2004 INFINITI QX56 brake sensor

BRC-32
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Note 1. If wheel sensor 2 for each wheel is indicated, check ABS actuator and electric unit (control unit) power
supply voltage in addition to wheel sensor circuit check.
Note 2. If multiple malfunctions are detected including CAN communication line [U1000], perform diagnosis for
CAN communication line first.
Note 3: "ACTUATOR RLY" on the CONSULT-II self-diagnosis results indicates the malfunction of the actuator
motor relay or circuit.
DATA MONITOR
Operation Procedure
1. After turning OFF the ignition switch, connect CONSULT-II and the CONSULT-II CONVERTER to the data
link connector.
SIDE G-SEN CIRCUIT
[C1146]Lateral G-sensor is malfunctioning, or signal line of lateral G-sen-
sor is open or shorted.BRC-41, "Ya w R a t e /
Side/Decel G Sensor
System Inspection"
BR FLUID LEVEL LOW
[C1155]Brake fluid level drops or circuit between ABS actuator and elec-
tric unit (control unit) and brake fluid level switch is open or
shorted.BRC-47, "Brake Fluid
Level Switch System
Inspection"
ENGINE SIGNAL 1
[C1130]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
BRC-39, "
Engine Sys-
tem Inspection"
ENGINE SIGNAL 2
[C1131]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ENGINE SIGNAL 3
[C1132]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ENGINE SIGNAL 4
[C1133]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ENGINE SIGNAL 6
[C1136]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ACTUATOR RLY
[C1140]ABS actuator relay or circuit malfunction.BRC-44, "
Actuator
Motor, Motor Relay, and
Circuit Inspection"
PRESS SEN CIRCUIT
[C1142]ABS pressure sensor circuit malfunction.BRC-51, "Pressure Sen-
sor System Inspection"
VARIANT CODING
[C1170]V coding is not malfunctioning.BRC-40, "ABS/TCS/
VDC Control Unit
Inspection"
ACTIVE BOOSTER SOLENOID
NG
[C1178]Active booster solenoid is malfunctioning, or signal line of active
booster servo is open or shorted.BRC-48, "Active Booster
System Inspection"
DELTA S SEN NG
[C1179]Delta stroke sensor malfunctioning, or signal line of delta stroke
sensor is open or shorted.BRC-49, "Delta Stroke
Sensor System Inspec-
tion"
ACTIVE BOOSTER RESPONSE
NG
[C1181]Active booster response is malfunctioning, or signal line of active
booster response is open or shorted.
BRC-48, "
Active Booster
System Inspection"BRAKE RELEASE SW NG
[C1184]Brake release switch is malfunctioning, or signal line of brake
release switch is open or shorted.
ACC CU INTERNAL NG
[C1185]ICC control unit circuit malfunction.BRC-54, "
ICC System
Inspection"
BRAKE BOOSTER DEFECT
[C1189]Brake booster is defective or malfunctioning.BRC-48, "Active Booster
System Inspection"
Self-diagnostic item Malfunction detecting condition Check system

TROUBLE DIAGNOSIS
BRC-35
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
×: Applicable
–: Not applicableVDC SIGNAL
(ON/OFF)––×VDC operation (ON/OFF) status is
displayed.
EBD WARN LAMP – –×Brake warning lamp (ON/OFF) sta-
tus is displayed.
SLCT LVR POSI×××Shift position judged by PNP switch
signal.
R POSI SIG – –×Shift position judged by PNP switch
signal.
4WD FAIL REQ – –×The state of 4WD controller is dis-
played by CAN communication sig-
nal.
2WD/4WD – –×It recognizes on software whether it
is 2WD and whether it is in 4WD
state.
BST OPER SIG – –×Active booster operation (ON/OFF)
status is displayed.
PRESS SENSOR×–×Brake pressure detected by pres-
sure sensor is displayed.
CRANKING SIG – –×The input state of the key SW
START position signal is displayed.
PRESS SEN 2 – –×Brake pressure detected by pres-
sure sensor is displayed.
DELTA S SEN – –×The amount of stroke sensor move-
ments in the active booster
detected by DELTA S SEN is dis-
played.
RELEASE SW NO – –×Release switch signal (ON/OFF)
status is displayed. "ON" indicates
that the brake pedal is depressed.
"OFF" is that the brake pedal is
released.
RELEASE SW NC – –×Release switch signal (ON/OFF)
status is displayed. "OFF" indi-
cates that the brake pedal is
depressed on. "ON" is that the
brake pedal is released.
OHB FAIL – –×OHB fail status is displayed.
HBA FAIL – –×HBA fail status is displayed.
OHB SIG – –×OHB operation (ON/OFF) status is
displayed.
HBA SIG – –×HBA operation (ON/OFF) status is
displayed.
PRES CTRL ACC – –×Pressure control state (ON/OFF) is
displayed. It is applied only to an
ICC vehicle.
PRES FAIL ACC – –×Pressure control fail state (ON/
OFF) is displayed. It is applied only
to an ICC vehicle.
STP OFF RLY – –×Stop lamp relay signal (ON/OFF)
status is displayed. Item
(Unit)Data monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELECTION
FROM MENU

