2011 INFINITI QX56 ECO mode

U1000 CAN COMM CIRCUITSBC-35
< DTC/CIRCUIT DIAGNOSIS >
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U1000 CAN COMM CIRCUIT
DescriptionINFOID:0000000006237897
 CAN (Controller Area Network) is a serial communica tion line for real time applications. It is an on board
multiplex communication line with high data communication speed and excellent error detection ability. A
modern vehicle is equipped with many ECMs, and each cont rol unit shares information and links with other
control units during operation (not independent). In CA N communication, two control units are connected
with two communication lines (CAN H-line, CAN L-line) allowing a high rate of information transmission with
less wiring. Each control unit transmits/receive s data but selectively reads required data only.
 It transmits the vehicle status to pre-crash seat belt control unit using the CAN communication system.
 It consists of CAN system (unified meter and A/ C amp., ICC sensor, BCM, steering angle sensor).
 Refer to LAN-27, "
CAN COMMUNICATION SYSTEM : CA N System Specification Chart".
DTC LogicINFOID:0000000006237898
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.SELF-DIAGNOSIS WITH PRE-CRASH SEAT BELT CONTROL UNIT
1. Turn ignition switch ON and wait for 2 seconds or more.
2. Check “Self-diagnostic result” with CONSULT-III.
Is any DTC detected?
YES >> Refer to LAN-27, "CAN COMMUNICATION SYSTEM : CA N System Specification Chart".
NO >> CAN communication system is normal.
DTC No. Self-diagnosis item DTC Detection Condition Possible causes
U1000 CAN communication
circuit Pre-crash seat belt control unit cannot transmit and re-
ceive CAN communication system for 2 seconds or
more.  Harness or connectors
(CAN communication line is open
or shorted)
Revision: 2010 May2011 QX56

COMPONENT PARTSSCS-51
< SYSTEM DESCRIPTION > [AIR LEVELIZER CONTROL SYSTEM]
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Air Levelizer Control ModuleINFOID:0000000006256042
 Operates ON/OFF of air compressor (exhaust solenoid) , according to signal from vehicle height sensor.
 Transmits CK SUSP indicator lamp signal to the combination meter via CAN communication, when setting of standard vehicle height is incomplete.
 If malfunction is detected, the syste m enters fail-safe mode. Refer to SCS-59, "
Fail-safe".
Vehicle Height SensorINFOID:0000000006256043
Measures vehicle height of vehicle rear and transmits th is information to air levelizer control module according
to electric signal.
Air CompressorINFOID:0000000006256044
Operates according to signal from air levelizer control module via air compressor relay, and charges air in air
chamber of rear shock absorber.
EXHAUST SOLENOID
Operates according to signal from air levelizer control module, and discharges air in air chamber of rear shock
absorber.
Air Compressor RelayINFOID:0000000006256045
Turns ON according to signal from air levelizer control module, and operates air compressor.
CK SUSP Indicator LampINFOID:0000000006256046
 Turns ON for 2 seconds when ignition switch is turned ON, for the purpose of bulb check.
 Turns ON when setting of standard vehicle height is incomplete.
NOTE:
Does not turn ON when the system is malfunctioning.
Air compressor relay SCS-51, "Air Compressor Relay"
CK SUSP indicator lampSCS-51, "CK SUSP Indicator Lamp"
Component parts Reference
Revision: 2010 May2011 QX56

