2011 INFINITI QX56 4WD

BRC-42
< SYSTEM DESCRIPTION >[WITH VDC]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
Note 1: Refer to BRC-16, "System Description" for ON/OFF conditions of each warning lamp and indicator
lamp.
Note 2: Models with 4WD System
Note 3: Models with Advanced Driver Assistance System
Note 4: USS means “hill start assist”
ACTIVE TEST
The active test is used to determine and identify details of a malfunction, based on self-diagnosis test result
sand data obtained in the DATA MONITOR. In response to instructions from CONSULT-III, instead of those
SV2
(On/Off) Suction valve 2 operation status is displayed.
STOP LAMP SW2
(On/Off) Stop lamp switch signal input status is displayed.
ACCEL POS SIG
(%) ×
Displays the Accelerator pedal position
SIDE G-SENSOR
(m/s
2) ×
Side G detected by side G sensor is displayed.
STR ANGLE SIG
( ° ) ×
Steering angle detected by steering angle sensor is dis-
played.
PRESS SENSOR
(bar) ×Detects the brake fluid pressure of master cylinder part is
displayed.
ACCUM PRESS SEN
(bar) Detects the brake fluid pressure of accumulator is dis-
played.
CONT PRESS SEN
(Note 3)
(bar) Detects the brake fluid pressure of control pressure sensor
is displayed
EBD SIGNAL
(On/Off) EBD operation status is displayed.
ABS SIGNAL
(On/Off) ABS operation status is displayed.
TCS SIGNAL
(On/Off) TCS operation status is displayed.
VDC SIGNAL
(On/Off) VDC operation status is displayed.
EBD FAIL SIG
(On/Off) EBD fail-safe signal status is displayed.
ABS FAIL SIG
(On/Off) ABS fail-safe signal st
atus is displayed.
TCS FAIL SIG
(On/Off) TCS fail-safe signal status is displayed.
VDC FAIL SIG
(On/Off) VDC fail-safe signal status is displayed.
CRANKING SIG
(On/Off) Cranking status is displayed.
FLUID LEV SW
(On/Off) ×Brake fluid level signal input status via CAN communication
is displayed.
PARK BRAKE SW
(On/Off) ×Parking brake switch signal input status via CAN communi-
cation is displayed.
STP ON RLY
(On/Off) Stop lamp switch relay status is displayed.
USS SIG
(Note 4)
(On/Off) hill start assist operation status is displayed.
Item (Unit)
Monitor item selection
Note
INPUT SIGNALS MAIN ITEMS
Revision: 2010 May2011 QX56

BRC-46
< ECU DIAGNOSIS INFORMATION >[WITH VDC]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
ABS WARN LAMPWhen ABS warning lamp is ON
(Note 2)On
When ABS warning lamp is OFF
(Note 2)Off
OFF LAMP When VDC OFF indicator lamp is ON
(Note 2)On
When VDC OFF indicator lamp is OFF
(Note 2)Off
OFF SW VDC OFF switch ON On
VDC OFF switch OFF Off
SLIP/VDC LAMP When VDC warning lamp is ON or Blinking
(Note 2)On
When VDC warning lamp is OFF
(Note 2)Off
BATTERY VOLT Ignition switch ON 10 – 16 V
GEAR Driving 1 – 7
Depending on shift status
ENGINE SPEED Engine stopped 0 tr/min
Engine running Almost same reading as tachometer
YAW RATE SEN Vehicle stopped Approx. 0 d/s
Turning right Negative value
Turning left Positive value
R POSI SIG When selector lever is in the R position On
When selector lever is in the other position than R Off
4WD MODE MON
(Note 3)
When 4WD sift switch is AUTO position AUTO
When 4WD sift switch is 4H position LOCK
When 4WD sift switch is 4L position ##
N POSI SIG When selector lever is in the N position On
When selector lever is in the other position than N Off
CV1 Active On
Inactive Off
CV2 Active On
Inactive Off
SV1 Active On
Inactive Off
SV2 Active On
Inactive Off
STOP LAMP SW2 Brake pedal depressed On
Brake pedal not depressed Off
ACCEL POS SIG Never depress accelerator pedal
(with ignition switch ON)
0%
Depress accelerator pedal
(with ignition switch ON) 0 – 100%
SIDE G-SENSOR Vehicle stopped
Approx. 0 m/s
2
Right turn Negative value
Left turn Positive value
STR ANGLE SIG When driving straight 0
±2.5 °
When steering wheel is steered to LH by 90 °Approx. +90 °
When steering wheel is steered to RH by 90 °Approx. –90 °
Monitor item Condition Reference values in normal operation
Revision: 2010 May2011 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-47
< ECU DIAGNOSIS INFORMATION > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
Note 1: Confirm tire pressure is standard value.
