2006 INFINITI QX56 relay

RSU-1
REAR SUSPENSION
E SUSPENSION
CONTENTS
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Revision: November 2009 2006 QX56
PRECAUTIONS .....................................................
..... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” ............................................................. ..... 3
Precautions for Rear Suspension ....................... ..... 3
PREPARATION ...................................................... ..... 4
Commercial Service Tools ................................... ..... 4
NOISE, VIBRATION, AND HARSHNESS (NVH)
TROUBLESHOOTING ........................................... ..... 5
NVH Troubleshooting Chart ................................ ..... 5
CAN COMMUNICATION ....................................... ..... 6
System Description ............................................. ..... 6
TROUBLE DIAGNOSIS ......................................... ..... 7
How to Perform Trouble Diagnoses for Quick and
Accurate Repair .................................................. ..... 7
INTRODUCTION .............................................. ..... 7
CLARIFY CONCERN ....................................... ..... 7
WORK FLOW ........................................................ 8
Component Parts and Harness Connector Location ..... 9
Wiring Diagram — A/SUSP — ............................ ... 10
Basic Inspection .................................................. ... 12
AIR HOSES ...................................................... ... 12
POWER SYSTEM TERMINAL LOOSENESS
AND BATTERY INSPECTION ......................... ... 12
CK SUSP INDICATOR LAMP INSPECTION ... ... 12
CK SUSP Indicator Lamp Timing ........................ ... 12
Control Unit Input/Output Signal Standard .......... ... 12
CONSULT-II Function (AIR LEVELIZER) ............ ... 13
CONSULT-II OPERATION ............................... ... 13
SELF-DIAGNOSIS ........................................... ... 14
WORK SUPPORT ............................................ ... 15
DATA MONITOR .............................................. ... 16
ACTIVE TEST .................................................. ... 16
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS .................................................................... ... 18
Height Sensor System Inspection ....................... ... 18
Exhaust Valve Solenoid System Inspection ........ ... 19
Compressor Motor, Compressor Motor Relay and
Circuit Inspection ................................................. ... 21
TROUBLE DIAGNOSES FOR SYMPTOMS ......... ... 24Load Leveling Rear Air Suspension System Does
Not Operate ............................................................ 24
CK SUSP Indicator Lamp Stays On When Ignition
Switch Is Turned On ............................................
... 25
REAR SUSPENSION ASSEMBLY ........................... 26 Components ........................................................ ... 26
On-Vehicle Inspection and Service ...................... ... 27
SHOCK ABSORBER INSPECTION ................. ... 27
Wheel Alignment Inspection ................................ ... 28
PRELIMINARY INSPECTION .......................... ... 28
GENERAL INFORMATION AND RECOMMEN-
DATIONS .......................................................... ... 28
THE ALIGNMENT PROCESS .......................... ... 29
CAMBER .......................................................... ... 29
TOE-IN ............................................................. ... 29
REAR SUSPENSION MEMBER ............................... 31 Removal and Installation ..................................... ... 31
REMOVAL ........................................................ ... 32
INSPECTION AFTER REMOVAL .................... ... 33
INSTALLATION ................................................ ... 34
SHOCK ABSORBER ............................................. ... 35
Removal and Installation ..................................... ... 35
REMOVAL ........................................................ ... 35
INSTALLATION ................................................ ... 35
INSPECTION AFTER INSTALLATION ............. ... 35
SUSPENSION ARM ............................................... ... 36
Removal and Installation ..................................... ... 36
REMOVAL ........................................................ ... 36
INSPECTION AFTER REMOVAL .................... ... 36
INSTALLATION ................................................ ... 37
FRONT LOWER LINK ........................................... ... 38
Removal and Installation ..................................... ... 38
REMOVAL ........................................................ ... 38
INSPECTION AFTER REMOVAL .................... ... 38
INSTALLATION ................................................ ... 39
REAR LOWER LINK & COIL SPRING .................. ... 40
Removal and Installation ..................................... ... 40
REMOVAL ........................................................ ... 40
INSPECTION AFTER REMOVAL .................... ... 41
INSTALLATION ................................................ ... 41