SCS-54
< SYSTEM DESCRIPTION >[AIR LEVELIZER CONTROL SYSTEM]
SYSTEM
SYSTEM
System DiagramINFOID:0000000006256049
System DescriptionINFOID:0000000006256050
 Based on the signal from the vehicle height sensor, t
he air levelizer control module operates the air com-
pressor (exhaust solenoid) and controls vehicle height so that it remains at a constant height. This operation
occurs if vehicle height of vehicle rear is judged to be 15 mm (0.59 in) or more or 15 mm (0.59 in) or less
than standard vehicle height, continuously for 30 seconds, when engine is started.
 If malfunction is detected, the system enters fail-safe mode. Refer to SCS-59, "
Fail-safe".
INPUT/OUTPUT SIGNAL
Air levelizer control module transmits and receives following signals between each control unit via CAN com-
munication line.
OPERATING PRINCIPLE
System Time Table
JSEIA0220GB
Component parts Control signal
ECM Transmits the following signal via CAN communication line to air levelizer control module.
 Engine speed signal
Combination meter Receives the following signal via CAN communication line from air levelizer control module.
 CK SUSP indicato
r lamp signal
ABS actuator and elec tric unit (con-
trol unit) Transmits the following signal via CAN communication line to air levelizer control module.
 Vehicle speed signal
Revision: 2010 May2011 QX56

SYSTEMSCS-55
< SYSTEM DESCRIPTION > [AIR LEVELIZER CONTROL SYSTEM]
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Vehicle height raises [When starting engi
ne, if vehicle height of vehicle rear continues for 30 seconds or more in a
status that is 15 mm (0.59 in) or less than standard vehicle height]
1. Vehicle height sensor detects vehicle height status, and transmits this information to air levelizer control
module.
2. Air levelizer control module turns air compressor relay ON and operates air compressor.
3. Air compressor charges air in air chamber of shock absorber.
4. Vehicle height raises, and control is complete when status is −1 mm ( −0.04 in) of standard vehicle height
value.
Vehicle height lowers [When starting engine, if vehicle height of vehicle rear continues for 30 seconds or more in a
status that is 15 mm (0.59 in) or more of standard vehicle height]
1. Vehicle height sensor detects vehicle height status, and transmits this information to air levelizer control
module.
2. Air levelizer control module turns exhaust solenoid of air compressor ON.
3. Air compressor discharges air from air chamber of shock absorber.
4. Vehicle height lowers, and control is complete when st atus is +1 mm (+0.04 in) of standard vehicle height.
Fail-safeINFOID:0000000006256051
If malfunction is detected, control stops.
The system may enter fail-safe mode under certain conditions (for example, over-laden conditions) when elec-
tronic circuit is normal.
In this case, always check that the system re turns to normal by starting engine after unloading load.
JSEIA0221GB
Revision: 2010 May2011 QX56

SCS-56
< SYSTEM DESCRIPTION >[AIR LEVELIZER CONTROL SYSTEM]
DIAGNOSIS SYSTEM (AIR
LEVELIZER CONTROL MODULE)
DIAGNOSIS SYSTEM (AIR LE VELIZER CONTROL MODULE)
CONSULT-III FunctionINFOID:0000000006256052
CONSULT-III APPLICATION ITEMS
WORK SUPPORT
CAUTION:
Perform the procedure when the vehicle is stopped.
SELF DIAGNOSTIC RESULTS
Refer to SCS-59, "DTC Index".
When “CRNT” is displayed on self-diagnosis result,
 The system is presently malfunctioning.
When “PAST” is displayed on self-diagnosis result, System malfunction in the past is detect ed, but the system is presently normal.
Freeze frame data (FFD)
DATA MONITOR
Diagnostic test mode Function
Work Support This mode enables a technician to adjust some devices faster and more accurately.
Self Diagnostic Results Retrieve DTC from ECU and display diagnostic items.
Data Monitor Monitor the input/output signal of the control unit in real time.
CAN Diagnosis This mode displays a network diagnosis result about CAN by a diagram.
CAN Diagnostic Support
Monitor It monitors the status of CAN communication.
ECU Identification Display the ECU identification number (part number etc.) of the selected system.
Active Test Send the drive signal from CONSULT-III to the actuator. The operation check can be performed.
Item name Description
STANDARD HEIGHT LEVEL Forcibly sets vehicle height to the set standard vehicle height.
ADJUST HEIGHT INI Sets standard vehicle height.
CLEAR HEIGHT INI Erases standard vehicle height.
Item name Description
IGN COUNTER The number of times that ignition switch is turned ON after the DTC is detected is displayed.
 When “0” is displayed: It indicates that the system is presently malfunctioning.
 When except “0” is displayed: It indicates that system malfunction in the past is detected, but the system
is presently normal.
NOTE:
Each time when ignition switch is turned OFF to ON, numerical number increases in 1 → 2 → 3...38 → 39.
When the operation number of times exceeds 39, the number do not increase and “39” is displayed until
self-diagnosis is erased.
Monitored item (Unit) Remarks
IGN VOLT (V) Displays the power supply voltage of air levelizer control module.
VHCL HT INTLZ STA Displays setting status of standard vehicle height.
VHCL HT INIT SLCT Displays setting status of standard vehicle height.
VHCL HEIGHT SEN (V) Displays the signal voltage of vehicle height sensor.
VHCL HT CNVSN VL (mm) Displays the vehicle height recognized by air levelizer control module.
VHCL HGT FIX TIME (hour) Displays period of time that signal from vehicle height sensor does not change.
Revision: 2010 May2011 QX56

