2011 INFINITI QX56 brake sensor

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-47
< ECU DIAGNOSIS INFORMATION > [WITH VDC]
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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-48
< ECU DIAGNOSIS INFORMATION >[WITH VDC]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
VDC function, TCS function, hill start assist function and
brake limited slip differential (BLSD) function. How-
ever, ABS function and EBD function are operated normally.
ABS FUNCTION
ABS warning lamp and VDC warning lamp in combinati on meter turn ON when a malfunction occurs in system
[ABS actuator and electric unit (control unit)]. The c ontrol is suspended for VDC function, TCS function, ABS
function, hill start assist function and brake limited sl ip differential (BLSD) function. The vehicle status
becomes the same as models without VDC function, TCS f unction, ABS function, hill start assist function and
brake limited slip differential (BLSD) function. However, EBD function is operated normally.
NOTE:
ABS self-diagnosis sound may be heard the same as in the normal condition, because self-diagnosis is per-
formed when ignition switch turns ON and when vehicle initially starts.
EBD FUNCTION
ABS warning lamp, brake warning lamp and VDC warning lamp in combination meter turn ON when a mal-
function occurs in system [ABS actuator and electric unit (control unit)]. The control is suspended for VDC
function, TCS function, ABS function, EBD function, hill start assist function and brake limited slip differential
(BLSD) function. The vehicle status becomes the sa me as models without VDC function, TCS function, ABS
function, EBD function, hill star t assist function and brake limited slip differential (BLSD) function.
DTC Malfunction detected condition Fail-safe condition
C1101 When an open circuit is detected in rear RH wheel sensor circuit.
The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 EBD function (only when both 2 rear wheels are malfunctioning)
 hill start assist function
 Brake limited slip differential (BLSD) function
C1102 When an open circuit is detected in rear LH wheel sensor circuit.
C1103 When an open circuit is detected in front RH wheel sensor circuit.
C1104 When an open circuit is detected in front LH wheel sensor circuit.
C1105
 When power supply voltage of rear RH wheel sensor is low.
 When distance between rear RH wheel sensor and rear RH wheel sensor rotor is
large.
 When installation of rear RH wheel sensor or rear RH wheel sensor rotor is not normal.
C1106  When power supply voltage of rear LH wheel sensor is low.
 When distance between rear LH wheel sensor and rear LH wheel sensor rotor is
large.
 When installation of rear LH wheel sensor or rear LH wheel sensor rotor is not nor-
mal.
C1107  When power supply voltage of front RH wheel sensor is low.
 When distance between front RH wheel sensor and front RH wheel sensor rotor
is large.
 When installation of front RH wheel sensor or front RH wheel sensor rotor is not normal.
C1108  When power supply voltage of front LH wheel sensor is low.
 When distance between front LH wheel sensor and front LH wheel sensor rotor is
large.
 When installation of front LH wheel sensor or front LH wheel sensor rotor is not normal.
C1109  When ignition voltage is 10 V or less.
 When ignition voltage is 16 V or more. The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C 1111
 When a malfunction is detected in motor or motor relay.
 When a low pressure malfunction is detected in accumulator.
 When a malfunction is detected in accumulator pressure sensor.
Revision: 2010 May2011 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-49
< ECU DIAGNOSIS INFORMATION > [WITH VDC]
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C 111 5 When difference in wheel speed between any wheel and others is detected during
the vehicle is driven, because of installation of other tires than specified. The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C 111 6
 When stop lamp switch signal is not input when brake pedal depress.
 When stop lamp switch signal is not input when stop lamp relay operates.
C 111 8
*1When a malfunction is detected in transfer control unit system.
C1120 When a malfunction is detec ted in front LH ABS IN valve.
The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential (BLSD) function
C1121 When a malfunction is detec
ted in front LH ABS OUT valve.
C1122 When a malfunction is detected in front RH ABS IN valve.
C1123 When a malfunction is det ected in front RH ABS OUT valve.
C1124 When a malfunction is detected in rear LH ABS IN valve.
C1125 When a malfunction is detected in rear LH ABS OUT valve.
C1126 When a malfunction is det ected in rear RH ABS IN valve.
C1127 When a malfunction is detected in rear RH ABS OUT valve.
C1130 When a malfunction is detected in ECM system. The following functions are sus-
pended.
