ignition INFINITI QX56 2004 Factory Service Manual

TROUBLE DIAGNOSIS
BRC-25
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
MA
B
BRC
Revision: August 20072004 QX56
STR ANGLE SIGSteering angle
detected by steering
angle sensorStraight-ahead Approx. 0 deg
BRC-40, "Steering Angle
Sensor System"Steering wheel turned –756 to 756 deg
YAW R AT E S E NYaw rate detected by
yaw rate sensorVehicle stopped Approx. 0 d/sBRC-41, "
Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running –100 to 100 d/s
SIDE G SENSORTransverse G detected
by side G-sensorVehicle stopped
Approx. 0 m/s
2BRC-41, "Yaw Rate/Side/
Decel G Sensor System
Inspection"Vehicle running
–16.7 to 16.7 m/s2
BATTERY VOLTBattery voltage sup-
plied to ABS actuator
and electric unit (con-
trol unit)Ignition switch ON 10 to 16VBRC-46, "
ABS/TCS/VDC
Control Unit Power and
Ground Systems Inspec-
tion"
STOP LAMP SWStop lamp switch oper-
ationBrake pedal depressed ONBRC-45, "
Stop Lamp
Switch System Inspec-
tion"Brake pedal not depressed OFF
OFF SWVDC OFF switch
ON/OFF status VDC OFF switch ON
(When VDC OFF indicator
lamp is ON)ON
BRC-56, "
VDC OFF
SWITCH"VDC OFF switch OFF
(When VDC OFF indicator
lamp is OFF)OFF
ABS WARN LAMPABS warning lamp ON
condition (Note 2)ABS warning lamp ON ON
—
ABS warning lamp OFF OFF
MOTOR RELAYOperation status of
motor and motor relayIgnition switch ON or running
(ABS not activated)OFF
BRC-44, "
Actuator Motor,
Motor Relay, and Circuit
Inspection"Ignition switch ON or engine
running (ABS activated)ON
ACTUATOR RLYActuator relay opera-
tion statusVehicle stopped (Ignition
switch ON)OFF
BRC-44, "
Actuator Motor,
Motor Relay, and Circuit
Inspection"Vehicle stopped (Engine run-
ning)ON
OFF LAMPVDC OFF indicator
lamp status (Note 3) When VDC OFF indicator
lamp is ONON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"When VDC OFF indicator
lamp is OFFOFF
SLIP LAMPSLIP indicator lamp
status (Note 4)When SLIP indicator lamp is
ONON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"When SLIP indicator lamp is
OFFOFF Monitor item Display contentData monitor
Note: Error inspection
checklist
ConditionReference value in
normal operation

BRC-26
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Note 1: Confirm tire pressure is normal.
Note 2: ON/OFF timing of ABS warning lamp
ON: For approximately 2 seconds after ignition switch is turned ON, or when a malfunction is detected.
OFF: Approximately 2 seconds after ignition switch is turned ON (when system is in normal operation) and TCS/VDC function is not
activated.
Note 3: ON/OFF timing of VDC OFF indicator lamp
ON: For approximately 2 seconds after ignition switch is turned ON, or when a malfunction is detected and VDC OFF switch is ON.
OFF: Approximately 2 seconds after ignition switch is turned ON (when system is in normal operation.) And when VDC OFF switch is
OFF.
Note 4: SLIP indicator lamp ON/OFF timing
ON: For approximately 2 seconds after ignition switch is turned ON, or when a malfunction is detected and TCS/VDC function is acti-
vated while driving.FR LH IN SOL
FR LH OUT SOL
FR RH IN SOL
FR RH OUT SOL
RR RH IN SOL
RR RH OUT SOL
RR LH IN SOL
RR LH OUT SOLSolenoid valve opera-
tionActuator (solenoid) is active
(“ACTIVE TEST” with CON-
SULT-II) or actuator relay is
inactive (in fail-safe mode).ON
BRC-43, "
Solenoid and
VDC Change-Over Valve
System Inspection"
When actuator (solenoid) is
not active and actuator relay is
active (ignition switch ON).OFF
CV1
CV2
SV1
SV2VDC switch-over valve
statusWhen actuator (switch-over
valve) is active (“ACTIVE
TEST” with CONSULT-II) or
actuator relay is inactive (when
in fail-safe mode).ON
When actuator (switch-over
valve) is not active and actua-
tor relay is active (ignition
switch ON).OFF
DECEL G-SENLongitudinal accelera-
tion detected by Decel
G-SensorVehicle stopped Approx. 0 GBRC-41, "
Ya w R a te / S i d e /
Decel G Sensor System
Inspection"Vehicle running -1.7 to 1.7 G
PRESS SENSORBrake fluid pressure
detected by pressure
sensorDo not step on the Brake pedal
(When ignition switch is ON)Approx. 0 bar
—
Step on the Brake pedal
(When ignition switch is ON)-40 to 300 bar
FLUID LEV SWON/OFF status of
brake fluid level switchWhen brake fluid level switch
ONON
DI-31, "
WAR NIN G
LAMPS"When brake fluid level switch
OFF OFF
VDC SIGNAL
TCS SIGNAL
ABS SIGNAL
EBD SIGNALSignal statusVDC active
TCS active
ABS active
EBD activeON
VDC system
TCS system
ABS system
EBD system VDC not active
TCS not active
ABS not active
EBD not activeOFF
VDC FAIL SIG
TCS FAIL SIG
ABS FAIL SIG
EBD FAIL SIGFail signal statusVDC fail
TCS fail
ABS fail
EBD failON
VDC system
TCS system
ABS system
EBD system VDC normal
TCS normal
ABS normal
EBD normalOFF Monitor item Display contentData monitor
Note: Error inspection
checklist
ConditionReference value in
normal operation

