2004 INFINITI QX56 air condition

REAR DISC BRAKE
BR-29
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Revision: August 20072004 QX56
3. Install brake hose to cylinder body and tighten union bolt to specification as necessary. Refer to BR-27,
"Components" .
CAUTION:

Do not reuse copper washers.

Securely attach brake hose to protrusion on cylinder body.
4. Refill with new brake fluid and bleed air as necessary. Refer to BR-11, "
Bleeding Brake System" .
5. Install tires to the vehicle. Refer to WT-6, "
Rotation"
Disassembly and Assembly of Brake Caliper AssemblyEFS003PW
DISASSEMBLY
1. Remove pads from cylinder body.
2. Remove sliding sleeve and boot from cylinder body body.
3. Place a wooden block as shown in the figure, and blow air from
union bolt mounting hole to remove piston and piston boot.
CAUTION:
Do not get your fingers caught in piston.
4. Using a flat-bladed screwdriver, remove piston seal from cylin-
der body.
CAUTION:
Be careful not to damage cylinder body inner wall.
CALIPER INSPECTION
Cylinder Body
CAUTION:

Use new brake fluid to clean. Do not use mineral oils such as gasoline or kerosene.

Check inside surface of cylinder body for score, rust wear, damage or foreign materials. If any of
the above conditions are observed, replace cylinder body.

Minor damage from rust or foreign materials may be eliminated by polishing surface with a fine
emery paper. Replace cylinder body if necessary.
Torque Member
Check for wear, cracks, and damage. If damage or deformation is present, replace the affected part.
Piston
CAUTION:

Piston sliding surface is plated, do not polish with emery paper even if rust of foreign materials
are stuck to sliding surface.

Check piston for score, rust, wear, damage or presence of foreign materials. Replace if any of the
above conditions are observed.
Sliding Pin Bolts and Sliding Pin Boots
Make sure there is no wear, damage, or cracks in sliding sleeve and sliding sleeve boots, and if there are,
replace them.
BRD0041D
PFIA0269E

TROUBLE DIAGNOSIS
BRC-11
[VDC/TCS/ABS]
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TROUBLE DIAGNOSISPFP:00000
How to Perform Trouble Diagnoses for Quick and Accurate RepairEFS003QQ
INTRODUCTION
The ABS/TCS/VDC system has an electronic control unit to control
major functions. The control unit accepts input signals from sensors
and controls actuator operation. It is also important to check for con-
ventional problems such as air leaks in the booster or lines, lack of
brake fluid, or other problems with the brake system.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electrical connections or faulty wiring. In this case,
careful checking of suspicious circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the problem, so a road
test should be performed.
Before undertaking actual checks, take just a few minutes to talk with
a customer who approaches with an ABS/TCS/VDC complaint. The
customer is a very good source of information on such problems,
especially intermittent ones. Through the talks with the customer,
find out what symptoms are present and under what conditions they
occur.
Start your diagnosis by looking for “conventional” problems first. This
is one of the best ways to troubleshoot brake problems on an ABS/
TCS/VDC equipped vehicle. Also check related Service Bulletins for
information.
SEF 2 33 G
SEF 2 34 G

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-41
[VDC/TCS/ABS]
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3. CHECK STEERING ANGLE SENSOR HARNESS
1. Check CAN communication system. Refer to LAN-5, "
CAN COMMUNICATION" .
2. Turn ignition switch OFF and disconnect steering angle sensor
connector M47 and ABS actuator and electric unit (control unit)
connector E125.
3. Check continuity between ABS actuator and electric unit (control
unit) connector E125 and steering angle sensor connector M47.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness.
4. CHECK DATA MONITOR
1. Connect steering angle sensor and ABS actuator and electric unit (control unit) connectors.
2. Use “DATA MONITOR” to check if the status of "STR ANGLE SIG" is normal.
OK or NG
OK >> Perform ABS actuator and electric unit (control unit) self-diagnosis again.
NG >> Replace spiral cable (steering angle sensor) and adjust neutral position of steering angle sensor.
Refer to BRC-62, "
Adjustment of Steering Angle Sensor Neutral Position" .
Yaw Rate/Side/Decel G Sensor System InspectionEFS003R2
CAUTION:
Sudden turns (such as spin turns, acceleration turns), drifting, etc. when VDC function is OFF may
cause the yaw rate/side/decel G sensor system to indicate a problem. This is not a problem if normal
operation can be resumed after restarting the engine.
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
CAUTION:
If vehicle is on turn table at entrance to parking garage, or on other moving surface, VDC OFF indica-
tor lamp may illuminate and CONSULT-II self-diagnosis may indicate yaw rate sensor system malfunc-ABS actuator and
electric unit (control
unit) harness connec-
tor E125Steering angle
sensor
harness connec-
tor M47Continuity
11 ( W ) 3 (W ) Yes
15 (R) 4 (R) Yes
WFIA0224E
Steering condition Data monitor
Straight-ahead –3.5 deg to +3.5 deg
Turn wheel to the right by 90°Approx. - 90deg
Turn wheel to the left by 90°Approx. + 90deg
Self-diagnosis results
YAW R AT E S E N S O R
SIDE G-SEN CIRCUIT
G-SENSOR

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-49
[VDC/TCS/ABS]
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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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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

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