2004 INFINITI QX56 stop start

BRC-4
[VDC/TCS/ABS]
PRECAUTIONS
Revision: August 20072004 QX56

If YES, GO TO 2.

If NO, GO TO 5.
2. Is there any indication other than indications relating to CAN communication system in the self-diagnosis
results?

If YES, GO TO 3.

If NO, GO TO 4.
3. Based on self-diagnosis results unrelated to CAN communication, carry out the inspection.
4. Malfunctions may be detected in self-diagnosis depending on control units carrying out CAN communica-
tion. Therefor, erase the self-diagnosis results.
5. Diagnose CAN communication system. Refer to BRC-10, "
CAN COMMUNICATION" .
Precautions for Brake ControlEFS003QD

During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.

Just after starting vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.

Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel,
or snow-covered (fresh, deep snow) roads.

When an error is indicated by ABS or another warning lamp, collect all necessary information from cus-
tomer (what symptoms are present under what conditions) and check for simple causes before starting
diagnosis. Besides electrical system inspection, check booster operation, brake fluid level, and fluid leaks.

If incorrect tire sizes or types are installed on the vehicle or brake pads are not Genuine NISSAN parts,
stopping distance or steering stability may deteriorate.

If there is a radio, antenna or related wiring near control module, ABS function may have a malfunction or
error.

If aftermarket parts (car stereo, CD player, etc.) have been installed, check for incidents such as harness
pinches, open circuits or improper wiring.

If the following components are replaced with non-genuine components or modified, the VDC OFF indica-
tor lamp and SLIP indicator lamp may turn on or the VDC system may not operate properly. Components
related to suspension (shock absorbers, struts, springs, bushings, etc.), tires, wheels (exclude specified
size), components related to brake system (pads, rotors, calipers, etc.), components related to engine
(muffler, ECM, etc.), components related to body reinforcement (roll bar, tower bar, etc.).

Driving with broken or excessively worn suspension components, tires or brake system components may
cause the VDC OFF indicator lamp and the SLIP indicator lamp to turn on, and the VDC system may not
operate properly.

When the TCS or VDC is activated by sudden acceleration or sudden turn, some noise may occur. The
noise is a result of the normal operation of the TCS and VDC.

When driving on roads which have extreme slopes (such as mountainous roads) or high banks (such as
sharp curves on a freeway), the VDC may not operate normally, or the VDC warning lamp and the SLIP
indicator lamp may turn on. This is not a problem if normal operation can be resumed after restarting the
engine.

Sudden turns (such as spin turns, acceleration turns), drifting, etc. with VDC turned off may cause the yaw
rate/side G sensor to indicate a problem. This is not a problem if normal operation can be resumed after
restarting the engine.
Precautions for CAN SystemEFS003QE

Do not apply voltage of 7.0V or higher to terminal to be measured.

Maximum open terminal voltage of tester in use must be less than 7.0V.

Before checking harnesses, turn ignition switch OFF and disconnect battery negative cable.

BRC-8
[VDC/TCS/ABS]
SYSTEM DESCRIPTION
Revision: August 20072004 QX56
ABS FunctionEFS003QJ

The Anti-Lock Brake System detects wheel revolution while braking and improves handling stability during
sudden braking by electrically preventing wheel lockup. Maneuverability is also improved for avoiding
obstacles.

If the electrical system malfunctions, the Fail-Safe function is activated, the ABS becomes inoperative and
the ABS warning lamp turns on.

The electrical system can be diagnosed using CONSULT-II.

During ABS operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.

Just after starting the vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.

Stopping distance may be longer than that of vehicles without ABS when vehicle drives on rough, gravel,
or snow-covered (fresh, deep snow) roads.
EBD FunctionEFS003QK

Electronic Brake Distribution is a function that detects subtle slippages between the front and rear wheels
during braking, and it improves handling stability by electronically controlling the brake fluid pressure
which results in reduced rear wheel slippage.

If the electrical system malfunctions, the Fail-Safe function is activated, the EBD and ABS become inoper-
ative, and the ABS warning lamp and BRAKE warning lamp are turned on.

The electrical system can be diagnosed using CONSULT-II.

During EBD operation, the brake pedal may vibrate lightly and a mechanical noise may be heard. This is
normal.

Just after starting the vehicle, the brake pedal may vibrate or a motor operating noise may be heard from
engine compartment. This is a normal status of operation check.
TCS FunctionEFS003QL

Spinning of the drive wheels is detected by the ABS actuator and electric unit (control unit) using inputs
from the wheel speed sensors. If wheel spin occurs, the drive wheel right and left brake fluid pressure
control and engine fuel cut are activated while the throttle value is restricted to reduce the engine torque
and decrease the amount of wheel spin. In addition, the throttle opening is controlled to achieve the opti-
mum engine torque.

