ECU INFINITI QX56 2008 Factory Service Manual

SCS-2
EXHAUST VALVE SOLENOID CIRCUIT ..........23
Description ........................................................... ...23
Component Function Check ...................................23
Diagnosis Procedure ..............................................23
CK SUSP WARNING INDICATOR CONTROL
CIRCUIT .............................................................
25
Description ........................................................... ...25
Component Function Check ...................................25
Diagnosis Procedure ..............................................25
ECU DIAGNOSIS ..................................... ...27
SUSPENSION CONTROL UNIT ........................27
Reference Value .................................................. ...27
Wiring Diagram .......................................................28
DTC Index ..............................................................33
SYMPTOM DIAGNOSIS .............................35
SUSPENSION CONTROL SYSTEM .............. ...35
Symptom Table ................................................... ...35
SUSPENSION CONTROL SYSTEM INOPER-
ATIVE .................................................................
36
Description ........................................................... ...36
Diagnosis Procedure ...............................................36
SUSPENSION CONTROL SYSTEM DOES
NOT RAISE ........................................................
37
Description ........................................................... ...37
Diagnosis Procedure ...............................................37
SUSPENSION CONTROL SYSTEM DOES
NOT LOWER .....................................................
38
Description ........................................................... ...38
Diagnosis Procedure ...............................................38
PRECAUTION ............................................39
PRECAUTIONS .............................................. ...39
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. ...
39
Precaution for Rear Suspension .............................39
Revision: March 2010 2008 QX56

DIAGNOSIS SYSTEM (SUSPENSION CONTROL UNIT)
SCS-7
< FUNCTION DIAGNOSIS >
C
D F
G H
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M A
B
SCS
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DIAGNOSIS SYSTEM (SUS PENSION CONTROL UNIT)
CONSULT-III FunctionINFOID:0000000001731959
CONSULT-III can display each diagnostic item using the diagnostic test modes shown following.
WORK SUPPORT
Display Item List
SELF-DIAG RESULTS
Display Item List
Refer to SCS-33, "DTC Index".
DATA MONITOR
Display Item List
ACTIVE TEST
CAUTION:
Do not perform active test while driving.
Display Item List
AIR LEVELIZER diagno sis mode Description
WORK SUPPORT Supports inspection and adjustment. Commands are transmitted to the suspension control
unit for setting the status suitable for required operation, input/output signals are received
from the suspension 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 The part number of suspension control unit can be checked.
ItemDescription Condition
STANDARD HEIGHT LEVEL Resets the vehicle height to the initialization flag
setting stored in the suspension control unit. Vehicle unladen, set in a horizontal position and
not moving.
NOTE:
Do not take your eyes off the vehicle while CON-
SULT-III is processing.
ADJUST HEIGHT INI Sets the height initialization flag in the suspen-
sion control unit when the control unit has been
replaced or when the initialization flag has been
cleared using the "CLEAR HEIGHT INI" proce-
dure. Vehicle unladen, move vehicle forward and back-
ward approx. 5 m (16.4 ft) and rock vehicle side
to side.
NOTE:
Do not move vehicle wh
ile CONSULT-III is pro-
cessing.
CLEAR HEIGHT INI Clears the initialization flag in the suspension
control unit. Vehicle unladen.
Display item [unit]
ALL
SIGNALS SELECTION FROM MENU
HEIGT SEN [V] XX
HEIGT CALC [mm] XX
SEN FIX TIME [HR] XX
HEIGT INI VAL [V] XX
COMPRESSOR [ON/OFF] XX
EXH SOLENOID [ON/OFF] XX
ACG L [ON/OFF] XX
Revision: March 2010 2008 QX56