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-49
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
3. ACTIVE BOOSTER CIRCUIT INSPECTION
1. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and
active booster connector E49.
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. ACTIVE BOOSTER SENSOR INSPECTION
1. Reconnect the active booster and ABS actuator and electric unit (control unit) connectors.
2. Use "DATA MONITOR" to check if the status of "RELEASE SW NO" and "RELEASE SW NC" is normal.
OK or NG
OK >> Inspection End.
NG >> Replace active booster.
Delta Stroke Sensor System InspectionEFS003R9
INSPECTION PROCEDURE
1. DISPLAY SELF DIAGNOSIS RESULTS
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> GO TO 2.
NO >> Inspection End.ABS actuator and electric unit
(control unit) connector E125Active booster connector
E49Continuity
17 (W/R) 3 (W/R)
Ye s 27 (L/B) 1 (L/B)
28 (Y/B) 5 (Y/B)
30 (LG/R) 2 (LG/R)
31 (W/G) 4 (W/G)
ABS actuator and electric unit
(control unit) connector E125Body ground Continuity
17 (W/R)
—No 27 (L/B)
28 (Y/B)
30 (LG/R)
31 (W/G)
ConditionData monitor display
RELEASE SW NO RELEASE SW NC
When brake pedal is depressed ON OFF
When brake pedal is released OFF ON
Self-diagnosis results
DELTA S SEN NG

BRC-50
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
2. CONNECTOR INSPECTION
1. Turn the ignition switch OFF.
2. Disconnect the delta stroke sensor connector E114 and ABS actuator and electric unit (control unit) con-
nector E125 and inspect the terminals for deformation, disconnection, looseness, or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair connector.
3. DELTA STROKE SENSOR CIRCUIT INSPECTION
1. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and delta
stroke sensor connector E114.
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. DELTA STROKE SENSOR INSPECTION
1. Reconnect the delta stroke sensor and ABS actuator and electric unit (control unit) connectors.
2. Use "DATA MONITOR" to check if the status of "DELTA S SEN" is normal.
OK or NG
OK >> Inspection End.
NG >> Replace delta stroke sensor.ABS actuator and electric unit
(control unit) connector E125Delta stroke sensor
connector E114Continuity
26 (W/V) 1 (W/V)
Yes 39 (G/B) 3 (G/B)
40 (R/Y) 5 (R/Y)
ABS actuator and electric unit
(control unit) connector E125Body ground Continuity
26 (W/V)
—No 39 (G/B)
40 (R/Y)
ConditionData monitor display (Approx.)
DELTA S SEN
When brake pedal is released 0.00 mm (+0.6/-0.4)
When brake pedal is depressed 1.05–1.80 mm

BRC-52
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
4. FRONT PRESSURE SENSOR INSPECTION
1. Reconnect the front pressure sensor and ABS actuator and electric unit (control unit) connectors.
2. Use "DATA MONITOR" to check if the status of "PRESS SENSOR" is normal.
OK or NG
OK >> Inspection End.
NG >> Replace pressure sensor.
REAR PRESSURE INSPECTION PROCEDURE
1. DISPLAY SELF DIAGNOSIS RESULTS
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> GO TO 2.
NO >> Inspection End.
2. CONNECTOR INSPECTION
1. Turn the ignition switch OFF.
2. Disconnect the rear pressure sensor connector E32 and ABS actuator and electric unit (control unit) con-
nector E125 and inspect the terminals for deformation, disconnection, looseness, or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair connector.
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.ConditionData monitor display (Approx.)
PRESS SENSOR
When brake pedal is depressed Positive value
When brake pedal is released 0 bar
Self-diagnosis results
PRESS SEN CIRCUIT
ABS actuator and electric unit
(control unit) connector E125Rear pressure sensor con-
nector E32Continuity
21 (R/G) 1 (R/G)
Ye s 22 (W/L) 3 (W/L)
23 (W/O) 2 (W/O)
ABS actuator and electric unit
(control unit) connector E125Body ground Continuity
21 (R/G)
—No 22 (W/L)
23 (W/O)