DIAGNOSIS AND REPAIR WORKFLOWSCS-65
< BASIC INSPECTION > [AIR LEVELIZER CONTROL SYSTEM]
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BASIC INSPECTION
DIAGNOSIS AND REPAIR WORKFLOW
Work FlowINFOID:0000000006256058
DETAILED FLOW
1.INTERVIEW FROM THE CUSTOMER
Clarify customer complaints before inspection. First of all, perform an interview utilizing SCS-66, "
Diagnostic
Work Sheet" and reproduce the symptom as well as fully under stand it. Ask customer about his/her complaints
carefully.Check symptoms by driving vehicle with customer, if necessary.
CAUTION:
Customers are not professional. Never guess easily like “maybe the customer means that...,” or “
maybe the customer mentions this symptom”.
>> GO TO 2.
2.CHECK SYMPTOM
Reproduce the symptom that is indicated by the cu stomer, based on the information from the customer
obtained by interview. Also check that the sympt om is not caused by fail-safe mode. Refer to SCS-59, "
Fail-
safe".
CAUTION:
When the symptom is caused by normal operation, fully inspect each portion and obtain the under-
standing of customer that the symptom is not caused by a malfunction.
>> GO TO 3.
3.PERFORM THE SELF-DIAGNOSIS
With CONSULT-III
Perform self-diagnosis for “E-SUS”.
Is any DTC detected?
YES >> Record or print self-diagnosis results. GO TO 4.
NO >> GO TO 6.
4.RECHECK THE SYMPTOM
With CONSULT-III
1. Erase self-diagnostic results for “E-SUS”.
2. Perform DTC confirmation procedures for the error-detected system.
NOTE:
If some DTCs are detected at the some time, determine the order for performing the diagnosis based on
SCS-59, "
DTC Inspection Priority Chart".
Is any DTC detected?
YES >> GO TO 5.
NO >> Check harness and connectors based on the in formation obtained by interview. Refer to GI-40,
"Intermittent Incident".
5.REPAIR OR REPLACE ERROR-DETECTED PART
 Repair or replace error-detected parts.
 Reconnect part or connector after repairing or replacing.
 When DTC is detected, erase self -diagnostic result for “E-SUS”.
>> GO TO 7.
6.IDENTIFY ERROR-DETE CTED SYSTEM BY SYMPTOM DIAGNOSIS
Estimate error-detected system based on symptom diagnosis and perform inspection.
Can the error-detected system be identified?
Revision: 2010 May2011 QX56

