2006 INFINITI QX56 steering

BRC-8
[VDC/TCS/ABS]
SYSTEM DESCRIPTION
Revision: November 20092006 QX56
ABS FunctionEFS004XC

The Anti-Lock Brake System detects wheel revolution while braking and improves handling stability during
sudden braking by electrically preventing wheel lockup. Maneuverability is also improved for avoiding
obstacles.

If the electrical system malfunctions, the Fail-Safe function is activated, the ABS becomes inoperative and
the ABS warning lamp turns on.

The electrical system can be diagnosed using CONSULT-II.

During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.

Just after starting the vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.

Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel,
or snow-covered (fresh, deep snow) roads.
EBD FunctionEFS004XD

Electronic Brake Distribution is a function that detects subtle slippages between the front and rear wheels
during braking, and it improves handling stability by electronically controlling the brake fluid pressure
which results in reduced rear wheel slippage.

If the electrical system malfunctions, the Fail-Safe function is activated, the EBD and ABS become inoper-
ative, and the ABS warning lamp and BRAKE warning lamp are turned on.

The electrical system can be diagnosed using CONSULT-II.

During EBD operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.

Just after starting the vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.
TCS FunctionEFS004XE

Spinning of the drive wheels is detected by the ABS actuator and electric unit (control unit) using inputs
from the wheel speed sensors. If wheel spin occurs, the drive wheel right and left brake fluid pressure
control and engine fuel cut are activated while the throttle value is restricted to reduce the engine torque
and decrease the amount of wheel spin. In addition, the throttle opening is controlled to achieve the opti-
mum engine torque.

Depending on road condition, the vehicle may have a sluggish feel. This is normal, because optimum trac-
tion has the highest priority during TCS operation.

TCS may be activated during sudden vehicle acceleration, wide open throttle acceleration, sudden trans-
mission shifts or when the vehicle is driven on a road with a varying surface friction coefficient.

The SLIP indicator lamp flashes to inform the driver of TCS operation.
VDC FunctionEFS004XF

In addition to the ABS/TCS function, the driver steering amount and brake operation amount are detected
from the steering angle sensor and front and rear pressure sensors, and the vehicle's driving status
(amount of under steering/over steering) is determined using inputs from the yaw rate sensor/side G sen-
sor, wheel speed sensors, etc. and this information is used to improve vehicle stability by controlling the
braking and engine torque application to the wheels.

The SLIP indicator lamp flashes to inform the driver of VDC operation.

During VDC operation, the vehicle body and brake pedal may vibrate lightly and a mechanical noise may
be heard. This is normal.

The ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp may turn on when the vehicle is
subject to strong shaking or large vibration, such as when the vehicle is on a turn table or a ship while the
engine is running or on a steep slope. In this case, restart the engine on a normal road and if the ABS
warning lamp, VDC OFF indicator lamp and SLIP indicator lamp turn off, there is no problem.
Fail-Safe FunctionEFS004XG
CAUTION:
If the Fail-Safe function is activated, perform the Self Diagnosis for ABS/TCS/VDC system.

TROUBLE DIAGNOSISBRC-25
[VDC/TCS/ABS]
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BRC
Revision: November 2009 2006 QX56
STR ANGLE SIGSteering angle
detected by steering
angle sensorStraight-ahead
Approx. 0 deg
BRC-40, "Steering Angle
Sensor System"Steering wheel turned –756 to 756 deg
YAW RATE SEN Yaw rate detected by
yaw rate sensorVehicle stopped Approx. 0 d/s
BRC-41, "
Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running–100 to 100 d/s
SIDE G-SENSOR Transverse G detected
by side G-sensorVehicle stopped
Approx. 0 m/s
2BRC-41, "Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running–16.7 to 16.7 m/s2
BATTERY VOLT Battery voltage sup-
plied to ABS actuator
and electric unit (con-
trol unit)Ignition switch ON
10 to 16VBRC-46, "
ABS/TCS/VDC
Control Unit Power and
Ground Systems Inspec-
tion"
STOP LAMP SW
Stop lamp switch oper-
ationBrake pedal depressed ON
BRC-45, "
Stop Lamp
Switch System Inspec-
tion"Brake pedal not depressed OFF
OFF SW VDC OFF switch
ON/OFF status VDC OFF switch ON
(When VDC OFF indicator
lamp is ON)
ON
BRC-56, "
VDC OFF
SWITCH"VDC OFF switch OFF
(When VDC OFF indicator
lamp is OFF) OFF
ABS WARN LAMP ABS warning lamp ON
condition (Note 2)ABS warning lamp ON ON
—
ABS warning lamp OFF OFF
MOTOR RELAY Operation status of
motor and motor relayIgnition switch ON or running
(ABS not activated)
OFF
BRC-44, "
Actuator Motor,
Motor Relay, and Circuit
Inspection"Ignition switch ON or engine
running (ABS activated) ON
ACTUATOR RLY Actuator relay opera-
tion statusVehicle stopped (Ignition
switch ON)
OFF
BRC-44, "
Actuator Motor,
Motor Relay, and Circuit
Inspection"Vehicle stopped (Engine run-
ning) ON
OFF LAMP VDC OFF indicator
lamp status (Note 3) When VDC OFF indicator
lamp is ON
ON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"When VDC OFF indicator
lamp is OFF OFF
SLIP LAMP SLIP indicator lamp
status (Note 4)When SLIP indicator lamp is
ON
ON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"When SLIP indicator lamp is
OFF OFF
Monitor item
Display content Data monitor
Note: Error inspection
checklist
Condition Reference value in
normal operation