 VDC function
 TCS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C1140 When a malfunction is detected in actuator relay. The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C1142
*2When a malfunction is detected in master cylinder pressure sensor or control pres-
sure sensor. The following functions are sus-
pended.
 VDC function
 TCS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C1143 When a malfunction is detected in steering angle sensor.
C1144 When neutral position adjustment of steering angle sensor is not complete.
C1145
 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.
The following functions are sus-
pended.
 VDC function
 TCS function
 ABS function
 hill start assist function
 Brake limited slip differential
(BLSD) function
C1146 When a malfunction is detected in side/decel G signal.
C1155
 When brake fluid level low signal is detected.
 When an open circuit is detected in brake fluid level switch circuit.
C1160 When calibration of yaw rate/side/decal G sensor is not complete.
C1164 When a malfunction is detected in cut valve 1. The following functions are sus- pended.
 VDC function
 TCS function
 ABS function
 EBD function
 hill start assist function
 Brake limited slip differential (BLSD) function
C1165 When a malfunction is detected in cut valve 2.
C1166 When a malfunction is detected in suction valve 1.
C1167 When a malfunction is detected in suction valve 2. DTC Malfunction detected condition Fail-safe condition
Revision: 2010 May2011 QX56

C1111 PUMP MOTORBRC-75
< DTC/CIRCUIT DIAGNOSIS > [WITH VDC]
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C1111 PUMP MOTOR
DTC LogicINFOID:0000000006222599
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.CHECK DTC DETECTION
With CONSULT-III.
1. Turn the ignition switch OFF and depress the brake pedal 20 times or more.
2. Start the engine and wait for 3 minutes or more. CAUTION:
Never drive the vehicle.
3. Depress the brake pedal, and then operate the ABS act uator and electric unit (control unit) motor repeats
ON and OFF 4 times or more.
CAUTION:
Never drive the vehicle.
4. Perform self-diagnosis for “ABS”.
Is DTC
“C 1111” detected?
YES >> Proceed to diagnosis procedure. Refer to BRC-75, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006222600
1.CHECK ABS MOTOR AND MOTOR RELAY POWER SUPPLY
1. Turn the ignition switch OFF.
2. Disconnect ABS actuator and electric unit (control unit) harness connector.
3. Check voltage between ABS actuator and electr ic unit (control unit) harness connector and ground.
4. Turn the ignition switch ON. CAUTION:
Never start engine.
5. Check voltage between ABS actuator and electr ic unit (control unit) harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.CHECK ABS MOTOR AND MOTOR RELAY POWER SUPPLY CIRCUIT
DTC Display Item Malfunction detected condition Possible causes
C 1111 P U M P M O T O R  When a malfunction is detected in motor or motor
relay.
 When a low pressure malfunction is detected in ac- cumulator.
 When a malfunction is detected in accumulator
pressure sensor.  Harness or connector
 ABS actuator and electric unit
(control unit)
Fusible link
 Battery power supply system
 Motor/accumulator assembly
ABS actuator and electric unit (control unit)
—Voltage
Connector Terminal
E36 4 Ground Battery voltage
E37 47
ABS actuator and electric unit (control unit)
—Voltage
Connector Terminal
E36 4 Ground Battery voltage
E37 47
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

EXCESSIVE OPERATION FREQUENCYBRC-127
< SYMPTOM DIAGNOSIS > [WITH VDC]
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SYMPTOM DIAGNOSIS
EXCESSIVE OPERATION FREQUENCY
DescriptionINFOID:0000000006222657
VDC function, TCS function, ABS functi on, EBD function, hill start assist function and brake limited slip differ-
ential (BLSD) function operates in excessive operation frequency.
Diagnosis ProcedureINFOID:0000000006222658
1.CHECK BRAKING FORCE
Check brake force using a brake tester.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Check brake system.
2.CHECK FRONT AND REAR AXLE
Check that there is no excessive looseness in front and rear axle.
 Front axle: Refer to FA X - 7 , "
Inspection" (2WD), FAX-16, "Inspection" (4WD).
 Rear axle: Refer to RAX-5, "
Inspection"
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace error-detected parts.
3.CHECK WHEEL SENSOR
Check wheel sensor.
 Check installation and damage of wheel sensor.
 Check connection of wheel sensor harness connector.