Depending on road condition, the vehicle may have a sluggish feel. This is normal, because optimum trac-
tion has the highest priority during TCS operation.

TCS may be activated during sudden vehicle acceleration, wide open throttle acceleration, sudden trans-
mission shifts or when the vehicle is driven on a road with a varying surface friction coefficient.

The SLIP indicator lamp flashes to inform the driver of TCS operation.
VDC FunctionEFS003QM

In addition to the ABS/TCS function, the driver steering amount and brake operation amount are detected
from the steering angle sensor and front and rear pressure sensors, and the vehicle's driving status
(amount of under steering/over steering) is determined using inputs from the yaw rate sensor/side G sen-
sor, wheel speed sensors, etc. and this information is used to improve vehicle stability by controlling the
braking and engine torque application to the wheels.

The SLIP indicator lamp flashes to inform the driver of VDC operation.

During VDC operation, the vehicle body and brake pedal may vibrate lightly and a mechanical noise may
be heard. This is normal.

The ABS warning lamp, VDC OFF indicator lamp and SLIP indicator lamp may turn on when the vehicle is
subject to strong shaking or large vibration, such as when the vehicle is on a turn table or a ship while the
engine is running or on a steep slope. In this case, restart the engine on a normal road and if the ABS
warning lamp, VDC OFF indicator lamp and SLIP indicator lamp turn off, there is no problem.
Fail-Safe FunctionEFS003QN
CAUTION:
If the Fail-Safe function is activated, perform the Self Diagnosis for ABS/TCS/VDC system.

BRC-24
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Warning Lamp and Indicator TimingEFS003QV
X: ON
—: OFF
Control Unit Input/Output Signal StandardEFS003QW
REFERENCE VALUE FROM CONSULT-II
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.
ConditionABS
warning lampVDC OFF
indicator lampSLIP
indicator lampRemarks
When the ignition switch is OFF — — — —
After the ignition switch is turned
ON for approx. 1 second×××—
After the ignition switch is turned
ON for approx. 2 seconds———Lamp goes off approx. 2 seconds
after the engine is started.
When the VDC OFF switch is
pressed (VDC function OFF)—×——
ABS/TCS/VDC malfunction×××—
××—When the ABS actuator and elec-
tric unit (control unit) is malfunc-
tioning (power supply or ground
malfunction).
When the VDC is malfunctioning —××—
Monitor item Display contentData monitor
Note: Error inspection
checklist
ConditionReference value in
normal operation
N POSI SIGPNP switch signal ON/
OFF conditionA/T shift position = N position ON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"A/T shift position = other than
N positionsOFF
P POSI SIGPNP switch signal ON/
OFF conditionA/T shift position P position ON
BRC-54, "
CAN Commu-
nication System Inspec-
tion"A/T shift position = other than
P positionsOFF
GEAR A/T gear position1st gear 1
— 2nd gear 2
3rd gear 3
4th gear 4
5th gear 5
FR RH SENSOR
FR LH SENSOR
RR RH SENSOR
RR LH SENSORWheel speedVehicle stopped 0 [km/h (MPH)]
BRC-38, "
Wheel Sensor
System Inspection"Vehicle running (Note 1)Almost in accor-
dance with speed-
ometer display
(within ±10%)
ACCEL POS SIG Open/close condition
of throttle valve (linked
with accelerator pedal).Accelerator pedal not
depressed (ignition switch is
ON)0%
BRC-54, "
CAN Commu-
nication System Inspec-
tion"Depress accelerator pedal
(ignition switch is ON)0 to 100%
ENGINE SPEED With engine runningWith engine stopped 0 rpm
BRC-39, "
Engine System
Inspection"Engine runningAlmost in accor-
dance with
tachometer display

TROUBLE DIAGNOSIS
BRC-29
[VDC/TCS/ABS]
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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