BRC-30
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Display Item List
Self-diagnostic itemMalfunction detecting condition Check system
FR LH SENSOR 1
[C1104] Circuit of front LH wheel sensor is open, shorted or sensor power
voltage is unusual.
BRC-38, "
Wheel Sensor
System Inspection"
(Note 1)
RR RH SENSOR 1
[C1101]
Circuit of rear RH wheel sensor is open, shorted or sensor power
voltage is unusual.
FR RH SENSOR 1
[C1103] Circuit of front RH wheel sensor is open, shorted or sensor power
voltage is unusual.
RR LH SENSOR 1
[C1102] Circuit of rear LH wheel sensor is open, shorted or sensor power
voltage is unusual.
FR LH SENSOR 2
[C1108] ABS actuator and electric unit (control unit) cannot identify sen-
sor pulses, because of large gap between wheel sensor and sen-
sor rotor.
RR RH SENSOR 2
[C1105] ABS actuator and electric unit (control unit) cannot identify sen-
sor pulses, because of large gap between wheel sensor and sen-
sor rotor.
FR RH SENSOR 2
[C1107] ABS actuator and electric unit (control unit) cannot identify sen-
sor pulses, because of large gap between wheel sensor and sen-
sor rotor.
RR LH SENSOR 2
[C1106] ABS actuator and electric unit (control unit) cannot identify sen-
sor pulses, because of large gap between wheel sensor and sen-
sor rotor.
ABS SENSOR
[C1115] Wheel sensor input is abnormal.
STOP LAMP SW
[C1116] Stop lamp switch or circuit malfunction. BRC-45, "
Stop Lamp
Switch System Inspec-
tion"
DECEL G SEN SET
[C1160]
ABS decel sensor adjustment is incomplete. BRC-55, "Inspection For
Self-diagnosis Result
"DECEL G SEN SET""
ST ANGL SEN SAFE
[C1163]
When steering angle sensor is in safe mode. BRC-53, "Steering Angle
Sensor Safe Mode
Inspection"
ST ANG SEN CIRCUIT
[C1143]
Neutral position of steering angle sensor is dislocated, or steer-
ing angle sensor is malfunctioning. BRC-40, "Steering Angle
Sensor System"
YAW RATE SENSOR
[C1145]Yaw rate sensor has generated an error, or yaw rate sensor sig-
nal line is open or shorted. BRC-41, "Yaw Rate/
Side/Decel G Sensor
System Inspection"

TROUBLE DIAGNOSISBRC-31
[VDC/TCS/ABS]
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BRC
Revision: November 2009 2006 QX56
FR LH IN ABS SOL
[C1120]Circuit of front LH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
BRC-43, "
Solenoid and
VDC Change-Over Valve
System Inspection"
FR LH OUT ABS SOL
[C1121]Circuit of front LH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
RR RH IN ABS SOL
[C1126] Circuit of rear RH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
RR RH OUT ABS SOL
[C1127] Circuit of rear RH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
FR RH IN ABS SOL
[C1122] Circuit of front RH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
FR RH OUT ABS SOL
[C1123] Circuit of front RH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
RR LH IN ABS SOL
[C1124] Circuit of rear LH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
RR LH OUT ABS SOL
[C1125] Circuit of rear LH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
CV1
[C1164] Front side VDC switch-over solenoid valve (cut valve) is open or
shorted, or control line is open or shorted to power supply or
ground.
CV2
[C1165] Rear side VDC switch-over solenoid valve (cut valve) is open or
shorted, or control line is open or shorted to power supply or
ground.
SV1
[C1166] Front side VDC switch-over solenoid valve (suction valve) is
open or shorted, or control line is open or shorted to power sup-
ply or ground.
SV2
[C1167] Rear side VDC switch-over solenoid valve (suction valve) is open
or shorted, or control line is open or shorted to power supply or
ground.
PUMP MOTOR
[ C 1111 ] During actuator motor operation with ON, when actuator motor
turns OFF or when control line for actuator motor relay is open.
BRC-44, "
Actuator
Motor, Motor Relay, and
Circuit Inspection"During actuator motor operation with OFF, when actuator motor
turns ON or when control line for relay is shorted to ground.
BATTERY VOLTAGE
[ABNORMAL]
[C1109] ABS actuator and electric unit (control unit) power voltage is too
low. BRC-46, "
ABS/TCS/
VDC Control Unit Power
and Ground Systems
Inspection"
ST ANG SEN SIGNAL
[C1144]
Neutral position correction of steering angle sensor is not fin-
ished. BRC-55, "Inspection For
Self-diagnosis Result
"ST ANG SEN SIGNAL""
ST ANG SEN COM CIR
[C1156]
CAN communication line or steering angle sensor has generated
an error. BRC-40, "Steering Angle
Sensor System"
G-SENSOR
[C1113]Longitudinal G-sensor is malfunctioning, or signal line of longitu-
dinal G-sensor is open or shorted. BRC-41, "Yaw Rate/
Side/Decel G Sensor
System Inspection"
CONTROLLER FAILURE
[C1110]
Internal malfunction of ABS actuator and electric unit (control
unit) BRC-40, "ABS/TCS/
VDC Control Unit
Inspection"
CAN COMM CIRCUIT
[U1000]

