2004 INFINITI QX56 Can communication

RSU-1
REAR SUSPENSION
E SUSPENSION
CONTENTS
C
D
F
G
H
I
J
K
L
M
SECTION RSU
A
B
RSU
Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Precautions for Rear Suspension ............................ 3
Wiring Diagrams and Trouble Diagnosis .................. 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
WORK SUPPORT ............................................... 14
SELF-DIAGNOSIS .............................................. 14
DATA MONITOR ................................................. 15
ACTIVE TEST ..................................................... 16
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC
ITEMS ....................................................................... 17
Height Sensor System Inspection .......................... 17
Exhaust Valve Solenoid System Inspection ........... 19
Compressor Motor, Compressor Motor Relay and Circuit Inspection .................................................... 20
TROUBLE DIAGNOSES FOR SYMPTOMS ............ 23
Load Leveling Rear Air Suspension System Does
Not Operate ............................................................ 23
CK SUSP Indicator Lamp Stays On When Ignition
Switch Is Turned On ............................................... 24
REAR SUSPENSION ASSEMBLY ........................... 25
Components ........................................................... 25
On-Vehicle Inspection and Service ......................... 26
SHOCK ABSORBER INSPECTION .................... 26
Wheel Alignment Inspection ................................... 27
PRELIMINARY INSPECTION ............................. 27
GENERAL INFORMATION AND RECOMMEN-
DATIONS ............................................................. 27
THE ALIGNMENT PROCESS ............................. 28
CAMBER ............................................................. 28
TOE-IN ................................................................ 28
REAR SUSPENSION MEMBER ............................... 30
Removal and Installation ........................................ 30
REMOVAL ........................................................... 31
INSPECTION AFTER REMOVAL ....................... 32
INSTALLATION ................................................... 33
SHOCK ABSORBER ................................................ 34
Removal and Installation ........................................ 34
REMOVAL ........................................................... 34
INSTALLATION ................................................... 34
INSPECTION AFTER INSTALLATION ................ 34
SUSPENSION ARM .................................................. 35
Removal and Installation ........................................ 35
REMOVAL ........................................................... 35
INSPECTION AFTER REMOVAL ....................... 35
INSTALLATION ................................................... 36
FRONT LOWER LINK .............................................. 37
Removal and Installation ........................................ 37
REMOVAL ........................................................... 37
INSPECTION AFTER REMOVAL ....................... 37
INSTALLATION ................................................... 38

RSU-6
CAN COMMUNICATION
Revision: August 20072004 QX56
CAN COMMUNICATIONPFP:23710
System DescriptionEES00112
Refer to LAN-5, "CAN COMMUNICATION" .

TROUBLE DIAGNOSIS
RSU-13
C
D
F
G
H
I
J
K
L
MA
B
RSU
Revision: August 20072004 QX56
CONSULT-II Function (AIR LEVELIZER)EES00119
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II OPERATION
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.
1. Turn ignition switch OFF.
2. Connect CONSULT-II and CONSULT-II CONVERTER to the
data link connector.
3. Turn ignition switch ON.
4. Touch “START (NISSAN BASED VHCL)”.
5. Touch "AIR LEVELIZER" on the "SELECT SYSTEM" screen.
If "AIR LEVELIZER" is not indicated, go to GI-39, "
CONSULT-II
Data Link Connector (DLC) Circuit" .
AIR LEVELIZER
diagnostic modeDescription
WORK SUPPORTSupports inspections and adjustments. Commands are transmitted to the suspension control unit for
setting the status suitable for required operation, input/output signals are received from the suspen-
sion control unit and received data is displayed.
SELF-DIAG RESULTS Displays suspension control unit self-diagnosis results.
DATA MONITOR Displays suspension control unit input/output data in real time.
ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.
ECU PART NUMBER Suspension control unit part number can be read.
BBIA0369E
BCIA0029E
BCIA0030E

