2004 INFINITI QX56 Can communication

TROUBLE DIAGNOSIS
BRC-23
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
Basic InspectionEFS003QU
BRAKE FLUID LEVEL, FLUID LEAK, AND BRAKE PAD INSPECTION
1. Check fluid level in the brake fluid reservoir. If fluid level is low, add fluid.
2. Check the brake piping and around the ABS actuator and electric unit (control unit) for leaks. If there is
leaking or seeping fluid, check the following items.

If ABS actuator and electric unit (control unit) connection is loose, tighten the piping to the specified
torque and recheck for leaks.

If there is damage to the connection flare nut or ABS actuator and electric unit (control unit) threads,
replace the damaged part and recheck for leaks.

When there is fluid leaking or seeping from a fluid connection, use a clean cloth to wipe off the fluid and
recheck for leaks. If fluid is still seeping out, replace the damaged part. If the fluid is leaking at the ABS
actuator and electric unit (control unit), replace the ABS actuator and electric unit (control unit) assem-
bly.
CAUTION:
The ABS actuator and electric unit (control unit) cannot be disassembled and must be replaced
as an assembly.
3. Check the brake pads for excessive wear.
POWER SYSTEM TERMINAL LOOSENESS AND BATTERY INSPECTION
Make sure the battery positive cable, negative cable and ground connection are not loose. In addition, make
sure the battery is sufficiently charged.
ABS WARNING LAMP, SLIP INDICATOR LAMP AND VDC OFF INDICATOR LAMP INSPECTION
1. Make sure ABS warning lamp, SLIP indicator lamp and VDC OFF indicator lamp (when VDC OFF switch
is off), turn on for approximately 2 seconds when the ignition switch is turned ON. If they do not, check the
VDC OFF indicator lamp and the VDC OFF switch. Refer to BRC-56, "
VDC OFF SWITCH" . Check CAN
communications. If there are no errors with the VDC OFF switch or CAN communication system, check
combination meter. Refer to DI-5, "
COMBINATION METERS" .
2. Make sure the lamps turn off approximately 2 seconds after the ignition switch is turned ON. If the lamp
does not turn off, conduct self-diagnosis.
3. With the engine running, make sure the VDC OFF indicator lamp turns on and off when the VDC OFF
switch is turned on and off. If the indicator lamp status does not correspond to switch operation, check the
VDC OFF switch. Refer to BRC-56, "
VDC OFF SWITCH" .
4. Make sure ABS warning lamp, SLIP indicator lamp and VDC OFF indicator lamp turn off approximately 2
seconds after the engine is started. If ABS warning lamp, SLIP indicator lamp or VDC OFF indicator lamp
have not turned off 10 seconds after the engine has been started, conduct self-diagnosis of the ABS actu-
ator and electric unit (control unit).
5. After conducting the self-diagnosis, be sure to erase the error memory. Refer to BRC-28, "
CONSULT-II
Function (ABS)" .

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]
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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-31
[VDC/TCS/ABS]
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Revision: August 20072004 QX56
FR LH IN ABS SOL
[C1120]Circuit of front LH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
BRC-43, "
Solenoid and
VDC Change-Over Valve
System Inspection"
FR LH OUT ABS SOL
[C1121]Circuit of front LH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
RR RH IN ABS SOL
[C1126]Circuit of rear RH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
RR RH OUT ABS SOL
[C1127]Circuit of rear RH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
FR RH IN ABS SOL
[C1122]Circuit of front RH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
FR RH OUT ABS SOL
[C1123]Circuit of front RH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
RR LH IN ABS SOL
[C1124]Circuit of rear LH IN ABS solenoid is open or shorted, or control
line is open or shorted to power supply or ground.
RR LH OUT ABS SOL
[C1125] Circuit of rear LH OUT ABS solenoid is open or shorted, or con-
trol line is open or shorted to power supply or ground.
CV1
[C1164]Front side VDC switch-over solenoid valve (cut valve) is open or
shorted, or control line is open or shorted to power supply or
ground.
CV2
[C1165]Rear side VDC switch-over solenoid valve (cut valve) is open or
shorted, or control line is open or shorted to power supply or
ground.
SV1
[C1166]Front side VDC switch-over solenoid valve (suction valve) is
open or shorted, or control line is open or shorted to power sup-
ply or ground.
SV2
[C1167]Rear side VDC switch-over solenoid valve (suction valve) is open
or shorted, or control line is open or shorted to power supply or
ground.
PUMP MOTOR (Note 3)
[ C 1111 ]During actuator motor operation with ON, when actuator motor
turns OFF or when control line for actuator motor relay is open.BRC-44, "
Actuator
Motor, Motor Relay, and
Circuit Inspection"During actuator motor operation with OFF, when actuator motor
turns ON or when control line for relay is shorted to ground.
BATTERY VOLTAGE
[ABNORMAL]
[C1109]ABS actuator and electric unit (control unit) power voltage is too
low.BRC-46, "
ABS/TCS/
VDC Control Unit Power
and Ground Systems
Inspection"
ST ANGLE SEN SIGNAL
[C1144]Neutral position correction of steering angle sensor is not fin-
ished.BRC-55, "
Inspection For
Self-diagnosis Result
"ST ANGLE SEN SIG-
NAL""
ST ANG SEN COM CIR
[C1156]CAN communication line or steering angle sensor has generated
an error.BRC-40, "Steering Angle
Sensor System"
G-SENSOR
[ C 111 3 ]Longitudinal G-sensor is malfunctioning, or signal line of longitu-
dinal G-sensor is open or shorted.BRC-41, "Yaw Rate/
Side/Decel G Sensor
System Inspection"
CONTROLLER FAILURE
[ C 111 0 ]Internal malfunction of ABS actuator and electric unit (control
unit)BRC-40, "ABS/TCS/
VDC Control Unit
Inspection"
CAN COMM CIRCUIT
[U1000]

CAN communication line is open or shorted.

ABS actuator and electric unit (control unit) internal malfunc-
tion

Battery voltage for ECM is suddenly interrupted for approxi-
mately 0.5 second or more.BRC-54, "
CAN Commu-
nication System Inspec-
tion" (Note 2) Self-diagnostic item Malfunction detecting condition Check system

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]
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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