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-53
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
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 InspectionEFS0062X
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" .
3. INDICATOR LAMP CHECK
Check that VDC OFF indicator lamp is off.
OK or NG
OK >> GO TO 4.
NG >> Perform basic inspection. Refer to BRC-23, "
Basic Inspection" .
4. CHECK SELF-DIAGNOSTIC RESULTS
Perform ABS actuator and electric unit (control unit) self-diagnosis.
NOTE:
When self-diagnostic results show items other than those above, perform repair or replacement for the item
indicated and repeat self-diagnosis.
Is the above displayed on self-diagnosis display?
YES >> Erase error memory.
NO >> Inspection End.ConditionData monitor display (Approx.)
PRESS SEN 2
When brake pedal is depressed Positive value
When brake pedal is released 0 bar
Self-diagnosis results
ST ANGL SEN SAFE

TROUBLE DIAGNOSES FOR SYMPTOMS
BRC-57
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
TROUBLE DIAGNOSES FOR SYMPTOMSPFP:99999
ABS Works FrequentlyEFS0044T
1. CHECK WARNING LAMP ACTIVATION
Make sure warning lamp remains off while driving.
OK or NG
OK >> GO TO 2.
NG >> Carry out self-diagnosis. Refer to BRC-29, "
SELF-DIAGNOSIS" .
2. CHECK WHEEL SENSORS
Check the following.

Wheel sensor mounting for looseness

Wheel sensors for physical damage

Wheel sensor connectors for terminal damage or loose connections
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
3. CHECK FRONT AND REAR AXLES
Check front and rear axles for excessive looseness. Refer to FAX-5, "
WHEEL HUB" or RAX-5, "WHEEL
HUB" .
OK or NG
OK >> GO TO 4.
NG >> Repair as necessary.
4. CHECK BRAKE FLUID PRESSURE
Check brake fluid pressure distribution.
Refer to BRC-23, "
Basic Inspection" .
Is brake fluid pressure distribution normal?
YES >> Inspection End.
NO >> Perform Basic Inspection. Refer to BRC-23, "
Basic Inspection" .

BRC-58
[VDC/TCS/ABS]
TROUBLE DIAGNOSES FOR SYMPTOMS
Revision: August 20072004 QX56
Unexpected Pedal ActionEFS0044U
1. CHECK WARNING LAMP ACTIVATION
Make sure warning lamp remains off while driving.
OK or NG
OK >> GO TO 2.
NG >> Carry out self-diagnosis. Refer to BRC-29, "
SELF-DIAGNOSIS" .
2. CHECK BRAKE PEDAL STROKE
Check brake pedal stroke.
Is pedal stroke excessive?
YES >> Perform Basic Inspection. Refer to BRC-23, "Basic
Inspection" .
NO >> GO TO 3.
3. CHECK CONNECTOR AND BRAKING PERFORMANCE
1. Disable ABS by disconnecting ABS actuator and electric unit (control unit) connector.
2. Drive vehicle and check brake operation.
NOTE:
Stopping distance may be longer than vehicles without ABS when road condition is slippery.
NOTE:
Driving the vehicle with the ABS actuator and electric unit (control unit) disconnected may induce DTCs in
electrical control units using CAN communication. After the inspection, clear all DTCs. Refer to BRC-10,
"CAN COMMUNICATION" .
OK or NG
OK >> GO TO 4.
NG >> Perform Basic Inspection. Refer to BRC-23, "
Basic Inspection" .
4. CHECK WHEEL SENSORS
Check the following.

Wheel sensor mounting for looseness

Wheel sensors for physical damage

Wheel sensor connectors for terminal damage or loose connections
OK or NG
OK >> Check ABS actuator and electric unit (control unit) connector terminals for deformation, discon-
nection, looseness or damage. Reconnect ABS actuator and electric unit (control unit) harness
connector. Then retest.
NG >> Repair or replace as necessary.
SBR5 40 A