2007 INFINITI QX56 brake sensor

REAR SUSPENSION MEMBER
RSU-27
< SERVICE INFORMATION >
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Rear Load Leveling Air Suspension System
REMOVAL
1. Use the CONSULT-II “EXHAUST SOLENOID” active test to release the air pressure from the rear load
leveling air suspension system.
2. Disconnect the electrical connectors for the height sensor and the rear load leveling air suspension com-
pressor assembly.
3. Unclip the rubber cover to access the rear load leveling air suspension compressor assembly.
4. Disconnect the rear load leveling air suspension hoses at the
rear load leveling air suspension compressor assembly.
• To disconnect the hoses, push in on the lock ring using a suit-
able tool and pull the hose out.
5. Remove both of the rear wheel and tire assemblies using power
tool.
6. Remove the brake caliper without disconnecting the brake
hoses, using power tool. Reposition the brake caliper out of the
way using a suitable wire. Refer to BR-25, "
Removal and Instal-
lation of Brake Caliper and Disc Rotor" .
CAUTION:
10. Shock absorber 11. Suspension arm 12. Lower rubber seat
13. Coil spring 14. Upper rubber seat 15. Rear suspension member
16. Spare tire bracket 17. Bound bumper
AWEIA0076ZZ
1. Rear load leveling air suspension
hose, RH2. Shock absorber, RH 3. Height sensor
4. Rear load leveling air suspension
hose, LH5. Shock absorber, LH 6. Rear load leveling air suspension
compressor assembly (includes the
bracket and rubber cover)
⇐Front
LEIA0074E

RSU-28
< SERVICE INFORMATION >
REAR SUSPENSION MEMBER
• Do not crimp or stretch the brake hose when repositioning the brake caliper out of the way.
• Do not press brake pedal while the brake caliper is removed.
7. Remove the spare tire.
8. Disconnect the two rear ABS sensor electrical connectors.
9. Remove the two rear drive shafts. Refer to RAX-7, "
Removal and Installation" .
10. Remove the rear final drive. Refer to RFD-14
.
11. Remove the EVAP canister bolt from the top of the rear suspension member.
12. Disconnect the parking brake cables from the brackets on the rear suspension member.
13. Set a suitable jack to support each of the rear lower links and the
coil spring tension.
14. Remove both of the rear lower link outer bolts and lower the jack to remove the rear coil springs.
15. Remove the two bolts to disconnect the seat belt latch anchor
from the rear suspension member.
16. Disconnect both of the connecting rods from the rear stabilizer
bar.
17. Set a suitable jack under the rear suspension member.
18. Remove the six rear suspension member bolts.
19. Slowly lower the jack to remove the rear suspension member,
suspension arm, front and rear lower links and stabilizer bar as
an assembly.
20. If necessary, remove the suspension arm, spare tire bracket,
height sensor, rear load leveling air suspension hoses, stabilizer
bar, knuckle, and front and rear lower links from the rear suspension member.
INSPECTION AFTER REMOVAL
Check the rear suspension member for deformation, cracks, and other damage and replace if necessary.
INSTALLATION
Installation is in the reverse order of removal.
• When raising the rear suspension member assembly, use the
locating pins to align the rear suspension member to the vehicle
body.
LEIA0077E
LEIA0075E
LEIA0083E

