2011 INFINITI QX56 ignition

LAN
TROUBLE DIAGNOSISLAN-11
< SYSTEM DESCRIPTION > [CAN FUNDAMENTAL]
C
D
E
F
G H
I
J
K L
B A
O P
N
TROUBLE DIAGNOSIS
Condition of Error DetectionINFOID:0000000006220517
DTC of CAN communication is indicated on SELF-DIA
G RESULTS on CONSULT-III if a CAN communication
signal is not transmitted or received between units for 2 seconds or more.
NOTE:
DTCs of CAN communication are as follows:
 U0101
 U0140
 U0164
 U1000
 U1001
 U1507
 U1508
CAN COMMUNICATION SYSTEM ERROR
 CAN communication line open (CAN-H, CAN-L, or both)
 CAN communication line short (ground, betw een CAN communication lines, other harnesses)
 Error of CAN communication control circuit of the unit connected to CAN communication line
WHEN DTC OF CAN COMMUNICATION IS I NDICATED EVEN THOUGH CAN COMMUNICATION
SYSTEM IS NORMAL
 Removal/installation of parts: Error may be detec ted when removing and installing CAN communication unit
and related parts while turning the ignition switch ON. (A DTC except for CAN communication may be
detected.)
 Fuse blown out (removed): CAN communication of the unit may cease.
 Voltage drop: Error may be detected if voltage drops due to discharged battery when turning the ignition
switch ON (Depending on the control unit which carries out CAN communication).
 Error may be detected if the power supply circuit of the control unit, which carries out CAN communication,
malfunctions (Depending on the control unit which carries out CAN communication).
 Error may be detected if reprogramming is not completed normally.
CAUTION:
CAN communication system is normal if DTC of CAN communication is indicated on SELF-DIAG
RESULTS of CONSULT-III under th e above conditions. Erase the memo ry of the self-diagnosis of each
unit.
Symptom When Error Occurs in CAN Communication SystemINFOID:0000000006220518
In CAN communication system, multiple units mutually transmit and receive signals. Each unit cannot transmit
and receive signals if any error occurs on CAN communicati on line. Under this condition, multiple control units
related to the root cause malfunction or go into fail-safe mode.
ERROR EXAMPLE
NOTE:
 Each vehicle differs in symptom of each unit under fail-safe mode and CAN communication line wiring.
 Refer to LAN-23, "
Abbreviation List" for the unit abbreviation.
Revision: 2010 May2011 QX56

LAN
TROUBLE DIAGNOSISLAN-13
< SYSTEM DESCRIPTION > [CAN FUNDAMENTAL]
C
D
E
F
G H
I
J
K L
B A
O P
N
NOTE:
 When data link connector branch line is open, transmi
ssion and reception of CAN communication signals
are not affected. Therefore, no symptoms occur. However, be sure to repair malfunctioning circuit.
 The model (all units on CAN communication system are Diag on CAN) cannot perform CAN diagnosis with
CONSULT-III if the following error occurs. The error is judged by the symptom.
Example: Main Line Between Data Link Connector and ABS Actuator and Electr ic Unit (Control Unit) Open Circuit
Unit name Major symptom
ECM
Normal operation.
BCM
EPS control unit
Combination meter
ABS actuator and electric
unit (control unit)
TCM
IPDM E/R
Error Difference of symptom
Data link connector branch line open circuit Normal operation.
CAN-H, CAN-L harness short-circuit Most of the units which are connected to the CAN communication
system enter fail-safe mode or are deactivated.
SKIB8740E
Unit name Major symptom
ECM Engine torque limiting is affected, and shift harshness increases.
BCM  Reverse warning chime does not sound.
 The front wiper moves under continuous operation mode even though the front wip-
er switch being in the intermittent position.
EPS control unit The steering effort increases.
Combination meter  The shift position indicator and OD OFF indicator turn OFF.
 The speedometer is inoperative.
 The odo/trip meter stops.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/R When the ignition switch is ON,
 The headlamps (Lo) turn ON.
 The cooling fan continues to rotate.
Revision: 2010 May2011 QX56

LAN-14
< SYSTEM DESCRIPTION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
Example: CAN-H, CAN-L Harness Short Circuit
CAN Diagnosis with CONSULT-IIIINFOID:0000000006220519
CAN diagnosis on CONSULT-III extracts the root
cause by receiving the following information.
 Response to the system call
 Control unit diagnosis information
 Self-diagnosis
 CAN diagnostic support monitor
SKIB8741E
Unit name Major symptom
ECM  Engine torque limiting is affected, and shift harshness increases.
 Engine speed drops.
BCM  Reverse warning chime does not sound.
 The front wiper moves under continuous operation mode even though the front
wiper switch being in the intermittent position.
 The room lamp does not turn ON.
 The engine does not start (if an error or malfunction occurs while turning the igni- tion switch OFF.)
 The steering lock does not release (if an error or malfunction occurs while turning the ignition switch OFF.)
EPS control unit The steeri ng effort increases.
Combination meter  The tachometer and the speedometer do not move.
 Warning lamps turn ON.
 Indicator lamps do not turn ON.
ABS actuator and electric unit (control unit) Normal operation.
TCM No impact on operation.
IPDM E/R When the ignition switch is ON,
 The headlamps (Lo) turn ON.
 The cooling fan continues to rotate.
Revision: 2010 May2011 QX56

