2008 INFINITI QX56 check engine

BR-24
< ON-VEHICLE REPAIR >
BRAKE TUBE AND HOSE
1. Check brake lines (tubes and hoses), and connections for fluid leaks, damage, twist, deformation, contact
with other parts, and loose connections. Replace any parts as necessary. Refer to BR-13, "
Hydraulic Cir-
cuit".
2. While depressing brake pedal under a force of 785 N (80 kg-f, 177 lb-f) with engine running for approxi- mately 5 seconds, check each part for fluid leaks.
Revision: March 2010 2008 QX56

BR-28
< ON-VEHICLE REPAIR >
VACUUM LINES
VACUUM LINES
Removal and InstallationINFOID:0000000004894512
REMOVAL
1. Remove engine room cover. Refer to EM-24, "Removal and Installation"
2. Disconnect vacuum hose from hose clip.
3. Release clamps and disconnect vacuum hose.
4. Remove check valve from brake booster.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
• Insert vacuum hose for at least 24 mm (0.94 in).
• Do not use lubricating oil during assembly.
1. Hose clip2. Clamp3. Vacuum hose
4. Check valve
LFIA0216E
SBR225B
Revision: March 2010 2008 QX56

INSPECTION AND ADJUSTMENTBRC-9
< BASIC INSPECTION > [VDC/TCS/ABS]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
>> GO TO 2
2.PERFORM THE NEUTRAL POSITION ADJUST MENT FOR THE STEERING ANGLE SENSOR
1. On the CONSULT-III screen, touch “WORK SUPP ORT” and “ST ANG SEN ADJUSTMENT” in order.
2. Touch “START”. CAUTION:
Do not touch steering wheel whil e adjusting steering angle sensor.
3. After approximately 10 seconds, touch “END”. NOTE:
After approximately 60 seconds, it ends automatically.
4. Turn ignition switch OFF, then turn it ON again. CAUTION:
Be sure to perform above operation.
>> GO TO 3
3.CHECK DATA MONITOR
1. Run vehicle with front wheels in straight-ahead position, then stop.
2. Select “DATA MONITOR”. Then make sure “STR ANGLE SIG” is within 0 ±2.5 °.
Is the steering angle within the specified range?
YES >> GO TO 4
NO >> Perform the neutral position adjustment fo r the steering angle sensor again, GO TO 1
4.ERASE THE SELF-DIAGNOSIS MEMORY
Erase the self-diagnosis memory of the ABS ac tuator and electric unit (control unit) and ECM.
• ABS actuator and electric unit (control unit): Refer to BRC-24, "
CONSULT-III Function (ABS)".
• ECM: Refer to EC-63, "
CONSULT-III Function (ENGINE)".
Are the memories erased?
YES >> Inspection End
NO >> Check the items indica ted by the self-diagnosis.
CALIBRATION OF DECEL G SENSOR
CALIBRATION OF DECEL G SENSOR : DescriptionINFOID:0000000001686237
Refer to the table below to determine if calibration of the decel G sensor is required.
×: Required –: Not required
CALIBRATION OF DECEL G SENSOR : Special Repair RequirementINFOID:0000000001686238
CALIBRATION OF DECEL G SENSOR
CAUTION:
To calibrate the decel G sensor, make sure to use CONSULT-III
Situation Calibration of decel G sensor
Removing/Insta lling ABS actuator and electr ic unit (control unit) —
Replacing ABS actuator and elec tric unit (control unit) ×
Removing/Installing steering angle sensor ×
Replacing steering angle sensor ×
Removing/Installing steering components ×
Replacing steering components ×
Removing/Installing suspension components ×
Replacing suspension components ×
Change tires to new ones —
Tire rotation —
Adjusting wheel alignment ×
Revision: March 2010 2008 QX56