RSU-12
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
Basic InspectionEES001H6
AIR HOSES
1. Check for pinched or damaged air hoses between the suspension air reservoir and each load leveling rear
air suspension shock absorber. Reposition, repair or replace hoses as necessary.
2. Check the air hose connections at the suspension air reservoir and at the shock absorbers for leaks. If connections are leaking, repair or replace hoses as necessary.
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.
CK SUSP INDICATOR LAMP INSPECTION
1. Make sure the CK SUSP indicator lamp turns on for approximately 2 seconds when the ignition switch is
turned ON. If it does not, check the combination meter. Refer to DI-5, "
COMBINATION METERS" .
2. Make sure the lamp turns off approximately 2 seconds after the ignition switch is turned ON. If the lamp does not turn off, conduct self-diagnosis of the suspension control unit.
3. After conducting the self-diagnosis, be sure to erase the error memory. Refer to RSU-13, "
CONSULT-II
Function (AIR LEVELIZER)" .
CK SUSP Indicator Lamp TimingEES001H7
X: ON
—: OFF
Control Unit Input/Output Signal StandardEES001H8
ConditionCK SUSP
indicator lamp Remarks
Ignition switch OFF ––
Ignition switch ON X Turns off after approximately 2 seconds.
Te r m i n a l
No. Wire color
Item ConditionVoltage (V)
(Approx.)
1 V Compressor relay output
Ignition switch ON or STARTBattery voltage
3 W Height sensor signal input 0.2V - 4.8V
5 R Reference voltage 5V
6 G/R Ignition power
Battery voltage
7W /LB atte ry p ow er —
8 G/W Diagnostic K-line ——
9 SB Exhaust valve output Ignition switch ON or STARTBattery voltage
10 BR Warning lamp output ——
14 L Height sensor ground ——
15 BR/W Generator L signal input Engine running—
16 B Suspension control unit ground —0V

RSU-14
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
6. Select the required operation 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, 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. With the engine running, touch "START (NISSAN BASED VHCL)", "AIR LEVELIZER", "SELF-DIAG RESULTS" in order on the CONSULT-II screen.
CAUTION:
When "START (NISSAN BASED VHCL)" is touched immediately after starting the engine or turning
on the ignition switch, "AIR LEVELIZER" might not be displayed in the "SELECT SYSTEM" screen.
In this case, repeat the operation from step 4.
5. The self-diagnostic results are displayed. (If necessary, the self-diagnostic results can be printed out by touching "COPY".)

When "NO DTC IS DETECTED" is displayed, check the CK SUSP indicator lamp.
6. Conduct the appropriate inspection from the display item list, and repair or replace the malfunctioning component.
7. Start and run the vehicle for approximately 1 minute.
8. Turn ignition switch OFF to prepare for erasing the memory.
9. Start the engine and touch "START (NISSAN BASED VHCL)", "AIR LEVELIZER", "SELF-DIAG RESULTS", "ERASE" in order on the CONSULT-II screen to erase the error memory.
If "AIR LEVELIZER" is not indicated, go to GI-40, "
CONSULT-II Data Link Connector (DLC) Circuit" .
CAUTION:
If the error memory is not erased, re-conduct the operation from step 7.
10. For the final inspection, start and run the vehicle for approximately 1 minute and confirm that the CK SUSP indicator lamp is off.
Display Item List
BCIA0031E
Self-diagnostic item Malfunction detecting condition Check system
Vehicle height sensor
[C1801] Vehicle height sensor voltage is less than 0.2V or greater than
4.8V for more than 60 seconds. Refer to
RSU-18, "
Height
Sensor System Inspection" .
Compressor relay
[C1802] 1. Driving transistor for compressor relay is off and monitor volt-
age continues high level for more than 10 seconds.
2. Driving transistor for compressor relay is on and monitor volt- age continues low level for more than 5 seconds. Refer to
RSU-21, "
Compres-
sor Motor, Compressor
Motor Relay and Circuit
Inspection" .
Exhaust solenoid
[C1803] 1. Driving transistor for exhaust solenoid is off and monitor volt-
age continues high level for more than 10 seconds.
2. Driving transistor for exhaust solenoid is on and monitor volt- age continues low level for more than 5 seconds. Refer to
RSU-19, "
Exhaust
Valve Solenoid System
Inspection" .