TROUBLE DIAGNOSIS
BRC-33
[VDC/TCS/ABS]
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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
BRC-35
[VDC/TCS/ABS]
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×: Applicable
–: Not applicableVDC SIGNAL
(ON/OFF)––×VDC operation (ON/OFF) status is
displayed.
EBD WARN LAMP – –×Brake warning lamp (ON/OFF) sta-
tus is displayed.
SLCT LVR POSI×××Shift position judged by PNP switch
signal.
R POSI SIG – –×Shift position judged by PNP switch
signal.
4WD FAIL REQ – –×The state of 4WD controller is dis-
played by CAN communication sig-
nal.
2WD/4WD – –×It recognizes on software whether it
is 2WD and whether it is in 4WD
state.
BST OPER SIG – –×Active booster operation (ON/OFF)
status is displayed.
PRESS SENSOR×–×Brake pressure detected by pres-
sure sensor is displayed.
CRANKING SIG – –×The input state of the key SW
START position signal is displayed.
PRESS SEN 2 – –×Brake pressure detected by pres-
sure sensor is displayed.
DELTA S SEN – –×The amount of stroke sensor move-
ments in the active booster
detected by DELTA S SEN is dis-
played.
RELEASE SW NO – –×Release switch signal (ON/OFF)
status is displayed. "ON" indicates
that the brake pedal is depressed.
"OFF" is that the brake pedal is
released.
RELEASE SW NC – –×Release switch signal (ON/OFF)
status is displayed. "OFF" indi-
cates that the brake pedal is
depressed on. "ON" is that the
brake pedal is released.
OHB FAIL – –×OHB fail status is displayed.
HBA FAIL – –×HBA fail status is displayed.
OHB SIG – –×OHB operation (ON/OFF) status is
displayed.
HBA SIG – –×HBA operation (ON/OFF) status is
displayed.
PRES CTRL ACC – –×Pressure control state (ON/OFF) is
displayed. It is applied only to an
ICC vehicle.
PRES FAIL ACC – –×Pressure control fail state (ON/
OFF) is displayed. It is applied only
to an ICC vehicle.
STP OFF RLY – –×Stop lamp relay signal (ON/OFF)
status is displayed. Item
(Unit)Data monitor item selection
Remarks
ECU INPUT
SIGNALSMAIN
SIGNALSSELECTION
FROM MENU

BRC-36
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
ACTIVE TEST
CAUTION:

Do not perform active test while driving.

Make sure to completely bleed air from the brake system.

The ABS and brake (EBD) warning lamps turn on during the active test.
Operation Procedure
1. Connect the CONSULT-II and CONSULT-II CONVERTER to the data link connector and start the 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.
2. Touch “START (NISSAN BASED VHCL) ” on the display screen.
3. Touch “ABS”.
If “ABS” is not indicated, go to GI-39, "
CONSULT-II Data Link Connector (DLC) Circuit" .
4. Touch “ACTIVE TEST”.
5. The test item selection screen is displayed.
6. Touch necessary test item.
7. With the “MAIN SIGNALS” display selected, touch “START”.
8. The Active Test screen will be displayed, so conduct the following test.
Solenoid Valve Operation Chart
*: ON for 1 to 2 seconds after the touch, and then OFF
NOTE:

If active test is performed with brake pedal depressed, pedal stroke may change. This is normal.

“TEST IS STOPPED” is displayed approximately 10 seconds after operation starts.

After “TEST IS STOPPED” is displayed, to perform test again, repeat Step 6.
LBR379
OperationABS solenoid valve ABS solenoid valve (ACT)
UP KEEP DOWN UPACTUA-
TO R U PACTUA-
TOR KEEP
FR RH SOL
FR RH ABS SOLE-
NOID (ACT)FR RH IN SOL OFF ON ON OFF OFF OFF
FR RH OUT SOL OFF OFF ON* OFF OFF OFF
FR LH SOL
FR LH ABS SOLE-
NOID (ACT)FR LH IN SOL OFF ON ON OFF OFF OFF
FR LH OUT SOL OFF OFF ON* OFF OFF OFF
RR RH SOL
RR RH ABS SOLE-
NOID (ACT)RR RH IN SOL OFF ON ON OFF OFF OFF
RR RH OUT SOL OFF OFF ON* OFF OFF OFF
RR LH SOL
RR LH ABS SOLE-
NOID (ACT)RR LH IN SOL OFF ON ON OFF OFF OFF
RR LH OUT SOL OFF OFF ON* OFF OFF OFF
REAR SOLRR RH IN SOL OFF ON ON OFF OFF OFF
RR RH OUT SOL OFF OFF ON* OFF OFF OFF
RR LH IN SOL OFF ON ON OFF OFF OFF
RR LH OUT SOL OFF OFF ON* OFF OFF OFF

TROUBLE DIAGNOSIS
BRC-37
[VDC/TCS/ABS]
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ABS Motor
Touch “ON” and “OFF” on the screen. Check that ABS motor relay
operates as shown in table below.
NOTE:

If active test is performed with brake pedal depressed, pedal
stroke may change. This is normal.

“TEST IS STOPPED” is displayed approximately 10 seconds
after operation starts.
Operation ON OFF
ABS actuator relay ON ON
ABS motor relay ON OFF
SFIA0593E