SE-18
< SYSTEM DESCRIPTION >
SYSTEM
Malfunction Malfunctioning condition
The temperature difference between the seatback ther-
mal electric unit and seat cushion thermal electric unit is
more than 30 °C  When it detects for 4 seconds that the temperature difference between
the seatback thermal electric unit and seat cushion thermal electric unit
is more than 30 °, it stops the output to the thermal electric unit, activates
the climate controlled seat blower motor at the maximum position, and
sends the external airflow for 30 seconds
 If the temperature difference is still more than 30 °C after 30 seconds
pass, it stops all output and enters the system OFF condition
 When the temperature difference between seatback thermal electric unit and seat cushion thermal electric unit becomes less than 20 °C, the sys-
tem recovers automatically
 If it detects that the temperature difference is more than 30 °C after the
automatic system recovery, it immediately stops all output and enters the
system OFF condition
NOTE:
When the switch operation is performed before entering the system OFF
condition, the fail-safe mode is reset.
The temperature of thermal electric unit is more than
11 0 °C in the HEAT mode (any thermal electric unit in the
seatback or seat cushion)  When it detects for 4 seconds that the temperature of the thermal electric
unit is more than 110 °C, it stops the output to the thermal electric unit,
activates the climate controlled seat blower motor at the maximum posi-
tion, and sends the external airflow for 30 seconds
 If the temperature does not become less than 105 °C after 30 seconds
pass, it stops all output and enters the system OFF condition
 When the temperature of the thermal electric unit becomes less than 105 °C, the system recovers automatically
 If it detects that the temperature of the thermal electric unit is more than
11 0 °C after the automatic system recovery, it immediately stops all out-
put and enters the system OFF condition
The temperature of the thermal electric unit is more than
45 °C in the COOL mode (any thermal electric unit in the
seatback or seat cushion)  When it detects for 4 seconds that the temperature of the thermal electric
unit is more than 45 °C and less than 70 °C, it starts the temperature mon-
itoring of the thermal electric unit at 3 second intervals
 While monitoring, if it detects that the temperature continuously rises 2 °C
or more 4 times or reaches 70 °C or more, it stops all output and enters
the system OFF condition
 If it detects other results of monitoring, it continues activating in the COOL mode
Thermal electric unit sensor open circuit
(in either the back and the cushion TEU)  When it detects for 4 seconds that the thermal electric unit sensor is an
open circuit, it stops all output and enters the system OFF condition
Climate controlled seat blower motor system open circuit
(in either the back and the cushion blower)  When it detects for 2 seconds that climate controlled seat blower motor
is an open circuit while the climate controlled seat is being activated, and
the battery status has been stable for the same 2 second period. it stops
output to the thermal electric unit
 When it detects for 10 seconds that the climate controlled seat blower motor is an open circuit while the climate controlled seat is being activat-
ed, and the battery status has been stable for the same 10second period.
it stops all output and enters the system OFF condition
NOTE:
After detecting the climate seat blower motor system open circuit for 2
seconds, the system recovers automatically if the activation of the cli-
mate controlled seat blower motor is detected for 1 second or more.
Switch input out of the specified range
(either heat input or cool input)  When it detects for 4 seconds that the rotary switch input is less than
30% of the vehicle battery voltage, it stops all output and enters the sys-
tem OFF condition
 When the switch input returns to a value within the specified range, the system recovers automatically
Revision: 2010 May2011 QX56

SYSTEMSE-19
< SYSTEM DESCRIPTION >
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*: System voltage is the voltage between the climate controlled seat control unit power source and ground.
NOTE:
When the ignition status changes to OFF during the fail-safe mode, the control unit shall enter the OFF condition. If the ignit ion is turned
ON, the system shall return to the standby mode. If the system en ters in the fail-safe mode again after performing ignition cycle, start the
diagnosis. HEAT or COOL switch input out of the specified range
 During the standby mode, heating or cooling states, if the rotary switch
input is 6% or less of the vehicle battery voltage, it stops all output and
enters the system OFF condition
 When the switch input returns to a value within the specified range, the system recovers automatically
System voltage out of range  If the system voltage at the climate controlled seat control unit falls out-
side of the 8.5 to 16.5 V operating range, it stops all output after a 500ms
time period.
 When the system voltage returns to the normal operating range (10.5-
15.5V with a 500ms hysteresis), the system recovers automatically.
Malfunction Malfunctioning condition
Revision: 2010 May2011 QX56