sensor INFINITI QX56 2004 Factory Service Manual

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-51
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
Pressure Sensor System InspectionEF S0 03 RA
FRONT 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 front pressure sensor connector E31 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. FRONT PRESSURE SENSOR CIRCUIT INSPECTION
1. Measure the continuity between the ABS actuator and electric unit (control unit) harness connector E125
and front pressure sensor harness connector E31.
2. Measure the continuity between the ABS actuator and electric unit (control unit) harness connector E125
and body ground.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness or connector.
Self-diagnosis results
PRESS SEN CIRCUIT
ABS actuator and electric unit
(control unit) harness connector
E125Front pressure sensor har-
ness connector E31 Continuity
18 (LG) 3 (LG)
Yes 19 (SB) 1 (SB)
20 (R/L) 2 (R/L)
ABS actuator and electric unit
(control unit) harness connector
E125Body ground Continuity
18 (LG)
—No 19 (SB)
20 (R/L)

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 DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-55
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
Inspection For Self-diagnosis Result "ST ANGLE SEN SIGNAL"EFS003RC
INSPECTION PROCEDURE
1. PERFORM SELF-DIAGNOSIS
Perform ABS actuator and electric unit (control unit) self-diagnosis.
Do self-diagnosis results indicate anything other than shown above?
Yes >> Perform repair or replacement for the item indicated.
No >> Perform adjustment of steering angle sensor neutral position. GO TO 2.
2. PERFORM SELF-DIAGNOSIS AGAIN
1. Turn the ignition switch to OFF and then to ON to erase self-diagnosis results.
2. Perform ABS actuator and electric unit (control unit) self-diagnosis again.
Are any self-diagnosis results displayed?
Yes >> Replace steering angle sensor. Refer to BRC-68, "Removal and Installation" .
No >> Inspection End.
Inspection For Self-diagnosis Result "DECEL G SEN SET"EFS003RD
INSPECTION PROCEDURE
1. PERFORM SELF-DIAGNOSIS
Perform ABS actuator and electric unit (control unit) self-diagnosis.
Do self-diagnosis results indicate anything other than shown above?
Yes >> Perform repair or replacement for the item indicated.
No >> Perform adjustment of decel G sensor neutral position. GO TO 2.
2. PERFORM SELF-DIAGNOSIS AGAIN
1. Turn the ignition switch to OFF and then to ON to erase self-diagnosis results.
2. Perform ABS actuator and electric unit (control unit) self-diagnosis again.
Are any self-diagnosis results displayed?
Yes >> Replace decel G sensor. Refer to BRC-69, "Removal and Installation" .
No >> Inspection End.
VDC OFF Indicator lamp Does Not IlluminateEF S0 03 RE
INSPECTION PROCEDURE
1. CHECK VDC OFF INDICATOR LAMP
Disconnect ABS actuator and electric unit (control unit) connector E125.
Do the ABS warning lamp and VDC OFF indicator lamp illuminate?
Yes >> Replace combination meter.
No >> Replace ABS actuator and electric unit (control unit).
2. PERFORM SELF-DIAGNOSIS AGAIN
1. Turn the ignition switch to OFF and then to ON to erase self-diagnosis results.
2. Perform ABS actuator and electric unit (control unit) self-diagnosis again.
Are any self-diagnosis results displayed?
Yes >> Replace decel G sensor. Refer to BRC-69, "Removal and Installation" .
No >> Inspection End.Self-diagnosis results : ST ANGLE SEN SIGNAL
Self-diagnosis results : DECEL G SEN SET

