steering INFINITI QX56 2011 Factory Service Manual

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

STEERING ANGLE SENSORBRC-139
< REMOVAL AND INSTALLATION > [WITH VDC]
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STEERING ANGLE SENSOR
Removal and InstallationINFOID:0000000006222679
REMOVAL
1. Remove spiral cable assembly. Refer to SR-14, "Removal and Installation".
2. Remove steering angle sensor.
INSTALLATION
Note the following, and install in the reverse order of removal.
 Perform steering angle sensor neutral position adjustm ent when steering angle sensor is removing/installing
or replaced. Refer to BRC-64, "
Work Procedure".
Revision: 2010 May2011 QX56

BRC-142
< SYSTEM DESCRIPTION >[BRAKE ASSIST (WITH PREVIEW FUNCTION)]
COMPONENT PARTS
SYSTEM DESCRIPTION
COMPONENT PARTS
Component Parts LocationINFOID:0000000006248456
1. ICC steering switch 2. Information display, ICC system
warning lamp, IBA OFF indicator
lamp, buzzer
(On the combination meter)3. BCM
Refer to BCS-4, "
BODY CONTROL
SYSTEM : Component Parts Loca-
tion"
4. Transfer control unit
Refer to DLN-10, "
Component Parts
Location"
5. ICC brake hold relay 6. ECM
Refer to EC-16, "
Component Parts
Location"
7. ICC sensor 8. TCM
Refer to TM-10, "
A/T CONTROL
SYSTEM : Component Parts Loca-
tion"
9. ABS actuator and el ectric unit (con-
trol unit)
Refer to BRC-10, "
Component Parts
Location"
10. Stop lamp switch 11. ICC brake switch 12. IBA OFF switch
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Revision: 2010 May2011 QX56

COMPONENT PARTSBRC-143
< SYSTEM DESCRIPTION > [BRAKE ASSIST (WITH PREVIEW FUNCTION)]
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Component DescriptionINFOID:0000000006248457
× : Applicable
13. Steering angle sensor
Refer to BRC-10, "
Component Parts
Location"
14. ADAS control unit
Refer to DAS-13, "
Component Parts
Location"
A. Back side of engine room (RH) B. Front bumper (center) C. Upper side of brake pedal
D. Under side of instrument lower driver
panel
Component Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
ADAS control unit ×××× ADAS control unit calculates a target distance between vehicles
and a target speed, based on signals received from each sensor
and switch to transmit an engine torque command value to ECM
and a brake fluid pressure cont rol signal to ABS actuator and
electric unit (control unit) via CAN communication
 ADAS control unit transmits buzzer output signal to combination
meter via CAN communication
ICC sensor ×××× ICC sensor detects light reflected from a vehicle ahead by irra-
diating laser forward and calculates a distance from the vehicle
ahead and a relative speed, based on the detected signal
 ICC sensor transmits the presence/absence of vehicle ahead and the distance from the vehicle to ADAS control unit via ITS
communication
ECM ×××× ECM transmits the accelerator pedal position signal, ICC brake
switch signal, stop lamp switch signal, ICC steering switch sig-
nal, etc. to ADAS control unit via CAN communication
 ECM controls the electric throttle control actuator based on the engine torque demand received from the ADAS control unit via
CAN communication
ABS actuator and electric unit
(control unit) ×××× ABS actuator and electric unit (c
ontrol unit) transmits the vehicle
speed signal (wheel speed), stop lamp signal and VDC/TCS/
ABS system operation condition to ADAS control unit via CAN
communication
 ABS actuator and electric unit (c ontrol unit) controls the brake,
based on a brake fluid pressure control signal received from the
ADAS control unit via CAN communication
BCM ×BCM transmits the front wiper request signal to ADAS control unit
via CAN communication
TCM ××TCM transmits the signal related to A/T control to ADAS control
unit via CAN communication
Revision: 2010 May2011 QX56