BRC-10
< BASIC INSPECTION >[VDC/TCS/ABS]
INSPECTION AND ADJUSTMENT
(Calibration cannot be
done without CONSULT-III)
1.ALIGN THE VEHICLE STATUS
Stop vehicle with front wheels in straight-ahead position.
>> GO TO 2
2.PERFORM CALIBRATION OF DECEL G SENSOR
1. On the CONSULT-III screen, touch “WORK SUPPORT” and “DECEL G SEN CALIBRATION” in order.
2. Touch “START”.
3. After approximately 10 seconds, touch “END”. NOTE:
After approximately 60 seconds, it ends automatically.
4. Turn ignition switch OFF, then turn it ON again.
CAUTION:
Be sure to perform above operation.
>> GO TO 3
3.CHECK DATA MONITOR
1. Run vehicle with front wheels in straight-ahead position, then stop.
2. Select “DATA MONITOR”. Then make sure “DECEL G SEN” is within ± 0.08G.
Is the inspection result normal?
YES >> GO TO 4
NO >> Perform calibration of decel G sensor again, GO TO 1
4.ERASE THE SELF-DIAGNOSIS MEMORY
Erase the self-diagnosis memory of the ABS ac tuator and electric unit (control unit) and ECM.
• ABS actuator and electric unit (control unit): Refer to BRC-24, "
CONSULT-III Function (ABS)".
• ECM: Refer to EC-63, "
CONSULT-III Function (ENGINE)".
Are the memories erased?
YES >> Inspection End
NO >> Check the items indicated by the self-diagnosis.
Revision: March 2010 2008 QX56

BRC-28
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
*: ON for 1 to 2 seconds after the touch, and then OFF
ABS MOTOR• Touch “ON” and “OFF” on screen. Make sure motor relay and actuator relay operates as shown in table
below.
BOOSTER DRIVE
• Touch “UP” and “DOWN” on the screen. Check that booster drive operates as shown in table below.
CAUTION:
Perform active test subject to the conditions below.
• Do not operate brake pedal during active test.
• Make sure the engine revo lution is over 500 rpm.
• Make sure the vehicle is not moving.
RR RH SOL
RR RH ABS SOLE-
NOID (ACT) RR RH IN SOL
OFF ON ON OFF OFF OFF
RR RH OUT SOL OFF OFF ON* OFF OFF OFF
RR LH SOL
RR LH ABS SOLE-
NOID (ACT) RR LH IN SOL
OFF ON ON OFF OFF OFF
RR LH OUT SOL OFF OFF ON* OFF OFF OFF
REAR SOL RR RH IN SOL
OFF ON ON OFF OFF OFF
RR RH OUT SOL OFF OFF ON* OFF OFF OFF
RR LH IN SOL OFF ON ON OFF OFF OFF
RR LH OUT SOL OFF OFF ON* OFF OFF OFF
Operation ONOFF
MOTOR RELAY ONOFF
ACTUATOR RLY ONON
Operation UPDOWN
STOP LAMP SW ONOFF
BST OPER SIG ONOFF
PRESS SENSOR 50 ± 5 bar 0 bar
PRESS SEN 2 50 ± 5 bar 0 bar
STP OFF RLY OFFOFF
Operation
ABS solenoid valve
ABS solenoid valve (ACT)
UP KEEP DOWN UP ACTUA-
TOR UP ACTUA-
TOR KEEP
Revision: March 2010 2008 QX56

BRC-40
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1113, C1145, C1146 YAW
RATE/SIDE/DECEL G SENSOR
C1113, C1145, C1146 YAW RATE/SIDE/DECEL G SENSOR
DescriptionINFOID:0000000001686278
The yaw rate/side/decel G sensor detects the yaw rate /side/decel G affecting the vehicle, and transmits the
data to the ABS actuator and electric uni t (control unit) as an analog voltage signal.
DTC LogicINFOID:0000000001686279
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.CHECK SELF-DIAGNOSIS RESULTS
Check the self-diagnosis results.
Is above displayed on the self-diagnosis display?
YES >> Proceed to diagnosis procedure. Refer to BRC-40, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000001686280
CAUTION:
• Sudden turns (such as spin turns, acceleration turns), drifting, etc. when VDC function is OFF may
cause the yaw rate/side/decel G senso r system to indicate a malfunction. This is not a malfunction if
normal operation can be resumed after restarting the engine.
• If vehicle is on turn table at entrance to parkin g garage, or on other moving surface, VDC OFF indica-
tor lamp may illuminate and CONSULT-III self-dia gnosis may indicate yaw rate sensor system mal-
function. However, in this case there is no malfunction in yaw rate sensor system. Take vehicle off of
turn table or other moving surface, and st art engine. Results will return to normal.
INSPECTION PROCEDURE
1.CONNECTOR INSPECTION
Disconnect the ABS actuator and electric unit (control unit) connector E125 and yaw rate/side/decel G sensor
connector M108.
Check the terminals for deformation, disconnection, looseness or damage.
Is the inspection result normal?
YES >> GO TO 2
NO >> Repair or replace as necessary.
2.YAW RATE/SIDE/DECEL G SENSOR HARNESS INSPECTION
DTC Display item Malfunction detected condition Possible cause
C1113 G-SENSOR Longitudinal G-sensor is malfunctioning, or signal line of
longitudinal G-sensor is open or shorted.
• Harness or connector
• ABS actuator and electric unit
(control unit)
• Yaw rate/side/decel G sensor
C1145 YAW RATE SENSOR
Yaw rate sensor is malfunctioning, or the yaw rate sensor
signal line is open or shorted.
C1146 SIDE G-SEN CIRCUIT Side G sensor is malfunctioning, or circuit of side G sen-
sor is open or shorted.
Self-diagnosis results
G-SENSOR
YAW RATE SENSOR
SIDE G-SEN CIRCUIT
Revision: March 2010 2008 QX56

