Infiniti QX56 (JA60). Manual - part 810

SUSPENSION CONTROL SYSTEM

SCS-5

< FUNCTION DIAGNOSIS >

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FUNCTION DIAGNOSIS

SUSPENSION CONTROL SYSTEM

System Diagram

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System Description

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SUSPENSION CONTROL SYSTEM

The suspension control system consists of the following components

• Suspension control unit

• Compressor motor relay

• Suspension air compressor

• Exhaust valve solenoid (built into suspension air compressor)

• Height sensor

The suspension control unit monitors vehicle ride height as indicated by the height sensor. The suspension

control unit actuates the compressor motor relay to raise the vehicle ride height.  The suspension control unit

actuates the exhaust valve solenoid to lower the vehicle ride height.  

CK SUSP INDICATOR LAMP

The CK SUSP indicator lamp ground is controlled by the suspension control unit.  The indicator lamp will come

on for 2 seconds when the ignition switch is turned ON.  If the indicator lamp does not turn OFF there is a fault

detected.  Refer to 

SCS-7, "CONSULT-III Function"

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ALEIA0042GB

SCS-6

< FUNCTION DIAGNOSIS >

SUSPENSION CONTROL SYSTEM

Component Parts Location

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 :Front

Component Description

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1.

Suspension control unit B3 (view with 
upper and lower luggage side finishers 
LH removed)

2.

Suspension air compressor C9 (view 
under vehicle behind LH rear suspen-
sion)

3.

Height sensor C8 (view under vehicle 
at LH rear suspension)

4.

Compressor motor relay E130, E131 
(view with battery removed)

ALEIA0044ZZ

Part name

Description

Suspension control unit

• Monitors height sensor input to determine vehicle height.  
• Actuates the compressor motor relay or exhaust valve solenoid to raise or 

lower the vehicle accordingly.

• Sends a ground signal to the combination meter to activate the CK SUSP 

indicator lamp. 

Suspension air compressor (with built in exhaust valve 
solenoid)

• When the compressor is actuated, it pumps air into the system to raise the 

rear suspension.

• When the exhaust valve solenoid is actuated, it vents air from the system 

to lower the rear suspension. 

Height sensor

Provides vehicle height input to the suspension control unit.

DIAGNOSIS SYSTEM (SUSPENSION CONTROL UNIT)

SCS-7

< FUNCTION DIAGNOSIS >

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DIAGNOSIS SYSTEM (SUSPENSION CONTROL UNIT)

CONSULT-III Function

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CONSULT-III can display each diagnostic item using the diagnostic test modes shown following.

WORK SUPPORT

Display Item List

DATA MONITOR

Display Item List

ACTIVE TEST

CAUTION:

Do not perform active test while driving.

Display Item List

AIR LEVELIZER diagnosis 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.

Item

Description

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 while 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]

X

X

HEIGT CALC [mm]

X

X

SEN FIX TIME [HR]

X

X

HEIGT INI VAL [V]

X

X

COMPRESSOR [ON/OFF]

X

X

EXH SOLENOID [ON/OFF]

X

X

ACG L [ON/OFF]

X

X

Test Item

Description

COMPRESSOR

ON/OFF

SCS-8

< FUNCTION DIAGNOSIS >

DIAGNOSIS SYSTEM (SUSPENSION CONTROL UNIT)

CAUTION:

The "COMPRESSOR active test will remain ON until it is turned off using CONSULT-III. Allowing the

compressor to run for an extended period of time may cause damage to the suspension control sys-

tem components due to excessive pressure. 

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.

EXHAUST SOLENOID

ON/OFF

WARNING LAMP

ON/OFF