TROUBLE DIAGNOSISRSU-15
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Revision: November 2009 2006 QX56
WORK SUPPORT
Operation Procedure
1. After turning OFF the ignition switch, connect CONSULT-II and the 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.
2. Touch "START (NISSAN BASED VHCL)", "AIR LEVELIZER", "WORK SUPPORT" in order on the CON- SULT-II screen.
If "AIR LEVELIZER" is not indicated, go to GI-40, "
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, "AIR LEVELIZER" might not be displayed in the "SELECT SYSTEM" screen.
In this case, repeat the operation from step 2.
3. Select "STANDARD HEIGHT LEVEL", "ADJUST HEIGHT INI" or "CLEAR HEIGHT INI" on the "SELECT WORK ITEM" screen.
NOTE:
Read and perform screen instructions if "STANDARD HEIGHT LEVEL" or "ADJUST HEIGHT INI" is
selected.
4. Touch "START" to begin the desired work support.
Display Item List
Vehicle height adjusting trouble
(compressor)
[C1804] Continuous compressor relay ON time is more than 120 sec-
onds. Refer to
RSU-21, "Compres-
sor Motor, Compressor
Motor Relay and Circuit
Inspection" .
Vehicle height adjusting trouble
(exhaust solenoid)
[C1805] Continuous exhaust solenoid ON time is more than 120 seconds. Refer to
RSU-19, "
Exhaust
Valve Solenoid System
Inspection" .
Vehicle height sensor locking trou-
ble
[C1806] Output sensor voltage variation ±
0.02V is more than 100 hour
when vehicle height range is normal. Refer to
RSU-18, "
Height
Sensor System Inspection" .
Sensor 5V trouble
[C1807] Sensor reference voltage is less than 0.8V or more than 6V for
20 seconds. Refer to
RSU-18, "
Height
Sensor System Inspection" .
Integral time trouble by supplying
air
[C1808] Integral discontinuous time on the compressor is more than 180
seconds. Refer to
RSU-21, "
Compres-
sor Motor, Compressor
Motor Relay and Circuit
Inspection" .
Self-diagnostic item
Malfunction detecting condition Check system
ItemDescription Condition
STANDARD HEIGHT LEVEL Resets the vehicle height to the initialization flag
setting stored in the suspension control unit. Vehicle unladen
RSU-49, "
Wheelarch Height
(Unladen*1 )" , set in a horizontal position and
not moving.
NOTE:
Do not take your eyes off the vehicle while
CONSULT-II is processing.
ADJUST HEIGHT INI Sets the height initialization flag in the suspension
control unit when the control unit has been replaced
or when the initialization flag has been cleared
using the "CLEAR HEIGHT INI" procedure. Vehicle unladen
RSU-49, "
Wheelarch Height
(Unladen*1 )" . Move vehicle forward and
backward approx. 5 m (16.4 ft) and rock vehi-
cle from side to side.
NOTE:
Do not move vehicle while CONSULT-II is pro-
cessing.
CLEAR HEIGHT INI Clears the initialization flag in the suspension con-
trol unit. Vehicle unladen
RSU-49, "
Wheelarch Height
(Unladen*1 )" .

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMSRSU-21
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Revision: November 2009 2006 QX56
6. CHECK EXHAUST VALVE SOLENOID POWER AND GROUND
1. Reconnect the suspension control unit connector.
2. Turn the ignition switch ON.
3. Check voltage between suspension air compressor connector C9 terminal 2 and ground.
4. Turn ignition switch OFF.
5. Check continuity between suspension air compressor connector C9 terminal 1 and ground.
OK or NG
OK >> Replace the suspension control unit. Refer to RSU-47,
"CONTROL UNIT" .
NG >> Repair harness or connector.
Compressor Motor, Compressor Motor Relay and Circuit InspectionEES001HC
INSPECTION PROCEDURE
1. SELF-DIAGNOSIS RESULT CHECK
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES >> If code C1802 was retrieved during self-diagnosis, GO TO 3. If code C1804 or C1808 was retrieved during self-diagnosis, GO TO 2.
NO >> Inspection End.
2. CHECK SYSTEM OPERATION
1. Load vehicle to standard laden condition (with driver, front passenger, 2 passengers in second row seats and no cargo).
2. Conduct active test of "EXHAUST SOLENOID" to lower vehicle ride height to -20mm.
3. Return the rear load leveling air suspension system to normal operating mode.
4. Check self-diagnostic results.
Is code C1804 or C1808 displayed again?
YES >> GO TO 3.
NO >> Inspection End. Voltage
: Approx. 12V
WEIA0088E
1 - GroundContinuity should exist.
WEIA0089E
Self-diagnosis results
C1802
C1804
C1808