BRC-54
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
C1130, C1131, C1132, C
1133, C1136 ENGINE SIGNAL
C1130, C1131, C1132, C1133, C1136 ENGINE SIGNAL
DescriptionINFOID:0000000001686302
ABS actuator and electric unit (control unit) and ECM exchange the engine signal with CAN communication
line.
DTC LogicINFOID:0000000001686303
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.CHECK SELF-DIAGNOSIS RESULTS
Check the self-diagnosis results.
Is above displayed on the self-diagnosis display?
YES >> Proceed to diagnosis procedure. Refer to BRC-54, "Diagnosis Procedure".
NO >> Inspection End
Diagnosis ProcedureINFOID:0000000001686304
INSPECTION PROCEDURE
1.CHECK ENGINE SYSTEM
1. Perform ECM self-diagnosis. Repair or replace it ems indicated, then perform ECM self-diagnosis again.
Refer to EC-63, "
CONSULT-III Function (ENGINE)".
2. Perform ABS actuator and electric unit (control unit) self-diagnosis. Refer to BRC-24, "
CONSULT-III Func-
tion (ABS)".
Is any item indicated on the self-diagnosis display?
YES >> Repair or replace the affected part.
NO >> Inspection End
Special Repair RequirementINFOID:0000000001691153
1.ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION
Always perform neutral position adjustment for the st eering angle sensor when replacing the ABS actuator
and electric unit (control unit). Refer to BRC-8, "
ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL
POSITION : Description".
>> GO TO 2
DTC Display item Malfunction detected condition Possible cause
C1130 ENGINE SIGNAL 1
Based on the signal from ECM, ABS actuator and electric
unit (control unit) judges that engine fuel cut system is
malfunctioning. • Harness or connector
• ABS actuator and electric unit
(control unit)
•ECM
• CAN communication line
C1131 ENGINE SIGNAL 2
C1132 ENGINE SIGNAL 3
C1133 ENGINE SIGNAL 4
C1136 ENGINE SIGNAL 6
Self-diagnosis results
ENGINE SIGNAL 1
ENGINE SIGNAL 2
ENGINE SIGNAL 3
ENGINE SIGNAL 4
ENGINE SIGNAL 6
Revision: March 2010 2008 QX56

BRC-84
< COMPONENT DIAGNOSIS >[VDC/TCS/ABS]
BRAKE WARNING LAMP
BRAKE WARNING LAMP
DescriptionINFOID:0000000001686361
×
: ON –: OFF
NOTE:
• 1: Brake warning lamp will turn on in case of parking brake operation (when switch is ON) or of brake fluid level switch opera tion
(when brake fluid is insufficient).
• 2: After starting engine, brake warning lamp is turned off.
Component Function CheckINFOID:0000000001686362
1.BRAKE WARNING LAMP OPERATION CHECK
Check that the lamp illuminates for approximately 1 second after the ignition switch is turned ON.
Is the inspection result normal?
YES >> Inspection End
NO >> Go to diagnosis procedure. Refer to BRC-84, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001691169
1.CHECK SELF-DIAGNOSIS
Perform ABS actuator and electric unit (control unit) self-diagnosis. Refer to BRC-24, "
CONSULT-III Function
(ABS)".
Is the inspection result normal?
YES >> GO TO 2
NO >> Check items displayed by self-diagnosis.
2.CHECK COMBINATION METER
Check if the indication and operation of combination meter are normal. Refer to MWI-24, "
Diagnosis Descrip-
tion".
Is the inspection result normal?
YES >> Replace ABS actuator and electr ic unit (control unit). Refer to BRC-116, "Removal and Installa-
tion".
NO >> Replace combination meter. Refer to MWI-76, "
Removal and Installation".
Condition Brake warning lamp (Note 1)
Ignition switch OFF –
For 1 second after turning ON ignition switch × (Note 2)
1 second later after turning ON ignition switch × (Note 2)
EBD function is malfunctioning. ×
Revision: March 2010 2008 QX56