ECU INFINITI QX56 2010 Factory Service Manual

BRC-3
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C1185 ICC UNIT .................................................77
Description .......................................................... ....77
DTC Logic ...............................................................77
Diagnosis Procedure ...............................................77
Special Repair Requirement ...................................78
U1000 CAN COMM CIRCUIT .............................79
Description .......................................................... ....79
DTC Logic ...............................................................79
Diagnosis Procedure ...............................................79
VDC OFF SWITCH .............................................80
Description .......................................................... ....80
Component Function Check ....................................80
Diagnosis Procedure ...............................................80
Component Inspection ............................................81
Special Repair Requirement ...................................81
ABS WARNING LAMP ................................... ....82
Description .......................................................... ....82
Component Function Check ....................................82
Diagnosis Procedure ...............................................82
Special Repair Requirement ...................................82
BRAKE WARNING LAMP ............................. ....83
Description .......................................................... ....83
Component Function Check ....................................83
Diagnosis Procedure ...............................................83
Special Repair Requirement ...................................83
VDC OFF INDICATOR LAMP ........................ ....84
Description .......................................................... ....84
Component Function Check ....................................84
Diagnosis Procedure ...............................................84
Special Repair Requirement ...................................85
SLIP INDICATOR LAMP ................................ ....86
Description .......................................................... ....86
Component Function Check ....................................86
Diagnosis Procedure ...............................................86
Special Repair Requirement ...................................86
ECU DIAGNOSIS ........... ..............................87
ABS ACTUATOR AND ELECTRIC UNIT
(CONTROL UNIT) .......................................... ....
87
Reference Value ................................................. ....87
Wiring Diagram - BRAKE CONTROL SYSTEM - ....92
Fail-Safe ..................................................................99
DTC No. Index ......................................................100
SYMPTOM DIAGNOSIS ............................102
VDC/TCS/ABS ................................................ ..102
Symptom Table ................................................... ..102
EXCESSIVE ABS FUNCTION OPERATION
FREQUENCY ...................................................
103
Diagnosis Procedure ........................................... ..103
UNEXPECTED PEDAL REACTION ...............104
Diagnosis Procedure .............................................104
THE BRAKING DISTANCE IS LONG .............105
Diagnosis Procedure .............................................105
ABS FUNCTION DOES NOT OPERATE .......106
Diagnosis Procedure .............................................106
PEDAL VIBRATION OR ABS OPERATION
SOUND OCCURS ...........................................
107
Diagnosis Procedure ........................................... ..107
VEHICLE JERKS DURING VDC/TCS/ABS
CONTROL .......................................................
108
Diagnosis Procedure .............................................108
NORMAL OPERATING CONDITION .............109
Description .............................................................109
PRECAUTION ............................................110
PRECAUTIONS ...............................................110
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ..
110
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect .................................
110
Precaution for Brake System .................................111
Precaution for Brake Control .................................111
Precaution for CAN System ...................................112
PREPARATION .........................................113
PREPARATION ...............................................113
Special Service Tool ............................................ ..113
Commercial Service Tool ......................................113
REMOVAL AND INSTALLATION .............114
WHEEL SENSORS .........................................114
Removal and Installation ..................................... ..114
SENSOR ROTOR ............................................115
Removal and Installation .......................................115
ACTUATOR AND ELECTRIC UNIT (ASSEM-
BLY) ................................................................
116
Removal and Installation .......................................116
STEERING ANGLE SENSOR .........................118
Removal and Installation .......................................118
G SENSOR ......................................................119
Removal and Installation .......................................119
Revision: April 20092010 QX56

DIAGNOSIS SYSTEM [ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
BRC-23
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
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DIAGNOSIS SYSTEM [ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
CONSULT-III Function (ABS)INFOID:0000000005147962
FUNCTION
CONSULT-III can display each diagnostic item using the diagnostic test modes shown following.
SELF DIAGNOSTIC RESULT MODE
Operation Procedure
1. Before performing the self-diagnosis, start engine and drive vehicle at 30 km/h (19 MPH) or more for
approximately 1 minute.
