BRAKE FLUID LEVEL SWITCH
DTC LogicINFOID:0000000006222625
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.CHECK DTC DETECTION
With CONSULT-III.
1. Turn the ignition switch OFF to ON, and then wait 1 minute or more.
2. Perform self-diagnosis for “ABS”.
Is DTC
“C1155” detected?
YES >> Proceed to diagnosis procedure. Refer to BRC-103, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222626
1.CHECK BRAKE FLUID LEVEL
1. Turn the ignition switch OFF.
2. Check brake fluid level. Refer to BR-10, "
Inspection".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Refill brake fluid. Refer to BR-11, "
Refilling".
2.CHECK BRAKE FLUID LEVEL SWITCH HARNESS
1. Disconnect brake fluid level switch harness connector.
2. Disconnect ABS actuator and electric unit (control unit) harness connector.
3. Check continuity between brake fluid level switch harness connector and ABS actuator and electric unit
(control unit) harness connector.
4. Check continuity between brake fluid level switch harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace error-detected parts.
3.CHECK BRAKE FLUID LEVEL SWITCH GROUND
Check continuity between brake fluid level switch harness connector and ground.
DTC Display Item Malfunction detected condition Possible causes
C1155 BR FLUID LEVEL LOW  When brake fluid level low signal is detected.
 When an open circuit is detected in brake fluid level
switch circuit.  Harness or connector
 ABS actuator and electric unit
(control unit)
 Brake fluid level switch
Brake fluid level switch ABS actuator and electric unit (control unit) Continuity
Connector Terminal Connector Terminal
E47 1 E36 13 Existed
Brake fluid level switch —Continuity
Connector Terminal
E47 1 Ground Not existed
Revision: 2010 May2011 QX56