CAN communication line is open or shorted.

ABS actuator and electric unit (control unit) internal malfunc-
tion

Battery voltage for ECM is suddenly interrupted for approxi-
mately 0.5 second or more.BRC-54, "
CAN Commu-
nication System Inspec-
tion" (Note 2)
SIDE G-SEN CIRCUIT
[C1146] Lateral G-sensor is malfunctioning, or signal line of lateral G-sen-
sor is open or shorted. BRC-41, "
Yaw Rate/
Side/Decel G Sensor
System Inspection"
Self-diagnostic item
Malfunction detecting condition Check system

TROUBLE DIAGNOSISBRC-33
[VDC/TCS/ABS]
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BRC
Revision: November 2009 2006 QX56
CAUTION:
When “START (NISSAN BASED VHCL)” is touched immediately after starting the engine or turning
on the ignition switch, “ABS” might not be displayed in the SELECT SYSTEM screen. In this case,
repeat the operation from step 2.
3. Return to the SELECT MONITOR ITEM screen, and touch “ECU INPUT SIGNALS”, “MAIN SIGNALS ”, or
“SELECTION FROM MENU ”. Refer to the following information.
4. When “START” is touched, the data monitor screen is displayed.
Display Item List
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
GEAR ××× Gear position judged by PNP
switch signal is displayed.
FR RH SENSOR
(km/h, MPH) ××× Wheel speed calculated by front
RH wheel sensor signal is dis-
played.
FR LH SENSOR
(km/h, MPH) ××× Wheel speed calculated by front LH
wheel sensor signal is displayed.
RR RH SENSOR
(km/h, MPH) ××× Wheel speed calculated by rear RH
wheel sensor signal is displayed.
RR LH SENSOR
(km/h, MPH) ×××
Wheel speed calculated by rear LH
wheel sensor signal is displayed.
BATTERY VOLT
(V) ××× Voltage supplied to ABS actuator
and electric unit (control unit) is dis-
played.
N POSI SIG ––× Shift position judged by PNP switch
signal.
P POSI SIG ––× Shift position judged by PNP switch
signal.
ACCEL POS SIG
(%) ×
–×Throttle valve open/close status
judged by CAN communication sig-
nal is displayed.
ENGINE SPEED
(rpm) ××× Engine speed judged by CAN com-
munication signal is displayed.
STR ANGLE SIG
(deg) ×
–×Steering angle detected by steering
angle sensor is displayed.
YAW R AT E S E N
(d/s) ×××
Yaw rate detected by yaw rate sen-
sor is displayed.
DECEL G-SEN
(d/s) ××× Longitudinal acceleration detected
by decel G-sensor is displayed.
SIDE G-SENSOR
(m/s
2 ) ×
– × Transverse acceleration detected
by side G-sensor is displayed.
STOP LAMP SW
(ON/OFF) ××× Stop lamp switch (ON/OFF) status
is displayed.
OFF SW
(ON/OFF)
×× × VDC OFF switch (ON/OFF) status
is displayed.
ABS WARN LAMP
(ON/OFF) –
×× ABS warning lamp (ON/OFF) status
is displayed.
SLIP LAMP
(ON/OFF) –
×× SLIP indicator lamp (ON/OFF) sta-
tus is displayed.
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 displayed.