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

BRC-62
[VDC/TCS/ABS]
ON-VEHICLE SERVICE
Revision: August 20072004 QX56
ON-VEHICLE SERVICEPFP:00000
Adjustment of Steering Angle Sensor Neutral PositionEFS003RM
After removing/installing or replacing ABS actuator and electric unit (control unit), steering angle sensor, steer-
ing and suspension components which affect wheel alignment or after adjusting wheel alignment, be sure to
adjust neutral position of steering angle sensor before running vehicle.
NOTE:
Adjustment of steering angle sensor neutral position requires CONSULT-II.
1. Stop vehicle with front wheels in straight-ahead position.
2. Connect CONSULT-II to data link connector on vehicle, and turn
ignition switch ON (do not start engine).
3. Touch “ABS”, “WORK SUPPORT” and “ST ANGLE SENSOR
ADJUSTMENT” on CONSULT-II screen in this order.
4. Touch “START”.
CAUTION:
Do not touch steering wheel while adjusting steering angle
sensor.
5. After approximately 10 seconds, touch “END”. (After approxi-
mately 60 seconds, it ends automatically.)
6. Turn ignition switch OFF, then turn it ON again.
7. Run vehicle with front wheels in straight-ahead position, then
stop.
8. Select “DATA MONITOR”, “SELECTION FROM MENU”, and
“STR ANGLE SIG” on CONSULT-II screen. Then check that
“STR ANGLE SIG” is within 0±3.5 deg. If value is more than specification, repeat steps 1 to 5.
9. Erase memory of ABS actuator and electric unit (control unit) and ECM.
10. Turn ignition switch to OFF.
Calibration of Decel G SensorEFS003RN
After removing/installing or replacing ABS actuator and electric unit (control unit), yaw rate/side/decel G sen-
sor, steering and suspension components which affect wheel alignment or after adjusting wheel alignment, be
sure to calibrate the decel G sensor before running vehicle.
NOTE:
Calibration of decel G sensor requires CONSULT-II.
1. Stop vehicle with front wheels in straight-ahead position.
CAUTION:

The work should be done on a level area with an unloaded vehicle.

Keep all the tires inflated to the correct pressures. Adjust the tire pressure to the specified pres-
sure value.
2. Connect CONSULT-II with CONSULT-II CONVERTER to data link connector on vehicle, and turn ignition
switch ON (do not start engine).
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carries out CAN communication.
3. Touch "ABS", "WORK SUPPORT" and "DECEL G SEN CALIBRATION" on CONSULT-II screen in this
order. Refer to BRC-28, "
CONSULT-II BASIC OPERATION PROCEDURE" .
BBIA0369E
WFIA0239E

BRC-64
[VDC/TCS/ABS]
WHEEL SENSORS
Revision: August 20072004 QX56
WHEEL SENSORSPFP:47910
Removal and InstallationEFS003RO
REMOVAL
1. Remove wheel sensor mounting screw.

When removing the front wheel sensor, first remove the disc rotor to gain access to the front wheel sen-
sor mounting bolt. Refer to BR-22, "
Removal and Installation of Brake Caliper and Disc Rotor" .

When removing the rear wheel sensor, first remove the rear hub and bearing assembly to gain access
to the rear wheel sensor mounting bolt. Refer to RAX-5, "
Removal and Installation" .
2. Pull out the sensor, being careful to turn it as little as possible.
CAUTION:

Do not pull on the sensor harness.
3. Disconnect wheel sensor harness electrical connector, then remove harness from mounts.
INSTALLATION
Installation is in the reverse order of removal. Tighten wheel sensor bolt to the specified torque.
CAUTION:
Installation should be performed while paying attention to the following.

Inspect wheel sensor O-ring, replace sensor assembly if damaged.

Before installing wheel sensor, make sure no foreign materials (such as iron fragments) are
adhered to the pick-up part of the sensor, to the inside of the sensor mounting hole or on the rotor
mounting surface.

Apply a coat of suitable grease to the wheel sensor O-ring and mounting hole.
WFIA0240E

SENSOR ROTOR
BRC-65
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
SENSOR ROTORPFP:47970
Removal and Installation EF S0 03 RP
NOTE:
The wheel sensor rotors are built into the wheel hubs and are not removable. If damaged, replace wheel hub
and bearing assembly. Refer to FAX-5, "
Removal and Installation" (Front), RAX-5, "Removal and Installation"
(Rear).

ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)
BRC-67
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
To install, use a flare nut wrench (commercial service tool).

Always tighten brake tubes to specification when installing. Refer to BR-12, "BRAKE PIPING AND
HOSE" .

Never reuse drained brake fluid.

After installation of the ABS actuator and electric unit (control unit), refill brake system with new
brake fluid. Then bleed the air from the system. Refer to BR-11, "
Bleeding Brake System" .

After installation of ABS actuator, adjust steering angle sensor. Refer to BRC-62, "Adjustment of
Steering Angle Sensor Neutral Position" .

After installation of ABS actuator, calibrate the decel G sensor. Refer to BRC-62, "Calibration of
Decel G Sensor" .