TROUBLE DIAGNOSIS
BRC-27
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
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MA
B
BRC
Revision: August 20072004 QX56
OFF: Approximately 2 seconds after ignition switch is turned ON (when system is in normal operation) and TCS/VDC function is not
activated.
Flashing: TCS/VDC function is active during driving

BRC-28
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
CONSULT-II Function (ABS)EFS003QX
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II BASIC OPERATION PROCEDURE
1. Turn ignition switch OFF.
2. Connect CONSULT-II and CONSULT-II CONVERTER to the
data link connector.
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II
CONVERTER, malfunctions might be detected in self-diag-
nosis depending on control unit which carries out CAN
communication.
3. Turn ignition switch ON.
4. Touch “START (NISSAN BASED VHCL)”.
5. Touch “ABS” in the “SELECT SYSTEM” screen.
If “ABS” is not indicated, go to GI-39, "
CONSULT-II Data Link
Connector (DLC) Circuit" .
ABS diagnostic mode Description
WORK SUPPORTSupports inspection and adjustments. Commands are transmitted to the ABS actuator and electric
unit (control unit) for setting the status suitable for required operation, input/output signals are
received from the ABS actuator and electric unit (control unit) and received data is displayed.
SELF-DIAG RESULTS Displays ABS actuator and electric unit (control unit) self-diagnosis results.
DATA MONITOR Displays ABS actuator and electric unit (control unit) input/output data in real time.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.
FUNCTION TESTConducted by CONSULT-II instead of a technician to determine whether each system is "OK" or
"NG".
ECU PART NUMBER ABS actuator and electric unit (control unit) part number can be read.
BBIA0369E
BCIA0029E
BCIA0030E

TROUBLE DIAGNOSIS
BRC-29
[VDC/TCS/ABS]
C
D
E
G
H
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K
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MA
B
BRC
Revision: August 20072004 QX56
6. Select the required diagnostic location from the “SELECT DIAG
MODE” screen.
For further information, see the CONSULT-II Operation Manual.
SELF-DIAGNOSIS
Description
If an error is detected in the system, the ABS warning lamp will turn on. In this case, perform self-diagnosis as
follows:
Operation Procedure
1. Turn ignition switch OFF.
2. Connect CONSULT-II and CONSULT-II CONVERTER to the data link connector.
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. Turn ignition switch ON.
4. Start engine and drive at approximately 30 km/h (19 MPH) or more for approximately 1 minute.
5. After stopping the vehicle, with the engine running, touch “START (NISSAN BASED VHCL)”, “ABS”,
“SELF-DIAG RESULTS” in order on the CONSULT-II screen.
CAUTION:
If “START (NISSAN BASED VHCL)” is touched immediately after starting the engine or turning on
the ignition switch, “ABS” might not be displayed in the Select System screen. In this case, repeat
the operation from step 1.
6. The self-diagnostic results are displayed. (If necessary, the self-diagnostic results can be printed out by
touching “PRINT”.)