How to Erase Self-diagnosis Results
1. After erasing DTC memory, start engine and drive vehicle at 30 km/h (19 MPH) or more for approximately 1 minute as the final inspection, and make sure t hat the ABS warning lamp, VDC OFF indicator lamp,
SLIP indicator lamp and brake warning lamp turn OFF.
CAUTION:
If memory cannot be erased, perform applicable diagnosis.
NOTE:
• When the wheel sensor malfunctions, after inspecting the wheel sensor system, the ABS warning lamp,
VDC OFF indicator lamp, SLIP indicator lamp and brake warning lamp will not turn OFF even when the
system is normal unless the vehicle is driving at approximately 30 km/h (19 MPH) or more for approxi-
mately 1 minute.
• Brake warning lamp will turn ON in case of parking brake operation (when switch is ON) or of brake fluid level switch operation (when brake fluid is insufficient).
• VDC OFF switch should not stay “ON” position.
Display Item List
Refer to BRC-100, "DTC No. Index".
DATA MONITOR MODE
Display Item List
Diagnostic test mode Function
Work support This mode enables a technician to adjust some devices faster and more accurately by following
the indications on CONSULT-III.
Data Monitor Input/Output data in the ABS actuator and electric uni t (control unit) can be read.
Active Test Diagnostic test mode is which CONSULT-III driv
es some actuators apart from the ABS actuator
and electric unit (control unit) and also shifts some parameters in a specified range.
Self Diagnostic Result Self-diagnostic results can be read and erased quickly.
CAN diag support monitor The results of transmit/receive diagnosis of CAN communication can be read.
ECU Identification ABS actuator and electric unit (control unit) part number can be read.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
FR LH SENSOR
(km/h, mph) ×× × Wheel speed (km/h, mph) calculated by front LH
wheel sensor signal is displayed.
FR RH SENSOR
(km/h, mph) ×× ×
Wheel speed (km/h, mph) calculated by front RH
wheel sensor signal is displayed.
RR LH SENSOR
(km/h, mph) ×× × Wheel speed (km/h, mph) calculated by rear LH
wheel sensor signal is displayed.
RR RH SENSOR
(km/h, mph) ×× × Wheel speed (km/h, mph) calculated by rear RH
wheel sensor signal is displayed.
Revision: April 20092010 QX56

BRC-24
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
DECEL G-SEN
(G) ×× × Longitudinal acceleration (G) detected by decel G-
sensor is displayed.
FR RH IN SOL
(On/Off) –
×× Front RH IN ABS solenoid (On/Off) status is dis-
played.
FR RH OUT SOL
(On/Off) –
×× Front RH OUT ABS solenoid (On/Off) status is dis-
played.
FR LH IN SOL
(On/Off) –
×× Front LH IN ABS solenoid (On/Off) status is displayed.
FR LH OUT SOL
(On/Off) –
×× Front LH OUT ABS solenoid (On/Off) status is dis-
played.
RR RH IN SOL
(On/Off) –
×× Rear RH IN ABS solenoid (On/ Off) status is displayed.
RR RH OUT SOL
(On/Off) –
×× Rear RH OUT ABS solenoid (On/Off) status is dis-
played.
RR LH IN SOL
(On/Off) –
×× Rear LH IN ABS solenoid (On/ Off) status is displayed.
RR LH OUT SOL
(On/Off) –
×× Rear LH OUT ABS solenoid (On/Off) status is dis-
played.
EBD WARN LAMP
(On/Off) ––
×Brake warning lamp (On/Off) status is displayed.
STOP LAMP SW
(On/Off) ×× ×
Stop lamp switch (On/Off) status is displayed.
MOTOR RELAY
(On/Off) –
×× ABS motor relay signal (On/Of f) status is displayed.
ACTUATOR RLY
(On/Off) –
×× ABS actuator relay signal (On/ Off) status is displayed.
ABS WARN LAMP
(On/Off) –
×× ABS warning lamp (On/Off) status is displayed.