RSU-14
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
6. Select the required operation from the "SELECT DIAG MODE"
screen.
For further information, see the CONSULT-II Operation Manual.
WORK SUPPORT
Operation Procedure
1. Touch “AIR LEVELIZER” on “SELECT SYSTEM” screen.
2. Touch “WORK SUPPORT” on “SELECT DIAG MODE” screen.
3. Touch item on “SELECT WORK ITEM” screen.
4. Touch “START”.
5. The setting will be changed and “ADJUSTMENT COMPLETE” will be displayed.
6. Touch “END”.
Display Item List
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. After stopping the vehicle, with the engine running, touch “START (NISSAN BASED VHCL)”, "AIR LEVEL-
IZER", “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, "AIR LEVELIZER" might not be displayed in the "SELECT SYSTEM" screen. In
this case, repeat the operation from step 1.
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-39, "
CONSULT-II Data Link Connector (DLC) Circuit" .
BCIA0031E
Item Description
STANDARD HEIGHT LEVEL This mode allows the vehicle height to be set to vehicle height specification within tolerance.
ADJUST HEIGHT INI The initialization value and flag can be set in the suspension control unit in this mode.
CLEAR HEIGHT INI This mode clears the initialization flag and value in the suspension control unit.

TROUBLE DIAGNOSIS
RSU-15
C
D
F
G
H
I
J
K
L
MA
B
RSU
Revision: August 20072004 QX56
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
DATA MONITOR
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", “DATA MONITOR” in order on the CON-
SULT-II screen.
If "AIR LEVELIZER" 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, "AIR LEVELIZER" might not be displayed in the "SELECT SYSTEM" screen.
In this case, repeat the operation from step 2.
3. Return to the "SELECT MONITOR ITEM" screen, and touch "ALL SIGNALS" or "SELECTION FROM
MENU". Refer to the following information.
4. When “START” is touched, the data monitor screen is displayed.
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-17, "
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-20, "
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" .
Vehicle height adjusting trouble
(compressor)
[C1804]Continuous compressor relay ON time is more than 120 sec-
onds.Refer to RSU-20, "
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-17, "
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-17, "
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-20, "
Compres-
sor Motor, Compressor
Motor Relay and Circuit
Inspection" .

RSU-16
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Display Item List
X: Applicable
–: Not applicable
ACTIVE TEST
CAUTION:

Do not perform active test while driving.
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 "AIR LEVELIZER".
If "AIR LEVELIZER" is not indicated, go to GI-39, "
CONSULT-II Data Link Connector (DLC) Circuit" .
4. Touch “ACTIVE TEST”.
5. The "SELECT TEST ITEM" screen is displayed.
6. Touch necessary test item.
7. With the "MAIN SIGNALS" display highlighted, touch “START”.
8. The active test screen will be displayed.
Display Item List
CAUTION:
The "COMPRESSOR" active test will remain ON until it is turned off using CONSULT-II. Allowing the
compressor to run for an extended period of time may cause damage to air suspension system com-
ponents due to excessive pressure in the air suspension system.
NOTE:

“TEST IS STOPPED” is displayed approximately 10 seconds after operation starts for all active test items
except "COMPRESSOR".

After “TEST IS STOPPED” is displayed, to perform test again, repeat Step 6.
Te s t I t e mData monitor item selection
ALL
SIGNALSSELECTION
FROM MENU
HEIGT SENXX
HEIGT CALCXX
SEN FIX TIMEXX
HEIGT INI VALXX
COMPRESSOR X X
EXH SOLENOID X X
ACG LXX
Test Item Description
COMPRESSOROFF/ON
EXHAUST SOLENOIDOFF/ON
WARNING LAMPOFF/ON

