Brc INFINITI QX56 2004 Factory Workshop Manual

BRC-40
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
ABS/TCS/VDC Control Unit InspectionEFS003R0
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
Yes >> Replace ABS actuator and electric unit (control unit). Refer to BRC-66, "Removal and Installation"
.
No >> Inspection End.
Steering Angle Sensor SystemEFS003R1
INSPECTION PROCEDURE
1. CHECK SELF-DIAGNOSIS RESULT
Check self-diagnosis results.
Is above displayed in self-diagnosis item?
YES >> GO TO 2.
NO >> Inspection End.
2. CHECK CONNECTOR
1. Disconnect steering angle sensor connector M47 and ABS actuator and electric unit (control unit) connec-
tor E125 and check terminals for deformation, disconnection, looseness, or damage. Repair or replace as
necessary.
2. Reconnect connectors and repeat ABS actuator and electric unit (control unit) self-diagnosis.
IS "ST ANGLE SEN CIRCUIT" or "ST ANG SEN COM CIR" DISPLAYED?
YES >> GO TO 3.
NO >> Inspection End.
Self-diagnosis results
CONTROLLER FAILURE
VARIANT CODING
Self-diagnosis results
ST ANGLE SEN CIRCUIT
ST ANG SEN COM CIR

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-41
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
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

BRC-42
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
tion. However, in this case there is no malfunction in yaw rate sensor system. Take vehicle off of turn
table or other moving surface, and start engine. Results will return to normal.
Is the above displayed in the self-diagnosis display items?
Yes >> GO TO 2.
No >> Inspection End.
2. CONNECTOR INSPECTION
Disconnect the ABS actuator and electric unit (control unit) connector E125 and yaw rate/side/decel G sensor
connector M108.
Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
3. YAW RATE/SIDE/DECEL G SENSOR HARNESS INSPECTION
1. Turn off the ignition switch and disconnect yaw rate/side/decel G sensor connector M108 and ABS actua-
tor and electric unit (control unit) connector E125.
2. Check continuity between the ABS actuator and electric unit (control unit) connector E125 and the yaw
rate/side/decel G sensor connector M108.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace as necessary.
4. YAW RATE/SIDE/DECEL G SENSOR INSPECTION
1. Connect the yaw rate/side/decel G sensor connector M108 and ABS actuator and electric unit (control
unit) connector E125.
2. Use “DATA MONITOR” to check if the yaw rate/side/decel G sensor signals are normal.
OK or NG
OK >> Inspection End.
NG >> Replace the yaw rate/side/decel G sensor. Refer to BRC-69, "
Removal and Installation" . ABS actuator and electric unit
(control unit) harness connector
E125Yaw rate/side/decel G sensor
harness connector M108 Continuity
6 (Y/R) 3 (Y/R) Yes
24 (P) 5 (P) Yes
25 (G/R) 1 (G/R) Yes
29 (G/W) 2 (G/W) Yes
Vehicle statusYaw rate sensor
(Data monitor standard)Side G sensor
(Data monitor standard)Decel G Sensor
(Data monitor standard)
When stopped -4 to +4 deg/s -1.1 to +1.1 m/s -0.11 G to +0.11 G
Right turn Negative value Negative value -
Left turn Positive value Positive value -
Speed up - - Negative value
Speed down - - Positive value

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-43
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
Solenoid and VDC Change-Over Valve System InspectionEFS003R3
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
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. Disconnect ABS actuator and electric unit (control unit) connector E125.
2. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
Self-diagnosis results
FR LH IN ABS SOL
FR LH OUT ABS SOL
RR RH IN ABS SOL
RR RH OUT ABS SOL
FR RH IN ABS SOL
FR RH OUT ABS SOL
RR LH IN ABS SOL
RR LH OUT ABS SOL
CV 1
CV 2
SV 1
SV 2

BRC-44
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
3. CHECKING SOLENOID POWER AND GROUND
1. Check voltage between ABS actuator and electric unit (control
unit) harness connector E125 and body ground.
2. Check resistance between ABS actuator and electric unit (con-
trol unit) harness connector E125 and body ground.
OK or NG
OK >> Perform self-diagnosis again. If the same results
appear, replace ABS actuator and electric unit (control
unit). Refer to BRC-66, "
Removal and Installation" .
NG >> Repair the circuit.
Actuator Motor, Motor Relay, and Circuit InspectionEFS003R4
INSPECTION PROCEDURE
1. CHECKING 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. Disconnect ABS actuator and electric unit (control unit) connector E125.
2. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.ABS actuator and electric
unit (control unit)
connector E125Body
groundMeasured
value
(Approx.)
32 (B/Y) — 12V
WFIA0195E
ABS actuator and electric
unit (control unit)
connector E125Body
groundMeasured
value Ω
(Approx.)
16 (B) — 0 Ω
47 (B) — 0 Ω
WFIA0196E
Self-diagnosis results
PUMP MOTOR
ACTUATOR RLY