RSU-24
TROUBLE DIAGNOSES FOR SYMPTOMS
Revision: November 20092006 QX56
TROUBLE DIAGNOSES FOR SYMPTOMSPFP:99999
Load Leveling Rear Air Suspension System Does Not OperateEES001HD
1. CHECK WARNING LAMP ACTIVATION
Make sure warning lamp remains off while driving.
OK or NG
OK >> GO TO 2.
NG >> Carry out self-diagnosis. Refer to RSU-14, "
SELF-DIAGNOSIS" .
2. CHECK FUSES AND FUSIBLE LINK
Check that the following fuses and fusible link are not blown.
OK or NG
OK >> GO TO 3.
NG >> If fuse or fusible link is blown, be sure to eliminate cause of malfunction before installing new fuse or fusible link. Refer to PG-4, "
POWER SUPPLY ROUTING CIRCUIT" .
3. CHECK SUSPENSION CONTROL UNIT POWER AND GROUND
1. Turn the ignition switch ON.
2. Check voltage between suspension control unit connector B3 terminal 6 and ground and between suspension control unit con-
nector B3 terminal 7 and ground.
3. Turn the ignition switch OFF.
4. Check continuity between suspension control unit connector B3 terminal 16 and ground.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
Unit Terminals Signal nameFuse and fusible link No.
Suspension control unit 6
Ignition switch ON or START 12 (10A)
7 Battery power 29 (10A)
Compressor motor relay 5 g (30A)
Combination meter 24
Ignition switch ON or START 14 (10A)
8 Battery power 19 (10A)
Voltage: Approx. 12V
WEIA0069E
16 - Ground Continuity should exist.
WEIA0070E

SC-10
STARTING SYSTEM
Revision: November 20092006 QX56
STARTING SYSTEMPFP:23300
System DescriptionEKS00B7B
Power is supplied at all times:

through 40A fusible link (letter m , located in the fuse and fusible link box)

to ignition switch terminal B.
With the ignition switch in the START position, power is supplied:

from ignition switch terminal ST

to IPDM E/R terminal 21.
With the ignition switch in the ON or START position, power is supplied to IPDM E/R (intelligent power distribu-
tion module engine room) CPU.
With the selector lever in the P or N position, power is supplied:

through A/T assembly terminal 9

to IPDM E/R terminal 48.
Ground is supplied at all times:

to IPDM E/R terminals 38 and 59

through body grounds E9, E15 and E24.
Then the starter relay is turned on.
The IPDM E/R is energized and power is supplied:

from terminal 19 of the IPDM E/R

to terminal 1 of the starter motor windings.
The starter motor plunger closes and provides a closed circuit between the battery and the starter motor. The
starter motor is grounded to the cylinder block. With power and ground supplied, the starter motor operates.

STARTING SYSTEMSC-15
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Revision: November 2009 2006 QX56
DIAGNOSTIC PROCEDURE 2
Check Magnetic Switch Circuit
1. CHECK POWER SUPPLY FOR MAGNETIC SWITCH
1. Remove the fuel pump fuse.
2. Crank or start the engine (where possible) until the fuel pressure is released.
3. Turn the ignition switch OFF.
4. Disconnect starter motor connector F28.
5. Check voltage between starter motor connector F28 terminal 1 and ground using a digital circuit tester.
OK or NG
OK >> GO TO 2.
NG >> Check the following.

40A fusible link (letter m , located in fuse and fusible
link box)

Ignition switch

Starter relay [within the intelligent power distribution module engine room (IPDM E/R)]

Harness for open or short
2. CHECK VOLTAGE DROP ON MAGNETIC SWITCH CIRCUIT
1. Turn the ignition switch OFF.
2. Connect starter motor connector F28.
3. Check voltage between starter motor connector F28 terminal 1 and battery positive terminal using a digital circuit tester.
OK or NG
OK >> Magnetic switch circuit is OK. Further inspection is nec- essary. Refer to SC-13, "
WORK FLOW" .
NG >> Check harness between the battery and the magnetic
switch for poor continuity.
Ignition switch in
START.
: Battery voltage
WKIA2108E
Ignition switch in
START. : Less than 1V
WKIA1792E