Note 2: Refer to BRC-16, "
System Description" for ON/Blinking/OFF conditions of each warning lamp and indi-
cator lamp.
Note 3: Models with 4WD System
Note 4: Models with Advanced Driver Assistance System
Note 5: USS means “hill start assist”.
Fail-safeINFOID:0000000006222580
VDC FUNCTION, TCS FUNCTION, hill start assi st FUNCTION AND BRAKE LIMITED SLIP DIFFER-
ENTIAL (BLSD) FUNCTION
VDC warning lamp in combination meter turn ON w hen a malfunction occurs in system [ABS actuator and
electric unit (control unit)]. The control is suspended for VDC function, TCS function, hill start assist function
and brake limited slip differential (BLSD) function. T he Vehicle status becomes the same as models without
PRESS SENSORBrake pedal not depressed Approx. 0 bar
Brake pedal depressed (
−40) – (+300) bar
ACCUM PRESS SEN With ig nition switch ON Approx. 0 – 210 bar (Proportional to the
amount of accumulated pressure in the
accumulator)
CONT PRESS SEN
(Note 4)Brake pedal not depressed Approx. 0 bar
Brake pedal depressed ( −40) – (+300) bar
EBD SIGNAL EBD is active On
EBD is inactive Off
ABS SIGNAL ABS is active On
ABS is inactive Off
TCS SIGNAL TCS is active On
TCS is inactive Off
VDC SIGNAL VDC is active On
VDC is inactive Off
EBD FAIL SIG In EBD fail-safe On
EBD is normal Off
ABS FAIL SIG In ABS fail-safe On
ABS is normal Off
TCS FAIL SIG In TCS fail-safe On
TCS is normal Off
VDC FAIL SIG In VDC fail-safe On
VDC is normal Off
CRANKING SIG At cranking On
Other than at cranking Off
FLUID LEV SW When brake fluid level switch is ON (brake fluid level
is less than the specified level)
On
When brake fluid level switch is OFF Off
PARK BRAKE SW When parking brake is active On
Parking brake is released Off
STP ON RLY Stop lamp relay is active On
Stop lamp relay is inactive Off
USS SIG
(Note 5)hill start assist is active On
hill start assist is inactive Off
Monitor item Condition Reference values in normal operation
Revision: 2010 May2011 QX56

BRC-50
< ECU DIAGNOSIS INFORMATION >[WITH VDC]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
*1: Models with 4WD System
*2: Models with Advanced Driver Assistance System
Protection FunctionINFOID:0000000006222581
The VDC warning lamp, ABS warning lamp and brake warning lamp turns ON and DTC “C118E” may be
detected in self-diagnosis result of “ABS” when the br
ake pedal is excessively operated, such as air bleeding.
This is not a system malfunction because this occurs due to the temporary decrease in accumulator fluid pres-
sure. The system returns to normal condition when the accu mulator fluid pressure reaches the specified pres-
sure with the ignition switch ON and the VDC warning lamp, ABS warning lamp, and brake warning lamp turn
OFF. After these steps, erase self-diagnos is results for “ABS” with CONSULT-III.
NOTE:
D T C “ C 1111 ” i s d e t e c t e d i n s e l f - d i agnosis results of “ABS” when the a ccumulator system has a malfunction.
DTC Inspection Priority ChartINFOID:0000000006222582
When multiple DTCs are displayed simultaneously, check one by one depending on the following priority list.
C1170 When the information in ABS actuator and electric unit (control unit) is not the same. The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C118E When performing excessive brake pedal operation with the vehicle stopped. [When
accumulator fluid pressure reaches 11.43 MPa (114 bar, 116.6 kg/cm
2, 1657 psi) af-
ter reaching 17.3 MPa (173 bar, 176.5 kg/cm2, 2509 psi.] The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential
(BLSD) function
U1000 When CAN communication signal is not continuously received for 2 seconds or
more. The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
DTC Malfunction detected condition Fail-safe condition
DTC
 VDC warning lamp
 ABS warning lamp
 Brake warning lamp Condition Description protection function
C118E ON When temporary decrease in accumulator fluid pres-
sure.