BRC-144
< SYSTEM DESCRIPTION >[BRAKE ASSIST (WITH PREVIEW FUNCTION)]
COMPONENT PARTS
NOTE:
Only IBA system uses
Combination meter
××××Performs the following operations using the signals received from
the ADAS control unit via the CAN communication
 Displays the ICC system operation status using the meter dis-
play signal
 Illuminates the ICC system warning lamp using the ICC warning
lamp signal
 Illuminates the IBA OFF indicator lamp using the IBA OFF indi- cator lamp signal
 Operates the buzzer (ICC warning chime) using the buzzer out- put signal
ICC steering switch ×× ICC steering switch allows the ON/OFF of the Intelligent Cruise
Control and the settings of a vehicle speed and distance be-
tween vehicles
 ICC steering switch signal is transmitted to ECM. ECM transmits the signal to the ADAS control unit via CAN communication
ICC brake switch ×××× ICC brake switch is turned OFF and stop lamp switch is turned
ON, when depressing the brake pedal
 ICC brake switch signal is input to ECM. These signals are transmitted from ECM to ADAS control unit via CAN communi-
cation
 Stop lamp switch signal is input to ECM and ABS actuator and electric unit (control unit). These signals are transmitted from
ECM and ABS actuator and electric unit (control unit) to ADAS
control unit via CAN communication
St op la mp sw i tc h
××××
ICC brake hold relay ××ICC brake hold relay activates the stop lamp by ICC brake hold re-
lay drive signal (stop lamp drive signal) outputted by the ADAS
control unit
Transfer control unit ××××Transfer control unit transmits a mode selection state of 4WD shift
switch to the ADAS control unit via CAN communication
IBA OFF switch ×
NoteIBA OFF switch signal is input to the ADAS control unit
Steering angle sensor ×Measures the rotation amount, rotation speed, and rotation direc-
tion of steering wheel, and then transmits them to ADAS control
unit via CAN communication
Component
Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
Revision: 2010 May2011 QX56

COMPONENT PARTSBRC-149
< SYSTEM DESCRIPTION > [INTELLIGENT BRAKE ASSIST]
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SYSTEM DESCRIPTION
COMPONENT PARTS
Component Parts LocationINFOID:0000000006248458
1. ICC steering switch 2. Information display, ICC system warning lamp, IBA OFF indicator
lamp, buzzer
(On the combination meter)3. BCM
Refer to BCS-4, "
BODY CONTROL
SYSTEM : Compon ent Parts Loca-
tion"
4. Transfer control unit
Refer to DLN-10, "
Component Parts
Location"
5. ICC brake hold relay 6. ECM
Refer to EC-16, "
Component Parts
Location"
7. ICC sensor 8. TCM
Refer to TM-10, "
A/T CONTROL
SYSTEM : Compon ent Parts Loca-
tion"
9. ABS actuator and electric unit (con-
trol unit)
Refer to BRC-10, "
Component Parts
Location"
10. Stop lamp switch 11. ICC brake switch 12. IBA OFF switch
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Revision: 2010 May2011 QX56

BRC-150
< SYSTEM DESCRIPTION >[INTELLIGENT BRAKE ASSIST]
COMPONENT PARTS
Component Description
INFOID:0000000006248459
× : Applicable
13. Steering angle sensor
Refer to BRC-10, "
Component Parts
Location"
14. ADAS control unit
Refer to DAS-13, "
Component Parts
Location"
A. Back side of engine room (RH) B. Front bumper (center) C. Upper side of brake pedal
D. Under side of inst rument lower driver
panel
Component Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
ADAS control unit ×××× ADAS control unit calculates a target distance between vehicles
and a target speed, based on signals received from each sensor
and switch to transmit an engine torque command value to ECM
and a brake fluid pres sure control signal to ABS actuator and
electric unit (control unit) via CAN communication
 ADAS control unit transmits buzzer output signal to combination
meter via CAN communication
ICC sensor ×××× ICC sensor detects light reflected from a vehicle ahead by irra-
diating laser forward and calculates a distance from the vehicle
ahead and a relative speed, based on the detected signal
 ICC sensor transmits the presence/absence of vehicle ahead and the distance from the vehicle to ADAS control unit via ITS
communication
ECM ×××× ECM transmits the accelerator pedal position signal, ICC brake
switch signal, stop lamp switch signal, ICC steering switch sig-
nal, etc. to ADAS control unit via CAN communication
 ECM controls the electric throttle control actuator based on the engine torque demand received from the ADAS control unit via
CAN communication
ABS actuator and electric unit
(control unit) ×××× ABS actuator and electric unit (control unit) transmits the vehicle
speed signal (wheel speed), stop lamp signal and VDC/TCS/
ABS system operation condition to ADAS control unit via CAN
communication
 ABS actuator and electric unit (control unit) controls the brake, based on a brake fluid pressure control signal received from the
ADAS control unit via CAN communication
BCM ×BCM transmits the front wiper request signal to ADAS control unit
via CAN communication
TCM ××TCM transmits the signal related to A/T control to ADAS control
unit via CAN communication
Revision: 2010 May2011 QX56