OFF LAMP
(On/Off) –
×× VDC OFF Lamp (On/Off) status is displayed.
OFF SW
(On/Off) ×× ×
VDC OFF switch (On/Off) status is displayed.
SLIP LAMP
(On/Off) –
×× SLIP indicator lamp (On/Off) status is displayed.
BATTERY VOLT
(V) ×× ×
Voltage (V) supplied to ABS actuator and electric unit
(control unit) is displayed.
GEAR
(1 , 2

, 3, 4, 5) ×× × Gear position (1, 2, 3, 4, 5) judged by transmission
range switch signal is displayed.
SLCT LVR POSI
(P, N, D) ×× × Shift position (P, N, D) judged by transmission range
switch signal.
ENGINE SPEED
(rpm) ×× ×
Engine speed (rpm) judged by CAN communication
signal is displayed.
YAW R AT E S E N
(d/s) ×× × Yaw rate (d/s) detected by yaw rate sensor is dis-
played.
R POSI SIG
(On/Off) ––
×Reverse shift position (On/Off) judged by PNP switch
signal.
4WD FAIL REQ
(On/Off) ––
×Transfer control unit fail-safe mode (On/Off) is dis-
played.
N POSI SIG
(On/Off) ––
×Shift position judged by transmission range switch
signal.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
Revision: April 20092010 QX56

DIAGNOSIS SYSTEM [ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
BRC-25
< FUNCTION DIAGNOSIS > [VDC/TCS/ABS]
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P POSI SIG
(On/Off) ––
×Shift position judged by transmission range switch
signal.
CV1
(On/Off) ––
×Front side switch-over solenoid valve (cut valve) (On/
Off) status is displayed.
CV2
(On/Off) ––
×Rear side switch-over solenoid valve (cut-valve) (On/
Off) status is displayed.
SV1
(On/Off) ––
×Front side switch-over solenoid valve (suction valve)
(On/Off) status is displayed.
SV2
(On/Off) ––
×Rear side switch-over solenoid valve (suction valve)
(On/Off) status is displayed.
2WD/4WD
(2WD/4WD) ––
×It recognizes on software whether it is 2WD and
whether it is in 4WD state.
ACCEL POS SIG
(%) ×
– ×Throttle valve open/close status judged by CAN com-
munication signal is displayed.
SIDE G-SENSOR
(m/s
2) ×
– ×Transverse acceleration detected by side G-sensor is
displayed.
STR ANGLE SIG
(deg) ×
– ×Steering angle detected by steering angle sensor is
displayed.
BST OPER SIG
(On/Off) ––
×Active booster operation (On/Off) status is displayed.
PRESS SENSOR
(bar) ×
– ×Brake pressure detected by pressure sensor is dis-
played.
EBD SIGNAL
(On/Off) ––
×EBD operation (On/Off) status is displayed.
ABS SIGNAL
(On/Off) ––
×ABS operation (On/Off) status is displayed.
TCS SIGNAL
(On/Off) ––
×TCS operation (On/Off) status is displayed.
VDC SIGNAL
(On/Off) ––
×VDC operation (On/Off) status is displayed.
EBD FAIL SIG
(On/Off) ––
×EBD fail signal (On/Off) status is displayed.
ABS FAIL SIG
(On/Off) ––
×ABS fail signal (On/Off) status is displayed.
TCS FAIL SIG
(On/Off) ––
×TCS fail signal (On/Off) status is displayed.
VDC FAIL SIG
(On/Off) ––
×VDC fail signal (On/Off) status is displayed.
CRANKING SIG
(On/Off) ––
×The input state of the key SW START position signal
is displayed.
FLUID LEV SW
(On/Off) ×
– ×Brake fluid level switch (On/Off) status is displayed.
PRESS SEN2
(bar) ––
×Brake pressure detected by pressure sensor is dis-
played.
DELTA S SEN
(mm) ––
×The amount of stroke sensor movements in the active
booster detected by DELTA S SEN is displayed.