TF-18
< SERVICE INFORMATION >
ALL-MODE 4WD SYSTEM
LINE PRESSURE SWITCH
• With the transfer system design, control of the oil pressure provides the transmission of drive torque to the
front wheels. The main pressure to control the oil pressure is referred to as the line pressure.
• The line pressure switch determines whether or not adequate line pressure has built up under different oper-
ating conditions.
• The line pressure switch turns ON when line pressure is produced.
• The line pressure switch senses line pressure abnormalities and turns the 4WD warning lamp ON.
CLUTCH PRESSURE SWITCH
• The clutch pressure switch determines whether or not adequate clutch pressure has built up under different
operating conditions.
• The clutch pressure switch turns ON when clutch pressure is produced.
• The clutch pressure switch senses clutch pressure abnormalities and turns the 4WD warning lamp ON.
TRANSFER FLUID TEMPERATURE SENSOR
The transfer temperature sensor detects the transfer fluid temperature and sends a signal to the transfer con-
trol unit.
TRANSFER CONTROL UNIT
• Transfer control unit controls transfer control device by input signals of each sensor and each switch.
• Self-diagnosis can be done.
TRANSFER CONTROL DEVICE
The transfer control device changes the state of transfer assembly between 2WD, AUTO, 4H⇔4LO with the
2WD, AUTO, 4H and 4LO signals of 4WD shift switch.
NOTE:
• To shift between 4H⇔4LO, stop the vehicle, depress the brake pedal and shift the transmission selector to
the "N" position. Depress and turn the 4WD shift switch. The shift switch will not shift to the desired mode if
the transmission is not in "N" or the vehicle is moving. The 4LO indicator lamp will be lit when the 4LO is
engaged.
• Actuator motor and actuator position switch are integrated.
4WD SHIFT SWITCH AND INDICATOR LAMP
4WD Shift Switch
The 4WD shift switch allows selection from 2WD, AUTO, 4H or 4LO.
4WD Shift Indicator Lamp
• Displays driving conditions selected by 4WD shift switch with 2WD, AUTO and 4H indicators while engine is
running. (When 4WD warning lamp is turned on, all 4WD shift indicator lamps are turned off.)
• Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4LO Indicator Lamp
• Displays 4LO condition while engine is running. 4LO indicator lamp flashes if transfer gear does not shift
completely under 2WD, AUTO, 4H⇔4LO. (When 4WD warning lamp is turned on, 4LO indicator lamp is
turned off.)
• Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4WD WARNING LAMP
Turns ON or FLASH when there is a malfunction in 4WD system.
Also turns ON when ignition switch is turned ON, for purpose of lamp check. Turns OFF for approximately 1
second after the engine starts if system is normal.
4WD Warning Lamp Indication
Condition Content 4WD warning lamp
During self-diagnosis Indicates the malfunction position by number of flickers. Flickers at malfunction mode.
Lamp check*Checks the lamp by turning ON during engine starting. After
engine starts, it turns OFF if there are no malfunctions.ON
Malfunction in 4WD system*Turns ON to indicate malfunction. When ignition switch is
turned to “OFF” or the malfunction is corrected, it turns OFF.ON
When vehicle is driven with different
diameters of front and rear tiresFlickers once every 2 seconds.
Turns OFF when ignition switch is “OFF”.Flickers once every 2 sec-
onds.

TROUBLE DIAGNOSIS
TF-35
< SERVICE INFORMATION >
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• Heavy tight-corner braking symptom occurs when vehicle is driven in the following conditions: 4WD shift
switch is "4H" or "4LO", steering wheel is turned fully to either side.
Transfer Control Unit Input/Output Signal Reference ValueINFOID:0000000003532526
TRANSFER CONTROL UNIT INSPECTION TABLE
Specifications with CONSULT-II
Monitored item [Unit] Content Condition Display value
VHCL/S SEN·FR [km/h]
or [mph]Front wheel speedVehicle stopped 0 km/h (0 MPH)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±10%)
VHCL/S SEN·RR [km/h]
or [mph]Rear wheel speedVehicle stopped 0 km/h (0 MPH)
Vehicle running
CAUTION:
Check air pressure of tire under standard condition.Approximately
equal to the indica-
tion on speedome-
ter (Inside of
±10%)
ENGINE SPEED [rpm] Engine speedEngine stopped
(Engine speed: Less than 400 rpm)0 rpm
Engine running
(Engine speed: 400 rpm or more)Approximately
equal to the indica-
tion on tachometer
THRTL POS SEN [V]Accelerator pedal posi-
tion (APP) sensor signal
voltageAccelerator pedal: Release Approx. 0.5V
Accelerator pedal: Fully depressed Approx. 4.0V
FLUID TEMP SE [V]Transfer fluid tempera-
ture signal voltageTransfer fluid temperature approx. 20 - 80°C (68 - 176°F) Approx. 1.1 - 0.3V
BATTERY VOLT [V]Power supply voltage for
transfer control unitIgnition switch: ON Battery voltage
2WD SWITCH [ON/OFF]Input condition from 4WD
shift switch4WD shift switch: 2WD ON
4WD shift switch: AUTO, 4H or 4LO OFF
AUTO SWITCH [ON/
OFF]Input condition from 4WD
shift switch4WD shift switch: AUTO ON
4WD shift switch: 2WD, 4H or 4LO OFF
LOCK SWITCH [ON/
OFF]Input condition from 4WD
shift switch4WD shift switch: 4H ON
4WD shift switch: 2WD, AUTO or 4LO OFF
4L SWITCH [ON/OFF]Input condition from 4WD
shift switch4WD shift switch: 4LO ON
4WD shift switch: 2WD, AUTO or 4H OFF
N POSI SW TF [ON/
OFF]Condition of neutral-4LO
switch• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 2WD,
AUTO or 4HOFF
4WD shift switch: 4H to
4LO (While actuator mo-
tor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON

TROUBLE DIAGNOSIS
TF-39
< SERVICE INFORMATION >
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TRANSFER CONTROL UNIT TERMINAL CONNECTOR LAYOUT
NOTE:
Data are reference value and are measured between each terminal and ground.
SHIFT AC MON2 [ON/
OFF]Check signal for transfer
control unit signal output• Vehicle stopped
• Engine running
• A/T selector lever “N” posi-
tion
• Brake pedal depressed4WD shift switch: 4LO to
4H (“Wait” function is op-
erating.)ON
Except the above OFF
T/F F SPEED [km/h] or
[mph]Displayed, but do not use.
A/T R SPEED [km/h] or
[mph]Condition of vehicle
speed sensor A/T (Revo-
lution sensor)During drivingApproximately
matches the out-
put shaft speed.
AT GEAR POSI [1/2/3/4/
5]Condition of A/T selector
lever positionDisplays actual A/T gear position. 1/2/3/4/5 Monitored item [Unit] Content Condition Display value
WDIA0378E
Te r m i n a lWire
colorItem Condition Data (Approx.)
1 GR 2-4WD shift solenoid valve• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 2WD 0V
4WD shift switch: AUTO, 4H or 4LO Battery voltage
2 B/W4WD shift indicator lamp
(2WD indicator lamp)2WD indicator lamp: OFF Battery voltage
2WD indicator lamp: ON 0V
3 B Ground Always 0V
4 Y/L Transfer shift high relay• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
5 W/B 4WD warning lamp4WD warning lamp: ON 0V
4WD warning lamp: OFF Battery voltage
6 B Ground Always 0V
7 L CAN-H — —
8 P CAN-L — —
9G/W4WD shift switch
(2WD)Ignition switch: ON4WD shift switch: 2WD Battery voltage
4WD shift switch: AUTO, 4H or 4LO 0V

TROUBLE DIAGNOSIS
TF-41
< SERVICE INFORMATION >
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25 V Neutral-4LO switch• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 2WD, AUTO or 4H Battery voltage
4WD shift switch: 4H to 4LO (While actua-
tor motor is operating.)Battery voltage
→ 0V
4WD shift switch: 4LO to 4H (While actua-
tor motor is operating.)0V → Battery
voltage
4WD shift switch: 4LO 0V
27 W/LActuator position switch 2
(High)• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4H, AUTO or 2WD 0V
4WD shift switch: 4LO Battery voltage
28 B/G Sensor ground Always 0V
29 L/W Ignition switch monitorIgnition switch: ON Battery voltage
Ignition switch: OFF 0V
30 SB Shut off relayIgnition switch: ON 0V
Ignition switch: OFF Battery voltage
31 GTransfer fluid temperature
sensorIgnition switch: ONTransfer fluid temperature approx. 20°C
(68°F)1.1V
Transfer fluid temperature approx. 80°C
(176°F)0.3V
33 R/LTransfer shift high relay
monitor• Vehicle stopped
• Engine running
• A/T selector lever
“N” position
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO (“Wait” func-
tion is operating.)Battery voltage
Except the above 0V
34 BR Clutch pressure switch• Vehicle stopped
• Engine running
• A/T selector lever
“D” position4WD shift switch: AUTO or 4H (“Wait” func-
tion is not operating.)0V
• Vehicle stopped
• Engine running4WD shift switch: 2WD (“Wait” function is
not operating.)Battery voltage
35BR/
WLine pressure switch• Ignition switch: ON
• A/T selector lever “D” position
• 4WD shift switch: AUTO0V
• After the vehicle
has been left at
room temperature
for 5 minutes and
more with ignition
switch in “OFF” po-
sition.• Ignition switch: ON
• A/T selector lever: “P” or "N" position
• 4WD shift switch: other than AUTOBattery voltage
40 L ATP switch• Vehicle stopped
• Engine running
• A/T selector lever
“N”
• Brake pedal de-
pressed4WD shift switch: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)0V
Except the above Battery voltage Te r m i n a lWire
colorItem Condition Data (Approx.)

TF-54
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS FOR SYSTEM
2.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-51, "
Power Supply Circuit for Transfer Control Unit"
.
OK or NG
OK >> GO TO 3.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Perform self-diagnosis with TCM again. Refer to TF-48, "
Self-Diagnosis Procedure".
Vehicle Speed Sensor (ABS)INFOID:0000000003532532
DIAGNOSTIC PROCEDURE
1.CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)
Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to BRC-26, "
CONSULT-II Func-
tion (ABS)".
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 2.
2.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to TF-35, "
Transfer Control Unit Input/Output Signal Ref-
erence Value".
OK or NG
OK >> GO TO 3.
NG >> Check transfer control unit pin terminals for damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
OK or NG
OK >> Inspection End.
NG >> Perform self-diagnosis with ABS actuator and electric unit (control unit) again. Refer to BRC-26,
"CONSULT-II Function (ABS)".
Neutral-4LO SwitchINFOID:0000000003532533
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Data are reference value.
TRANSFER CONTROL UNIT TERMINALS AND REFERENCE VALUE
Monitored item Content Condition Display value
N POSI SW TF [ON/
OFF]Condition of neutral-4LO
switch• Vehicle stopped
• Engine running
• A/T selector lever “N”
position
• Brake pedal depressed4WD shift switch: 2WD,
AUTO or 4HOFF
4WD shift switch: 4H to
4LO (While actuator mo-
tor is operating.)OFF → ON
4WD shift switch: 4LO to
4H (While actuator motor
is operating.)ON → OFF
4WD shift switch: 4LO ON