BRC-40
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: November 20092006 QX56
ABS/TCS/VDC Control Unit InspectionEFS004XT
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> Replace ABS actuator and electric unit (control unit). Refer to BRC-66, "Removal and Installation"
.
NO >> Inspection End.
Steering Angle Sensor SystemEFS004XU
INSPECTION PROCEDURE
1. CHECK SELF-DIAGNOSIS RESULT
Check self-diagnosis results.
Is above displayed in self-diagnosis item?
YES >> GO TO 2.
NO >> Inspection End.
2. CHECK CONNECTOR
1. Disconnect steering angle sensor connector M47 and ABS actuator and electric unit (control unit) connec- tor E125 and check terminals for deformation, disconnection, looseness, or damage. Repair or replace as
necessary.
2. Reconnect connectors and repeat ABS actuator and electric unit (control unit) self-diagnosis.
Is "ST ANG SEN CIRCUIT" or "ST ANG SEN COM CIR" displayed?
YES >> GO TO 3.
NO >> Inspection End.
3. CHECK STEERING ANGLE SENSOR HARNESS
1. Check CAN communication system. Refer to LAN-26, "
CAN COMMUNICATION" .
2. Turn ignition switch OFF and disconnect steering angle sensor connector M47 and ABS actuator and electric unit (control unit)
connector E125.
3. Check continuity between ABS actuator and electric unit (control unit) connector E125 and steering angle sensor connector M47.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness.
Self-diagnosis results
CONTROLLER FAILURE VARIANT CODING
Self-diagnosis results
ST ANG SEN CIRCUIT
ST ANG SEN COM CIR
ABS actuator and electric unit (con- trol unit) harness connector E125 Steering angle
sensor
harness con- nector M47 Continuity
11 3Yes
15 4Yes
WFIA0224E

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMSBRC-41
[VDC/TCS/ABS]
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BRC
Revision: November 2009 2006 QX56
4. CHECK DATA MONITOR
1. Connect steering angle sensor and ABS actuator and electric unit (control unit) connectors.
2. Use “DATA MONITOR ” to check if the status of "STR ANGLE SIG" is normal.
OK or NG
OK >> Perform ABS actuator and electric unit (control unit) self-diagnosis again.
NG >> Replace spiral cable (steering angle sensor) and adjust neutral position of steering angle sensor. Refer to BRC-62, "
Adjustment of Steering Angle Sensor Neutral Position" .
Yaw Rate/Side/Decel G Sensor System InspectionEFS004XV
CAUTION:
Sudden turns (such as spin turns, acceleration turns), drifting, etc. when VDC function is OFF may
cause the yaw rate/side/decel G sensor system to indicate a problem. This is not a problem if normal
operation can be resumed after restarting the engine.
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
CAUTION:
If vehicle is on turn table at entrance to parking garage, or on other moving surface, VDC OFF indica-
tor lamp may illuminate and CONSULT-II self-diagnosis may indicate yaw rate sensor system malfunc-
tion. However, in this case there is no malfunction in yaw rate sensor system. Take vehicle off of turn
table or other moving surface, and start engine. Results will return to normal.
Is the above displayed in the self-diagnosis display items?
YES >> GO TO 2.
NO >> Inspection End.
2. 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.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
Steering condition Data monitor
Straight-ahead –3.5 deg to +3.5 deg
Turn wheel to the right by 90 ° Approx. - 90deg
Turn wheel to the left by 90 ° Approx. + 90deg
Self-diagnosis results
YAW RATE SENSOR G-SENSOR
SIDE G-SEN CIRCUIT

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMSBRC-53
[VDC/TCS/ABS]
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BRC
Revision: November 2009 2006 QX56
3. REAR PRESSURE SENSOR CIRCUIT INSPECTION
1. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and rear pressure sensor connector E32.
2. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and body ground.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness or connector.
4. REAR PRESSURE SENSOR INSPECTION
1. Reconnect the rear pressure sensor and ABS actuator and electric unit (control unit) connectors.
2. Use "DATA MONITOR" to check if the status of "PRESS SEN 2" is normal.
OK or NG
OK >> Inspection End.
NG >> Replace rear pressure sensor.
Steering Angle Sensor Safe Mode InspectionEFS0068B
INSPECTION PROCEDURE
1. INDICATOR LAMP CHECK
Check that VDC OFF indicator lamp is on.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2. ADJUSTMENT OF STEERING ANGLE SENSOR NEUTRAL POSITION
Adjust steering angle sensor neutral position. Refer to BRC-62, "
Adjustment of Steering Angle Sensor Neutral
Position" .
OK or NG
OK >> GO TO 3.
NG >> Check steering angle sensor. Refer to BRC-40, "
Steering Angle Sensor System" .
ABS actuator and electric unit
(control unit) connector E125 Rear pressure sensor con-
nector E32 Continuity
21 1
Yes
22 3
23 2
ABS actuator and electric unit (control unit) connector E125 Body ground
Continuity
21 —No
22
23
Condition Data monitor display (Approx.)
PRESS SEN 2
When brake pedal is depressed Positive value
When brake pedal is released 0 bar