INFINITI QX56 2004 Factory Service Manual

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

TROUBLE DIAGNOSES FOR SYMPTOMS
BRC-59
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
Long Stopping DistanceEFS0044V
1. CHECK BASE BRAKING SYSTEM 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.
OK or NG
OK >> Go to BRC-57, "ABS Works Frequently" .
NG >> Perform Basic Inspection. Refer to BRC-23, "
Basic Inspection" .
ABS Does Not WorkEFS0044W
CAUTION:
The ABS does not operate when the vehicle speed is 10 km/h (6 MPH) or less.
1. CHECK WARNING LAMP ACTIVATION
Turn ignition switch ON and check for warning lamp activation.

Warning lamp should activate for approximately 1 second after turning the ignition switch ON.
OK or NG
OK >> Carry out self-diagnosis. Refer to BRC-29, "SELF-DIAGNOSIS" .
NG >> Go to BRC-60, "
ABS Warning Lamp Does Not Come On When Ignition Switch Is Turned On" .
Pedal Vibration or ABS Operation NoiseEFS0044X
NOTE:
During ABS activation, pedal vibration may be felt and a noise may be heard. This is normal and does not indi-
cate a malfunction.
1. CHECK SYMPTOM
1. Apply brake.
2. Start engine.
Does the symptom occur only when engine is started?
YES >> Carry out self-diagnosis. Refer to BRC-29, "SELF-DIAGNOSIS" .
NO >> GO TO 2.
2. RECHECK SYMPTOM
Does the symptom occur only when electrical equipment switches (such as headlamps) are turned on?
YES >> Check for radio, antenna or related wiring that is routed too close to the ABS actuator and electric
unit (control unit) and reroute as necessary.
NO >> Go to BRC-57, "
ABS Works Frequently" .

BRC-60
[VDC/TCS/ABS]
TROUBLE DIAGNOSES FOR SYMPTOMS
Revision: August 20072004 QX56
ABS Warning Lamp Does Not Come On When Ignition Switch Is Turned OnEFS0044Y
1. CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) FUSES
Check 30A fusible link h and 40A fusible link i for ABS actuator and electric unit (control unit). For fusible
link layout, refer to PG-4, "
POWER SUPPLY ROUTING CIRCUIT" .
OK or NG
OK >> GO TO 2.
NG >> If fusible link is blown, be sure to eliminate cause of problem before replacing.
2. CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) POWER SUPPLY CIRCUITS
1. Disconnect ABS actuator and electric unit (control unit) connec-
tor.
2. Check voltage between ABS actuator and electric unit (control
unit) connector terminal 1 (Y) and ground and terminal 32 (B/Y)
and ground.
Does battery voltage exist?
YES >> GO TO 3.
NO >> Repair harness or connectors between fusible link and
ABS actuator and electric unit (control unit).
3. CHECK ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) GROUND CIRCUIT
Check continuity between ABS actuator and electric unit (control
unit) connector terminal 16 (B) and ground and terminal 47 (B) and
ground.
Does continuity exist?
YES >> Replace ABS actuator and electric unit (control unit).
Refer to BRC-66, "
Removal and Installation" .
NO >> Repair harness or connectors between ABS actuator
and electric unit (control unit) and ground.
ABS Warning Lamp Stays On When Ignition Switch Is Turned OnEFS0044Z
1. CARRY OUT SELF-DIAGNOSIS
Carry out self-diagnosis. Refer to BRC-29, "
SELF-DIAGNOSIS" .
Are malfunctions detected in self-diagnosis?
YES >> Refer to BRC-30, "Display Item List" .
NO >> Refer to DI-31, "
WARNING LAMPS" .
WFIA0199E
WFIA0196E

TROUBLE DIAGNOSES FOR SYMPTOMS
BRC-61
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
Vehicle Jerks During TCS/VDC ActivationEFS00450
1. ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT) SELF-DIAGNOSIS
Perform ABS actuator and electric unit (control unit) self-diagnosis.
Are self-diagnosis result items displayed?
YES >> After checking and repairing the applicable item, perform the ABS actuator and electric unit (con-
trol unit) self-diagnosis again.
NO >> GO TO 2.
2. ENGINE SPEED SIGNAL INSPECTION
Perform data monitor with CONSULT-II for the ABS actuator and electric unit (control unit).
Is the engine speed at idle 400 rpm or higher?
YES >> GO TO 4.
NO >> GO TO 3.
3. ECM SELF-DIAGNOSIS
Perform ECM self-diagnosis.
Are self-diagnosis result items displayed?
YES >> After checking and repairing the applicable item, perform the ECM self-diagnosis again.
NO >> GO TO 4.
4. TCM SELF-DIAGNOSIS
Perform TCM self-diagnosis.
Are self-diagnosis result items displayed?
YES >> After checking and repairing the applicable item, perform the TCM self-diagnosis again.
NO >> GO TO 5.
5. CONNECTOR INSPECTION
Disconnect the ABS actuator and electric unit (control unit) connector and the ECM connectors and check the
terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 6.
NG >> Repair or replace as necessary.
6. CAN COMMUNICATION INSPECTION
Check the CAN communication system. Refer to BRC-54, "
CAN Communication System Inspection" .
OK or NG
OK >> Inspection End.
NG >> Refer to LAN-5, "
CAN COMMUNICATION" .

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

ON-VEHICLE SERVICE
BRC-63
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
4. Touch "START".
CAUTION:
Set vehicle as shown in the display.
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.
CAUTION:
Be sure to carry out above operation
7. Run vehicle with front wheels in straight-ahead position, then
stop.
8. Select "DATA MONITOR", "SELECTION FROM MENU", and
"DECEL G SEN" on CONSULT-II screen. Then check that "DECEL G SEN" is within ±0.08G. If value is
more than specification, repeat steps 3 to 7.
9. Erase memory of ABS actuator and electric unit (control unit) and ECM.
10. Turn ignition switch to OFF.
SF IA116 2E

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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BRC
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).

BRC-66
[VDC/TCS/ABS]
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)
Revision: August 20072004 QX56
ACTUATOR AND ELECTRIC UNIT (ASSEMBLY)PFP:47660
Removal and InstallationEFS003RQ
REMOVAL
1. Disconnect the negative battery terminal.
2. Remove the cowl top extension. Refer to EI-18, "
Removal and Installation" .
3. Drain the brake fluid. Refer to BR-10, "
Drain and Refill" .
4. Disconnect the actuator harness from the ABS actuator and electric unit (control unit).
CAUTION:

To remove the brake tubes, use a flare nut wrench to prevent the flare nuts and brake tubes from
being damaged.

Be careful not to splash brake fluid on painted areas.
5. Disconnect the brake tubes.
6. Remove the three bolts and remove the ABS actuator and electric unit (control unit).
WFIA0241E
1. To rear left 2. To rear right 3. To front left
4. To front right 5. From the master cylinder secondary side 6. From the master cylinder primary side
7. ABS actuator and electric unit (control
unit)8. Harness connector

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" .