SUSPENSION CONTROL UNITSCS-27
< ECU DIAGNOSIS >
C
DF
G H
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M A
B
SCS
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ECU DIAGNOSIS
SUSPENSION CONTROL UNIT
Reference ValueINFOID:0000000001731999
TERMINAL LAYOUT
PHYSICAL VALUES
ALNIA0660GB
Te r m i n a l
(Wire color) Description
ConditionReference value
(Approx.)
+ – Signal nameInput/
Output
1
(V) Ground Compressor relay output Output Ignition
switch
ON Air levelizer ra
ising vehicle
ride height Battery voltage
3
(W) Ground Height sensor input
InputIgnition
switch ON —
0.2V - 4.8V
5
(R) Ground VREF output (height sen-
sor) OutputIgnition
switch ON —5
V
6
(G/R) Ground IGN power supply
InputIgnition
switch
ON or
START —
Battery voltage
7
(W/L) Ground BAT power supply
InputIgnition
switch
OFF —
Battery voltage
8
(G/W) Ground Diagnostic K-line Input/
Output ——
—
9
(SB) Ground Exhaust valve output Output Ignition
switch ON Air levelizer lo
wering vehi-
cle ride height (venting) Battery voltage
10
(BR) Ground Warning lamp output Output Ignition
switch ON Warning lamp ON
0V
Warning lamp OFF Battery voltage
14
(L) Ground Height sensor ground Output Ignition
switch
ON —
Less than 0.2V
15
(BR/W) Ground Generator input
InputIgnition
switch ON Charge light ON
0V
Charge light OFF Battery voltage
16
(B) Ground Suspension control unit
ground InputIgnition
switch ON —
Less than 0.2V
Revision: March 2010 2008 QX56

SCS-28
< ECU DIAGNOSIS >
SUSPENSION CONTROL UNIT
Wiring Diagram
INFOID:0000000001732000
AAEWA0003GB
Revision: March 2010 2008 QX56

SUSPENSION CONTROL UNITSCS-29
< ECU DIAGNOSIS >
C
DF
G H
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M A
B
SCS
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AAEIA0012GB
Revision: March 2010 2008 QX56

SCS-30
< ECU DIAGNOSIS >
SUSPENSION CONTROL UNIT
ALEIA0018GB
Revision: March 20102008 QX56

SUSPENSION CONTROL UNITSCS-31
< ECU DIAGNOSIS >
C
DF
G H
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K L
M A
B
SCS
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ALEIA0019GB
Revision: March 2010 2008 QX56

SCS-32
< ECU DIAGNOSIS >
SUSPENSION CONTROL UNIT
ALEIA0020GB
Revision: March 20102008 QX56

SUSPENSION CONTROL UNITSCS-33
< ECU DIAGNOSIS >
C
DF
G H
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M A
B
SCS
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DTC IndexINFOID:0000000001732001
Self-diagnosis results display item
ALEIA0043GB
CONSULT-III display MalfunctionReference page
Vehicle height sensor [C1801] Vehicle height sensor voltage is less than 0.2V or greater than
4.8V for more than 60 seconds. SCS-9,
"DiagnosisProcedure"
Revision: March 2010
2008 QX56

SCS-34
< ECU DIAGNOSIS >
SUSPENSION CONTROL UNIT
Compressor relay [C1802]• Driving transistor for compre
ssor relay is OFF and monitor
voltage continues at a high level for more than 10 seconds.
• Driving transistor for compressor relay is ON and monitor volt-
age continues at a low level for more than 5 seconds. SCS-10, "DiagnosisProcedure"
Exhaust solenoid [C1803]
• Driving transistor for exhaust valve solenoid is OFF and mon-
itor voltage continues at a high level for more than 10 seconds.
• Driving transistor for exhaust valve solenoid is ON and monitor voltage continues at a low level for more than 5 secondsl. SCS-11, "DiagnosisProcedure"
Vehicle height adjusting malfunction
(compressor)[C1804]
Continuous compressor relay ON time is more than 120 sec-
onds. SCS-12,
"DiagnosisProcedure"
Vehicle height adjusting malfunction
(exhaust solenoid)[C1805]Continuous exhaust valve solenoid ON time is more than 120
seconds. SCS-13,
"DiagnosisProcedure"
Vehicle height sensor locking mal-
function [C1806]Output sensor voltage variation
±0.02V is more than 100 sec-
onds when vehicle height range is normal. SCS-14, "Diagnosis Pro-
cedure"
Sensor 5V malfunction [C1807]
Sensor reference voltage is less than 0.8V or more than 6V for
20 seconds. SCS-15, "DiagnosisProcedure"
Integral time malfunction by supply-
ing air [C1808]A suspension air compressor ON request has been in effect for
180 seconds and the suspension air compressor has not activat-
ed during that time. SCS-16,
"DiagnosisProcedure"
Revision: March 2010
2008 QX56