NOTE:
System is not malfunction. The following functions are suspended
temporarily
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential (BLSD)
function
Priority Detected item (DTC)
1  U1000 CAN COMM CIRCUIT
2  C1170 VARIANT CODING
Revision: 2010 May2011 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-51
< ECU DIAGNOSIS INFORMATION > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
*: Models with 4WD system
DTC IndexINFOID:0000000006222583
3  C1118 4WD SYSTEM
*
 C1130 ENGINE SIGNAL 1
 C1144 ST ANG SEN SIGNAL
4  C1109 BATTERY VOLTAGE [ABNORMAL]
 C 1111 P U M P M O T O R
C1140 ACTUATOR RLY
5  C1101 RR RH SENSOR-1
 C1102 RR LH SENSOR-1
 C1103 FR RH SENSOR-1
 C1104 FR LH SENSOR-1
 C1105 RR RH SENSOR-2
 C1106 RR LH SENSOR-2
 C1107 FR RH SENSOR-2
 C1108 FR LH SENSOR-2
 C1115 ABS SENSOR [ABNORMAL SIGNAL]
 C1116 STOP LAMP SW
 C1120 FR LH IN ABS SOL
 C1121 FR LH OUT ABS SOL
 C1122 FR RH IN ABS SOL
 C1123 FR RH OUT ABS SOL
 C1124 RRLH IN ABS SOL
 C1125 RR LH OUT ABS SOL
 C1126 RR RH IN ABS SOL
 C1127 RR RH OUT ABS SOL
 C1142 PRESS SEN CIRCUIT
 C1143 ST ANG SEN CIRCUIT
 C1145 YAW RATE SENSOR
 C1146 SIDE G-SEN CIRCUIT
 C1160 DECEL G SEN SET
C1164 CV 1
C1165 CV 2
 C1166 SV 1
 C1167 SV 2
6  C1155 BR FLUID LEVEL LOW
 C118E ACCUMULATOR PRESS
Priority Detected item (DTC)
DTC Items (CONSULT screen terms) Reference
C1101 RR RH SENSOR-1
BRC-68, "
DTC Logic"C1102 RR LH SENSOR-1
C1103 FR RH SENSOR-1
C1104 FR LH SENSOR-1
C1105 RR RH SENSOR-2BRC-70, "
DTC Logic"C1106 RR LH SENSOR-2
C1107 FR RH SENSOR-2
C1108 FR LH SENSOR-2
C1109 BATTERY VOLTAGE [ABNORMAL]BRC-72, "
DTC Logic"
C 1111 P U M P M O T O RBRC-75, "DTC Logic"
C1115 ABS SENSOR [ABNORMAL SIGNAL] BRC-77, "DTC Logic"
C1116 STOP LAMP SWBRC-79, "DTC Logic"
C 111 8*4WD SYSTEMBRC-87, "DTC Logic"
C1120 FR LH IN ABS SOL BRC-88, "DTC Logic"
Revision: 2010 May2011 QX56

BRC-52
< ECU DIAGNOSIS INFORMATION >[WITH VDC]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
*: Models with 4WD system
C1121 FR LH OUT ABS SOL
BRC-90, "DTC Logic"
C1122 FR RH IN ABS SOLBRC-88, "DTC Logic"
C1123 FR RH OUT ABS SOLBRC-90, "DTC Logic"
C1124 RRLH IN ABS SOLBRC-88, "DTC Logic"
C1125 RR LH OUT ABS SOLBRC-90, "DTC Logic"
C1126 RR RH IN ABS SOLBRC-88, "DTC Logic"
C1127 RR RH OUT ABS SOLBRC-90, "DTC Logic"
C1130 ENGINE SIGNAL 1BRC-92, "DTC Logic"
C1140 ACTUATOR RLYBRC-93, "DTC Logic"
C1142 PRESS SEN CIRCUITBRC-95, "DTC Logic"
C1143 ST ANG SEN CIRCUITBRC-97, "DTC Logic"
C1144 ST ANG SEN SIGNALBRC-99, "DTC Logic"
C1145 YAW RATE SENSOR
BRC-100, "DTC Logic"C1146 SIDE G-SEN CIRCUIT
C1155 BR FLUID LEVEL LOWBRC-103, "
DTC Logic"
C1160 DECEL G SEN SETBRC-105, "DTC Logic"
C1164 CV 1
BRC-106, "DTC Logic"C1165 CV 2
C1166 SV 1BRC-108, "
DTC Logic"C1167 SV 2
C1170 VARIANT CODING BRC-110, "
DTC Logic"
C118E ACCUMULATOR PRESS BRC-111, "DTC Logic"
U1000 CAN COMM CIRCUITBRC-112, "DTC Logic"
DTC Items (CONSULT screen terms) Reference
Revision: 2010 May2011 QX56

C1118 TRANSFER CONTROL UNITBRC-87
< DTC/CIRCUIT DIAGNOSIS > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
C1118 TRANSFER CONTROL UNIT
DTC LogicINFOID:0000000006222607
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
“C 111 8” detected?