SE-1
SEAT
I BODY
CONTENTS
C
D
E
F
G
H
J
K
L
M
SECTION SE
A
B
SE
Revision: August 20072004 QX56 PRECAUTIONS .......................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Precautions for Work ................................................ 3
PREPARATION ........................................................... 4
Special Service Tool ................................................. 4
Commercial Service Tool ......................................... 4
SQUEAK AND RATTLE TROUBLE DIAGNOSES ..... 5
Work Flow ................................................................ 5
CUSTOMER INTERVIEW ..................................... 5
DUPLICATE THE NOISE AND TEST DRIVE ....... 6
CHECK RELATED SERVICE BULLETINS ........... 6
LOCATE THE NOISE AND IDENTIFY THE
ROOT CAUSE ...................................................... 6
REPAIR THE CAUSE ........................................... 6
CONFIRM THE REPAIR ....................................... 7
Generic Squeak and Rattle Troubleshooting ........... 7
INSTRUMENT PANEL .......................................... 7
CENTER CONSOLE ............................................. 7
DOORS ................................................................. 7
TRUNK .................................................................. 8
SUNROOF/HEADLINER ....................................... 8
OVERHEAD CONSOLE (FRONT AND REAR) ..... 8
SEATS .................................................................. 8
UNDERHOOD ....................................................... 8
Diagnostic Worksheet .............................................. 9
AUTOMATIC DRIVE POSITIONER ...........................11
Component Parts And Harness Connector Location
....11
Manual Operation ................................................... 12
Automatic Operation .............................................. 12
System Description ................................................ 12
FAIL-SAFE MODE .............................................. 13
CANCEL OF FAIL-SAFE MODE ......................... 13
MEMORY STORING AND KEYFOB INTER-
LOCK STORING ................................................. 14
MEMORY OPERATION ...................................... 15
ENTRY OPERATION .......................................... 15
EXITING OPERATION ........................................ 15KEYFOB INTERLOCK OPERATION .................. 16
CAN Communication System Description .............. 16
Schematic ............................................................... 17
Wiring Diagram — AUT/DP — ............................... 19
Terminals and Reference Values for BCM .............. 29
Terminals and Reference Values for Driver Seat
Control Unit ............................................................. 29
Terminals and Reference Values for Automatic
Drive Positioner Control Unit .................................. 31
Work Flow ............................................................... 33
Preliminary Check .................................................. 34
SETTING CHANGE FUNCTION ......................... 34
POWER SUPPLY AND GROUND CIRCUIT
INSPECTION ...................................................... 34
CONSULT-II Function (AUTO DRIVE POS.) .......... 37
CONSULT-II INSPECTION PROCEDURE .......... 37
SELF-DIAGNOSIS RESULTS ............................. 39
DATA MONITOR ................................................. 40
ACTIVE TEST ..................................................... 41
CAN Communication Inspection Using CONSULT-
II (Self-Diagnosis) ................................................... 41
Symptom Chart ....................................................... 41
Sliding Motor Circuit Inspection .............................. 43
Reclining Motor LH Circuit Inspection .................... 44
Lifting Motor (Front) Circuit Inspection ................... 46
Lifting Motor (Rear) Circuit Inspection .................... 47
Pedal Adjusting Motor Circuit Inspection ................ 49
Mirror Motor LH Circuit Check ................................ 50
Mirror Motor RH Circuit Check ............................... 52
Steering Wheel Tilt Circuit Inspection ..................... 53
Sliding Sensor Circuit Inspection ............................ 55
Reclining Sensor Circuit Inspection ........................ 56
Lifting Sensor (Front) Circuit Inspection ................. 57
Lifting Sensor (Rear) Circuit Inspection .................. 58
Pedal Adjusting Sensor Circuit Inspection .............. 59
Mirror Sensor LH Circuit Check .............................. 60
Mirror Sensor RH Circuit Check ............................. 62
Steering Wheel Tilt Sensor Circuit Inspection ........ 64
Sliding Switch Circuit Inspection ............................. 66
Reclining Switch Inspection .................................... 67

AUTOMATIC DRIVE POSITIONER
SE-13
C
D
E
F
G
H
J
K
L
MA
B
SE
Revision: August 20072004 QX56

The settings (ON/OFF) of the automatic sliding seat (Entry/Exiting operation) at entry/exit can be changed
as desired, using the display unit in the center of the instrument panel. The set content is transmitted by
CAN communication, from display control unit to driver seat control unit.

Using CONSULT-ll, the seat slide amount at entry/exit setting can be changed.
FAIL-SAFE MODE
When any manual and automatic operations are not performed, if any motor operations of seats or pedals are
detected for T2 or more, status is judged “Output error”.
CANCEL OF FAIL-SAFE MODE
The mode is cancelled when the selector lever is shifted to P position from any other position.
OPERATED PORTION T2
Seat sliding Approx. 0.1 sec.
Seat reclining Same as above
Seat lifting (Front) Same as above
Seat lifting (Rear) Same as above
Steering wheel Same as above
Pedal adjust Same as above