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-45
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
3. CHECKING ABS MOTOR AND MOTOR RELAY POWER SYSTEM
1. Check voltage between ABS actuator and electric unit (control
unit) harness connector E125 and body ground.
2. Check resistance between ABS actuator and electric unit (con-
trol unit) connector E125 and body ground.
OK or NG
OK >> Perform self-diagnosis again. If the same results
appear, replace ABS actuator and electric unit (control
unit). Refer to BRC-66, "
Removal and Installation" .
NG >> Repair the circuit.
Stop Lamp Switch System InspectionEFS003R5
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
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. Disconnect the ABS actuator and electric unit (control unit) connector E125 and stop lamp switch connec-
tor E38.
2. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.ABS actuator and electric
unit (control unit)
connector E125Body
groundMeasured
value
(Approx.)
1 (Y) — 12V
WFIA0209E
ABS actuator and electric
unit (control unit)
harness connector E125Body
groundMeasured
value Ω
(Approx.)
16 (B) — 0Ω
47 (B) — 0Ω
WFIA0196E
Self-diagnosis results
STOP LAMP SW

BRC-46
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
3. STOP LAMP SWITCH INSPECTION
Check the voltage between the ABS actuator and electric unit (con-
trol unit) harness connector E125 terminal 41 (R/B) and body
ground.
OK or NG
OK >> Perform self-diagnosis again. If the same results
appear, replace ABS actuator and electric unit (control
unit). Refer to BRC-66, "
Removal and Installation" .
NG >> GO TO 4.
4. STOP LAMP RELAY CIRCUIT INSPECTION
1. Disconnect the stop lamp relay harness connector E12.
2. Check the continuity between the ABS actuator and electric unit
(control unit) harness connector E125 terminal 41 (R/B) and
stop lamp relay harness connector E12 terminal 4 (R/B).
OK or NG
OK >> Perform self-diagnosis again. If the same results
appear, replace ABS actuator and electric unit (control
unit). Refer to BRC-66, "
Removal and Installation" .
NG >> Refer to LT-103, "
STOP LAMP" .
ABS/TCS/VDC Control Unit Power and Ground Systems InspectionEFS003R6
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
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. Disconnect the ABS actuator and electric unit (control unit) connector E125.
2. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.Brake pedal depressed : Battery voltage
(approx. 12V)
Brake pedal not depressed : Approx. 0V
WFIA0198E
Continuity should exist
LFIA0218E
Self-diagnosis results
BATTERY VOLTAGE

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-47
[VDC/TCS/ABS]
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BRC
Revision: August 20072004 QX56
3. ABS/TCS/VDC CONTROL UNIT POWER AND GROUND CIRCUIT INSPECTION
Measure the voltage and continuity between the ABS actuator and electric unit (control unit) harness connec-
tor E125 and body ground.
OK or NG
OK >> Check the battery for loose terminals, low voltage, etc. Repair as necessary.
NG >> Repair the circuit.
Brake Fluid Level Switch System InspectionEFS003R7
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
1. Check the brake reservoir tank fluid level. If the level is low, add brake fluid.
2. Erase the self-diagnosis results and check the self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
Yes >> GO TO 2.
No >> Inspection End.
2. CONNECTOR INSPECTION
1. Disconnect the ABS actuator and electric unit (control unit) connector E125 and brake fluid level switch
connector E21.
2. Check the terminals for deformation, disconnection, looseness or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace as necessary.
3. CHECK THE HARNESS BETWEEN THE BRAKE FLUID LEVEL SWITCH AND THE ABS ACTUATOR
AND ELECTRIC UNIT (CONTROL UNIT)
Check the continuity between the brake fluid level switch harness connector E21 and the ABS actuator and
electric unit (control unit) harness connector E125.
OK or NG
OK >> GO TO 4.
NG >> Repair the circuit.Signal nameABS actuator and electric unit
(control unit)
harness connector E125Body
groundMeasured value
Power supply1 (Y)
— Battery voltage (Approx. 12V)
32 (B/Y)
Ground16 (B)
— Continuity should exist.
47 (B)
Self-diagnosis results
BR FLUID LEVEL LOW
ABS actuator and electric unit
(control unit) harness connector
E125Brake fluid level switch harness
connector E21Continuity
8 (P/B) + (P/B) Yes
8 (P/B) Ground No
Ground - (B) Yes

BRC-48
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: August 20072004 QX56
4. CHECK BRAKE FLUID LEVEL SWITCH
Check continuity between brake fluid level switch terminals + and -.
OK or NG
OK >> Perform self-diagnosis again. If the same results appear, replace ABS actuator and electric unit
(control unit). Refer to BRC-66, "
Removal and Installation" .
NG >> Replace brake fluid level switch.
Active Booster System InspectionEFS003R8
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 active booster connector E49 and ABS actuator and electric unit (control unit) connector
E125 and inspect the terminals for deformation, disconnection, looseness, or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair connector.Continuity should not exist.
Self-diagnosis results
ACTIVE BOOSTER SOLENOID NG
ACTIVE BOOSTER RESPONSE NG
BRAKE RELEASE SWITCH NG
BRAKE BOOSTER DEFECT

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