When “NO DTC IS DETECTED” is displayed, check the ABS warning lamp, SLIP indicator lamp and
VDC OFF indicator lamp.
7. Conduct the appropriate inspection from the display item list, and repair or replace the malfunctioning
component.
8. Start engine and drive at approximately 30 km/h (19 MPH) or more for approximately 1 minute.
CAUTION:

When a wheel sensor “short-circuit” is detected, if the vehicle is not driven at 30 km/h (19 MPH)
for at least 1 minute, the ABS warning lamp will not turn off even if the malfunction is repaired.
9. Turn ignition switch OFF to prepare for erasing the memory.
10. Start the engine and touch “START (NISSAN BASED VHCL)”, “ABS”, “SELF-DIAG RESULTS”, “ERASE”
in order on the CONSULT-II screen to erase the error memory.
If “ABS” is not indicated, go to GI-39, "
CONSULT-II Data Link Connector (DLC) Circuit" .
CAUTION:
If the error memory is not erased, re-conduct the operation from step 5.
11. For the final inspection, drive at approximately 30 km/h (19 MPH) or more for approximately 1 minute and
confirm that the ABS warning lamp, SLIP indicator lamp, and VDC OFF indicator lamp are off.
BCIA0031E

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-33
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
MA
B
BRC
Revision: August 20072004 QX56
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.
2. Touch “START (NISSAN BASED VHCL)”, “ABS”, “DATA MONITOR” in order on the CONSULT-II screen.
If “ABS” is not indicated, go to GI-39, "
CONSULT-II Data Link Connector (DLC) Circuit" .
CAUTION:
When “START (NISSAN BASED VHCL)” is touched immediately after starting the engine or turning
on the ignition switch, “ABS” might not be displayed in the system selection screen. In this case,
repeat the operation from step 2.
3. Return to the Monitor Item Selection screen, and touch “ECU INPUT SIGNALS”, “MAIN SIGNALS”, or
“SELECTION FROM MENU”. Refer to the following information.
4. When “START” is touched, the data monitor screen is displayed.
Display Item List
Item
(Unit)Data monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELECTION
FROM MENU
GEAR×××Gear position judged by PNP
switch signal is displayed.
FR RH SENSOR
(km/h, MPH)×××Wheel speed calculated by front
RH wheel sensor signal is dis-
played.
FR LH SENSOR
(km/h, MPH)×××Wheel speed calculated by front LH
wheel sensor signal is displayed.
RR RH SENSOR
(km/h, MPH)×××Wheel speed calculated by rear RH
wheel sensor signal is displayed.
RR LH SENSOR
(km/h, MPH)×××Wheel speed calculated by rear LH
wheel sensor signal is displayed.
BATTERY VOLT
(V)×××Voltage supplied to ABS actuator
and electric unit (control unit) is dis-
played.
N POSI SIG – –×Shift position judged by PNP switch
signal.
P POSI SIG – –×Shift position judged by PNP switch
signal.
ACCEL POS SIG
(%)×–×Throttle valve open/close status
judged by CAN communication sig-
nal is displayed.
ENGINE SPEED
(rpm)×××Engine speed judged by CAN com-
munication signal is displayed.
STR ANGLE SIG
(deg)×–×Steering angle detected by steering
angle sensor is displayed.
YA W R AT E S E N
(d/s)×××Yaw rate detected by yaw rate sen-
sor is displayed.
DECEL G SEN
(d/s)×××Longitudinal acceleration detected
by decel G-sensor is displayed.
SIDE G-SENSOR
(m/s
2 )×– ×Transverse acceleration detected
by side G-sensor is displayed.
STOP LAMP SW
(ON/OFF)×××Stop lamp switch (ON/OFF) status
is displayed.
OFF SW
(ON/OFF) ×× ×VDC OFF switch (ON/OFF) status
is displayed.
ABS WARN LAMP
(ON/OFF)–××ABS warning lamp (ON/OFF) status
is displayed.

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-41
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
MA
B
BRC
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

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