RELEASE SW NO
(On/Off) ––
×Release switch signal (On/Off) status is displayed.
“On” indicates that the brake pedal is depressed. “Off”
indicates that the brake pedal is released.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAI
N
SIGNALS SELECT
ION
FROM MENU
Revision: April 20092010 QX56

BRC-26
< FUNCTION DIAGNOSIS >[VDC/TCS/ABS]
DIAGNOSIS SYSTEM [
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL
UNIT)]
×: Applicable
–: Not applicable
ACTIVE TEST MODE
CAUTION:
• Do not perform active test while driving vehicle.
• Make sure to completely bleed air from brake system.
• The active test cannot be performed with the ABS warning lamp, VDC OFF indicator lamp, SLIP indi-
cator lamp or brake warning lamp on.
• ABS warning lamp, VDC OFF indicator lamp, SLIP indicator lamp and brake warning lamp are on
during active test.
NOTE:
• When active test is performed while depressing the pedal, the pedal depression amount will change. This is
normal. (Only solenoid valve and ABS motor.)
• “TEST IS STOPPED” is displayed 10 seconds after operation start.
• After “TEST IS STOPPED” is display ed, to perform test again, touch BACK.
Test Item
SOLENOID VALVE• When performing an active test of the ABS function, select the “MAIN SIGNAL S” for each test item.
• For ABS solenoid valve, touch “Up”, “Keep”, and “D own” on the display screen. For ABS solenoid valve
(ACT), touch “Up”, “ACT UP”, “ACT KEEP” and confirm that solenoid valves operate as shown in the table
below.
RELEASE SW NC
(On/Off) ––
×Release switch signal (On/Off) status is displayed.
“Off” indicates that the brake pedal is depressed. “On”
indicates that the brake pedal is released.
OHB FAIL
(On/Off) ––
×OHB fail status is displayed.
HBA FAIL
(On/Off) ––
×HBA fail status is displayed.
OHB SIG
(On/Off) ––
×OHB operation (On/Off) status is displayed.
HBA SIG
(On/Off) ––
×HBA operation (On/Off) status is displayed.
STP OFF RLY
(On/Off) ––
×Stop lamp relay signal (On/Off) status is displayed.
Item
(Unit) Data monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELECTION
FROM MENU
Operation ABS solenoid valve ABS solenoid valve (ACT)
Up Keep Down Up ACT UP ACT KEEP
FR RH SOL FR RH IN SOL Off On On — —
—
FR RH OUT SOL Off Off On* — — —
FR LH SOL FR LH IN SOL Off On On — —
—
FR LH OUT SOL Off Off On* — — —
RR RH SOL RR RH IN SOL Off On On — —
—
RR RH OUT SOL Off Off On* — — —
RR LH SOL RR LH IN SOL Off On On — —
—
RR LH OUT SOL Off Off On* — — —
FR RH ABS SOLENOID (ACT) FR RH IN SOL — — — Off Off Off
FR RH OUT SOL — — — Off Off Off
CV1 ———OffOnOn
SV1
— — — Off On* Off
Revision: April 20092010 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-87
< ECU DIAGNOSIS > [VDC/TCS/ABS]
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ECU DIAGNOSIS
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Reference ValueINFOID:0000000005148081
VALUES ON THE DIAGNOSIS TOOL
CAUTION:
The display shows the control unit calculation data, so a normal value might be displayed even in the
event the output circuit (harness) is open or short-circuited.