YES >> Proceed to diagnosis procedure. Refer to BRC-87, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222608
1.CHECK TRANSFER CO NTROL UNIT SYSTEM
With CONSULT-III.
Perform self-diagnosis for “ALL MODE AWD/4WD”.
Is any DTC detected?
YES >> Check the DTC.
NO >> GO TO 2.
2.CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
With CONSULT-III.
1. Erase Self-diagnosis result for “ABS”.
2. Turn the ignition switch OFF.
3. Start the engine and drive the vehicle for a short period of time.
4. Check that the 4WD warning lamp turns OFF.
5. After the vehicle stops, perform self-diagnosis for “ABS”.
Is DTC
“C 111 8” detected?
YES >> Replace ABS actuator and electric unit (control unit). Refer to BRC-137, "Removal and Installa-
tion".
NO >> Check pin terminals and connection of each harness connector for abnormal conditions. Repair or
replace error-detected parts.
DTC Display Item Malfunction detected condition Possible causes
C1118 4WD SYSTEM When a malfunction is detected in transfer control unit
system.  Transfer control unit
 ABS actuator and electric unit
(control unit)
 CAN communication line
Revision: 2010 May2011 QX56

VDC OFF SWITCHBRC-119
< DTC/CIRCUIT DIAGNOSIS > [WITH VDC]
C
D
E
G H
I
J
K L
M A
B
BRC
N
O P
VDC OFF SWITCH
Component Function CheckINFOID:0000000006222646
1.CHECK VDC OFF SWITCH OPERATION
Check that VDC OFF indicator lamp in combinati on meter turns ON/OFF when VDC OFF switch is operated.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Proceed to diagnosis procedure. Refer to BRC-119, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006222647
NOTE:
VDC OFF switch is integrated in SNOW MODE / TOW MODE / VDC OFF switch assembly (2WD models) or
4WD switch assembly (4WD models).
1.CHECK VDC OFF SWITCH CIRCUIT
1. Turn the ignition switch OFF.
2. Disconnect ABS actuator and electric unit (control unit) harness connector.
3. Disconnect SNOW MODE / TOW MODE / VDC OFF s witch assembly (2WD models) or 4WD switch
assembly (4WD models) harness connector.
4. Check continuity between ABS actuator and elec tric unit (control unit) harness connector and SNOW
MODE / TOW MODE / VDC O FF switch assembly (2WD models) or 4WD switch assembly (4WD models)
harness connector.
*1: SNOW MODE / TOW MODE / VDC OFF switch assembly (2WD models)
*2: 4WD switch assembly (4WD models)
5. Check continuity between ABS actuator and electr ic unit (control unit) harness connector terminal and
ground.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace error-detected parts.
2.CHECK VDC OFF SW ITCH GROUND CIRCUIT
Check continuity between SNOW MODE / TOW MODE / VDC OFF switch assembly (2WD models) or 4WD
switch assembly (4WD models) harness connector terminal and ground.
*1: SNOW MODE / TOW MODE / VDC OFF switch assembly (2WD models)
*2: 4WD switch assembly (4WD models)
ABS actuator and electric unit (control unit)SNOW MODE / TOW MODE / VDC OFF
switch assembly (2WD models) or 4WD switch assembly (4WD models) Continuity
Connector Terminal Connector Terminal
E36 39 M147
*1
M54*21 Existed
ABS actuator and electric unit (control unit) —Continuity
Connector Terminal
E36 39 Ground Not existed
SNOW MODE / TOW MODE / VDC
OFF switch assembly (2WD models) or 4WD switch assembly (4WD models) —Continuity
Connector Terminal M147
*1
M54*220 Ground Existed
Revision: 2010 May2011 QX56