 Check terminal of wheel sensor harness connector.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace wheel sensor.  Front wheel sensor: Refer to BRC-134, "
FRONT WHEEL SENSOR : Removal and Installation".
 Rear wheel sensor: Refer to BRC-135, "
REAR WHEEL SENSOR : Removal and Installation".
4.CHECK WARNING LAMP TURNS OFF
Check that ABS warning lamp, brake warning lamp and VDC warning lamp turn OFF approx. 1 second after
key switch is turned ON and stay in OFF status during driving.
CAUTION:
Brake warning lamp turns ON when parking brake is operated (parking brake switch is ON) or brake
fluid is less than the specified level (brake fluid level switch is ON).
Is the inspection result normal?
YES >> Normal
NO >> Perform self-diagnosis for “ABS” with CONSULT-III.
Revision: 2010 May2011 QX56

NORMAL OPERATING CONDITIONBRC-133
< SYMPTOM DIAGNOSIS > [WITH VDC]
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NORMAL OPERATING CONDITION
DescriptionINFOID:0000000006222669
Symptom Result
Brake pedal slightly vibrates and operation sound (motor sound and sound from suspen-
sion) occurs when VDC function, TCS function, ABS function, EBD function, hill start assist
function and brake limited slip differential (BLSD) function operates. This is not a malfunction, The symptom
occurs VDC function
, TCS function, ABS
function, EBD function, hill start assist
function and brake limited slip differential
(BLSD) function that are normally operat-
ed.
Brake stopping distance may become longer than models without ABS function depending
on the road conditions, when
ABS function is operated on slip pery road like rough road,
gravel road or snowy road.
Brake pedal vibrates and operation sound occurs during sudden acceleration and corner-
ing, when VDC function, TCS function, hill start assist function and brake limited slip differ-
ential (BLSD) function is operated.
Brake pedal vibrates and motor sound from the engine room occurs, when the engine starts
or the vehicle starts just after starting the engine This is not a malfunction. The symptom
occurs during the brake fluid accumula-
tion in the accumulator and operational
check of the ABS actuator and electric
unit (control unit).
Acceleration may be felt insufficient depending on the road conditions. This is not a malfunction. The symptom occurs TCS function that puts the highest
priority to obtain the optimum traction
(stability).
TCS may operate momentarily, while driving on a road where friction coefficient varies, or
when downshifting or fully depressing accelerator pedal
ABS warning lamp and VDC warning lamp may turn ON, when the vehicle is on a rotating
turntable or is given a strong shaking or large vibrations on a ship while the engine is run-
ning.
In this case, restart the engine on a nor-
mal road. If the normal condition is re-
stored, there is no malfunction. In that
case, erase self-diagnosis result memory
for “ABS” with CONSULT-III.
VDC warning lamp may turn ON and VDC function, TCS function, hill start assist function
and brake limited slip differential (BLSD) function may not normally operate, when driving
on a special road the is extremely slanted (bank in a circuit course).
A malfunction in yaw rate/side/decel G sensor system may be detected when the vehicle
sharply turns during a spin turn, acceleration turn or drift driving while VDC function and
TCS function are OFF (VDC OFF switch is pressed and VDC OFF indicator lamp is in ON
status).
The vehicle speed does not increase, when the accelerator pedal is depressed while the
vehicle is on a 2-wheel chassis dynamometer for speedometer check.
This is not malfunction. (When checking
the vehicle on a chassis dynamometer,
operate VDC OFF switch so that TCS
function is OFF.)
The VDC warning lamp, ABS warn ing lamp and brake warning lamp turn ON and DTC
“C118E” may be detected in self-diagnosis resu lt of “ABS” when the brake pedal is exces-
sively operated, such as air bleeding. This is not a system malfunction because
this occurs due to the temporary de-
crease in accumulator fluid pressure. The
system returns to no
rmal condition when
the accumulator fluid pressure reaches
the specified pressure with the ignition
switch ON and the VDC warning lamp,
ABS warning lamp, a nd brake warning
lamp turn OFF. After these steps, ABS
self-diagnosis results are erased.
VDC OFF indicator lamp turns ON and TCS function is not operate when 4WD mode is “4L”.
(Models with 4WD system) This is not a malfunction. When the 4WD
mode becomes “4L” state, the TCS func-
tion is disabled. This function is enabled
when the 4WD mode becomes “AUTO”
or “4H”.
Revision: 2010 May2011 QX56