CONSULT-III MONITOR ITEM
Monitor item Display content Data monitor
Condition Reference value in
normal operation
FR LH SENSOR Wheel speed 0 [km/h (MPH)]
Vehicle stopped
Nearly matches the speed meter display
(± 10% or less) Vehicle running
(Note 1)
FR RH SENSOR Wheel speed 0 [km/h (MPH)]
Vehicle stopped
Nearly matches the speed meter display
(± 10% or less) Vehicle running
(Note 1)
RR LH SENSOR Wheel speed 0 [km/h (MPH)]
Vehicle stopped
Nearly matches the speed meter display
(± 10% or less) Vehicle running
(Note 1)
RR RH SENSOR Wheel speed 0 [km/h (MPH)]
Vehicle stopped
Nearly matches the speed meter display
(± 10% or less) Vehicle running
(Note 1)
DECEL G-SEN Longitudinal acceleration detected by Decel
G-Sensor Vehicle stopped
Approx. 0 G
Vehicle running -1.7 to 1.7 G
FR RH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive
(in fail-safe mode) ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
FR RH OUT SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive
(in fail-safe mode) ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
FR LH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive
(in fail-safe mode) ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
FR LH OUT SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive
(in fail-safe mode) ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
Revision: April 20092010 QX56

BRC-88
< ECU DIAGNOSIS >[VDC/TCS/ABS]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
RR RH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
RR RH OUT SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
RR LH IN SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
RR LH OUT SOL Operation status of each solenoid valve Actuator (solenoid valve) is active (“AC-
TIVE TEST” with CONSULT-III) or actua-
tor relay is inactive (in fail-safe mode)
ON
When the actuator (solenoid valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
EBD WARN LAMP EBD warning lamp
(Note 2) When EBD warning lamp is ON
ON
When EBD warning lamp is OFF OFF
STOP LAMP SW Stop lamp switch signal status When brake pedal is depressed
ON
When brake pedal is released OFF
MOTOR RELAY Motor and motor relay operation When the motor relay and motor are op-
erating
ON
When the motor relay and motor are not
operating OFF
ACTUATOR RLY Actuator relay operation When the actuator relay is operating
ON
When the actuator relay is not operating OFF
ABS WARN LAMP ABS warning lamp
(Note 2) When ABS warning lamp is ON
ON
When ABS warning lamp is OFF OFF
OFF LAMP VDC OFF indicator lamp
(Note 2) When VDC OFF indicator lamp is ON
ON
When VDC OFF indicator lamp is OFF OFF
OFF SW VDC OFF switch ON/OFF VDC OFF switch ON
(When VDC OFF indicator lamp is ON)
ON
VDC OFF switch OFF
(When VDC OFF indicator lamp is OFF) OFF
SLIP LAMP SLIP indicator lamp
(Note 2) When SLIP indicator lamp is ON
ON
When SLIP indicator lamp is OFF OFF
BATTERY VOLT Battery voltage supplied to the ABS actuator
and electric unit (control unit) Ignition switch ON
10 – 16 V
GEAR Gear position determined by TCM 1st gear
2nd gear
3rd gear
4th gear
5th gear 1
2
3
4
5
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
Revision: April 20092010 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-89
< ECU DIAGNOSIS > [VDC/TCS/ABS]
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SLCT LVR POSI A/T selector lever position P position
R position
N position
D positionP
R
N
D
ENGINE SPEED With engine running With engine stopped
0 rpm
Engine running Almost in accor-
dance with tachome-
ter display
YAW RATE SEN Yaw rate detected by yaw rate/side/decel G
sensor When vehicle is stopped
Approx. 0 d/s
When vehicle turning −75 to 75 d/s
R POSI SIG Transmission range switch signal ON/OFF
condition A/T shift position = R position
ON
A/T shift position = other than R position OFF
4WD FAIL REQ
(Note 3) Transfer control unit fail-safe signal When transfer control unit is in fail-safe
mode
ON
When transfer control unit is normal OFF
N POSI SIG Transmission range switch signal ON/OFF
condition A/T shift position = N position
ON