COMPONENT PARTSBRC-151
< SYSTEM DESCRIPTION > [INTELLIGENT BRAKE ASSIST]
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NOTE:
Only IBA system uses
Combination meter ××××Performs the following operations using the signals received from
the ADAS control unit via the CAN communication
 Displays the ICC system operation status using the meter dis-
play signal
 Illuminates the ICC system warning lamp using the ICC warning
lamp signal
 Illuminates the IBA OFF indicator lamp using the IBA OFF indi- cator lamp signal
 Operates the buzzer (ICC warning chime) using the buzzer out- put signal
ICC steering switch ×× ICC steering switch allows the ON/OFF of the Intelligent Cruise
Control and the settings of a vehicle speed and distance be-
tween vehicles
 ICC steering switch signal is transmitted to ECM. ECM transmits the signal to the ADAS control unit via CAN communication
ICC brake switch ×××× ICC brake switch is turned OFF and stop lamp switch is turned
ON, when depressing the brake pedal
 ICC brake switch signal is input to ECM. These signals are transmitted from ECM to ADAS control unit via CAN communi-
cation
 Stop lamp switch signal is in put to ECM and ABS actuator and
electric unit (control unit). These signals are transmitted from
ECM and ABS actuator and electric unit (control unit) to ADAS
control unit via CAN communication
Stop lamp switch
××××
ICC brake hold relay ××ICC brake hold relay activates the stop lamp by ICC brake hold re-
lay drive signal (stop lamp drive signal) outputted by the ADAS
control unit
Transfer control unit ××××Transfer control unit transmits a mode selection state of 4WD shift
switch to the ADAS control unit via CAN communication
IBA OFF switch ×
NoteIBA OFF switch signal is input to the ADAS control unit
Steering angle sensor ×Measures the rotation amount, rotation speed, and rotation direc-
tion of steering wheel, and then transmits them to ADAS control
unit via CAN communication
Component
Function
Description
Vehicle-to-vehicle distance control mode
Conventional (fixed speed) cruise control mode Intelligent Brake Assist (IBA)
Brake Assist (with preview function)
Revision: 2010 May2011 QX56

NORMAL OPERATING CONDITIONBRC-157
< SYMPTOM DIAGNOSIS > [INTELLIGENT BRAKE ASSIST]
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NORMAL OPERATING CONDITION
DescriptionINFOID:0000000006228304
PRECAUTIONS FOR INTELLIGENT BRAKE ASSIST
 The IBA system is a not collision avoidance system. It is the driver′s responsibility to stay alert, drive safely
and be in control of the vehicle at all times.
 As there is a performance limit, it may not prov ide a warning or brake in certain conditions.
 The system will not detect the following objects:
- Pedestrians, animals, or obstacles in the roadway
- Oncoming vehicles in the same lane
 The system will not detect under the following conditions:
- When the sensor gets dirty and it is impossibl e to detect the distance from the vehicle ahead.
- When driving into a strong light (i.e. sunlight)
 The sensor generally detects the signals returned from the reflectors on a vehicle ahead. Therefore, the sys-
tem may not function properly under the following conditions:
- When the reflectors of the vehicle ahead are positioned high or close each other (including a small vehicle
such as motorcycles).
- When the sensor gets dirty or and it is impossi ble to detect the distance from the vehicle ahead.
- When the reflectors on the vehicle ahead is missing, damaged or covered.
- When the reflector of the vehicle ahead is covered with dirt, snow and road spray.
- When visibility is low (such as rain, fog, snow, etc.).
- When snow or road spray from traveling vehicles are raised up.
- When dense exhaust or other smoke (black smoke) fr om vehicles reduces the sensor visibility.
- When excessively heavy baggage is loaded in the rear seat or the luggage room of vehicle.
- When abruptly accelerating or decelerating.
- On steep downhill or roads with sharp curves.
- When there is a highly reflective object near the vehicle ahead (i.e. very close to other vehicle, signboard,
etc.).
- While towing a trailer or other vehicle.
 Depending on certain road conditions (curved, beginning of a curve), vehicle conditions (steering position,
vehicle position), or preceding vehicle ′s conditions (position in lane, etc. ), the system may not function prop-
erly.
 The system may not function in offset conditions.
 The system may not function when the distanc e to the vehicle ahead is extremely close.
 The system detect highly reflective objects such as reflectors, signs, white markers, and other stationary objects on the road or
near the traveling lane, and when in extreme conditions, detection
of these objects may caus e the system to function.
 The system is designed to automatically check the sensor ′s func-
tionality. If the sensor is covered with ice, a transparent or translu-
cent plastic bag, etc., the system may not detect them. In these
instances the system may not be able to warn properly. Be sure to
check and clean the sensor regularly.
 Excessive noise will interfere with the warning chime sound, and the chime may not be heard.
 Never step in under the brake pedal to avoid an accident when IBA
system turns ON.
 Sudden appearance of the vehicle in front (i.e. it abrupt ly cuts in) may not be detected and the system may
not warn soon enough.
 The system will be cancelled automatically with a beep sound and the IBA OFF indicator lamp will illuminate
under the following conditions:
- When the sensor window is dirty
- When the system malfunctions
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Revision: 2010 May2011 QX56