A/T shift position = other than N position OFF
P POSI SIG Transmission range switch signal ON/OFF
condition A/T shift position = P position
ON
A/T shift position = other than P position OFF
CV1 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
CV2 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
SV1 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
SV2 VDC switch-over valve When actuator (switch-over valve) is ac-
tive (“ACTIVE TEST” with CONSULT-III)
or actuator relay is inactive (when in fail-
safe mode)
ON
When actuator (switch-over valve) is not
active and actuator relay is active (igni-
tion switch ON) OFF
2WD/4WD Drive axle 2WD model
2WD
4WD model 4WD
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
Revision: April 20092010 QX56

BRC-90
< ECU DIAGNOSIS >[VDC/TCS/ABS]
ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
ACCEL POS SIG Throttle actuator opening/closing is dis-
played (linked with accelerator pedal) Accelerator pedal not depressed (ignition
switch is ON)
0 %
Accelerator pedal depressed (ignition
switch is ON) 0 - 100 %
SIDE G-SENSOR Transverse G detected by side G sensor Vehicle stopped
Approx. 0 m/s
2
Vehicle turning rightNegative value
(m/s2)
Vehicle turning left Positive value
(m/s
2)
STR ANGLE SIG Steering angle detected by steering angle
sensor Straight-ahead
Approx. 0°
Steering wheel turned –720 to 720°
BST OPER SIG Active booster operation Active booster is active
ON
Active booster is inactive OFF
PRESS SENSOR Brake fluid pressure detected by front pres-
sure sensor With ignition switch turned ON and brake
pedal released
Approx. 0 bar
With ignition switch turned ON and brake
pedal depressed –40 to 300 bar
EBD SIGNAL EBD operation EBD is active
ON
EBD is inactive OFF
ABS SIGNAL ABS operation ABS is active
ON
ABS is inactive OFF
TCS SIGNAL TCS operation TCS is active
ON
TCS is inactive OFF
VDC SIGNAL VDC operation VDC is active
ON
VDC is inactive OFF
EBD FAIL SIG EBD fail-safe signal In EBD fail-safe
ON
EBD is normal OFF
ABS FAIL SIG ABS fail-safe signal In ABS fail-safe
ON
ABS is normal OFF
TCS FAIL SIG TCS fail-safe signal In TCS fail-safe
ON
TCS is normal OFF
VDC FAIL SIG VDC fail-safe signal In VDC fail-safe
ON
VDC is normal OFF
CRANKING SIG Crank operation Crank is active
ON
Crank is inactive OFF
FLUID LEV SW Brake fluid level switch signal status When brake fluid level switch ON
ON
When brake fluid level switch OFF OFF
PRESS SEN2 Brake fluid pressure detected by rear pres-
sure sensor With ignition switch turned ON and brake
pedal released
Approx. 0 bar
With ignition switch turned ON and brake
pedal depressed –40 to 300 bar
DELTA S SEN Value detected by delta stroke sensor When brake pedal is depressed
1.05 - 1.80 mm
When brake pedal is released 0.00 mm (+0.6/-0.4)
RELEASE SW NO Active booster signal status When brake pedal is depressed
ON
When brake pedal is released OFF
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
Revision: April 20092010 QX56

ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)BRC-91
< ECU DIAGNOSIS > [VDC/TCS/ABS]
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NOTE:
• 1: Confirm tire pr essure is normal.
• 2: On and off timing for warning lamp and indicator lamp.
• 3: Only 4WD models.
- ABS warning lamp: Refer to BRC-82, "
Description".
- Brake warning lamp: Refer to BRC-83, "
Description".
- VDC OFF indicator lamp: Refer to BRC-84, "
Description".
- SLIP indicator lamp: Refer to BRC-86, "
Description".
TERMINAL LAYOUT
RELEASE SW NC Active booster signal status When brake pedal is depressed OFF
When brake pedal is released
ON
OHB FAIL OHB fail safe signal OHB is active
ON
OHB is inactive OFF
HBA FAIL HBA fail safe signal HBA is active
ON
HBA is inactive OFF
OHB SIG OHB operation In OHB fail-safe
ON
OHB is normal OFF
HBA SIG HBA operation In HBA fail-safe
ON
HBA is normal OFF
STP OFF RLY Stop lamp relay signal When stop lamp relay is ON
ON
When stop lamp relay is OFF OFF
Monitor item
Display content Data monitor
Condition Reference value in
normal operation
AWFIA0032ZZ
Revision: April 20092010 QX56