LAN-16
< SYSTEM DESCRIPTION >[CAN FUNDAMENTAL]
TROUBLE DIAGNOSIS
With PAST
MONITOR ITEM (ON-BOARD DIAGNOSIS)
NOTE:
For some models, CAN communication diagnosis result is received from the vehicle monitor.
Example: Vehicle Display
Item PRSNT Description
Initial diagnosis OK Normal at present
NG Control unit error (Excep t for some control units)
Transmission diagnosis OK Normal at present
UNKWN Unable to transmit signals for 2 seconds or more.
Diagnosis not performed
Control unit name
(Reception diagnosis) OK Normal at present
UNKWN Unable to receive signals for 2 seconds or more.
Diagnosis not performed
No control unit for receiving signals. (No applicable optional parts)
Item PRSNT PAST Description
Transmission diagnosis OKOK Normal at present and in the past
1 – 39 Normal at present, but unable to transmit signals for 2 seconds or more
in the past. (The number indicates the number of ignition switch cycles
from OFF to ON.)
UNKWN 0 Unable to transmit signals for 2 seconds or more at present.
Control unit name
(Reception diagnosis) OK
OK Normal at present and in the past
1 – 39 Normal at present, but unable to receive signals for 2 seconds or more
in the past. (The number indicates the number of ignition switch cycles
from OFF to ON.)
UNKWN 0 Unable to receive signals for 2 seconds or more at present.
–– Diagnosis not performed.
No control unit for receiving signals. (No applicable optional parts)
Item
Result indi-
cated Error counter Description
CAN_COMM
(Initial diagnosis) OK 0 Normal at present
NG 1 – 50 Control unit error
(The number indicates how many times diagnosis has been
run.)
CAN_CIRC_1
(Transmission diagnosis) OK 0 Normal at present
UNKWN 1 – 50 Unable to transmit for 2 seconds or more at present.
(The number indicates how many times diagnosis has been
run.)
CAN_CIRC_2 – 9
(Reception diagnosis of each unit) OK 0 Normal at present
UNKWN 1 – 50 Unable to transmit for 2 seconds or more at present.
(The number indicates how many times diagnosis has been
run.)
Diagnosis not performed.
No control unit for receiving signals. (No applicable optional
parts)
Revision: 2010 May2011 QX56

LAN
DIAGNOSIS AND REPAIR WORKFLOWLAN-19
< BASIC INSPECTION > [CAN FUNDAMENTAL]
C
D
E
F
G H
I
J
K L
B A
O P
N
 Indication of the combination meter is important to det
ect the root cause because it is the most obvious to
the customer, and it performs CA N communication with many units.
INSPECTION OF VEHICLE CONDITION
Check whether the symptom is reproduced or not.
NOTE:
Do not turn the ignition switch OFF or disconnect the bat tery cable while reproducing the error. The error may
temporarily correct itself, making it difficult to determine the root cause.
CHECK OF CAN SYSTEM TYPE (HOW TO US E CAN SYSTEM TYPE SPECIFICATION CHART)
Determine CAN system type based on vehicle equipment.
NOTE:
 This chart is used if CONSULT-III does not automatically recognize CAN system type.
 There are two styles for CAN system type specificat ion charts. Depending on the number of available sys-
tem types, either style A or style B may be used.
CAN System Type Specification Chart (Style A)
NOTE:
SKIB8717E
Revision: 2010 May2011 QX56

LAN-24
< PRECAUTION >[CAN]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint S
ystem (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006238426
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
 To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision that would result in air bag inflation, all maintenance must be performed by
an authorized NISS AN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precautions for Trouble DiagnosisINFOID:0000000006220528
CAUTION:
 Never apply 7.0 V or more to the measurement terminal.
 Use a tester with open terminal voltage of 7.0 V or less.
 Turn the ignition switch OFF and disconnect th e battery cable from the negative terminal when
checking the harness.
Precautions for Harness RepairINFOID:0000000006220529
 Solder the repaired area and wrap tape around the soldered area.
NOTE:
A fray of twisted lines must be within 110 mm (4.33 in).
SKIB8766E
Revision: 2010 May2011 QX56

LAN-30
< SYSTEM DESCRIPTION >[CAN]
SYSTEM
P range signal T R R
R range signal T R R
Shift position signal R R T R R R R R
Tow mode indicator lamp
signalTR
Pre-roll over signal T R
Pre-tensioner operation
signal TR
AFS OFF indicator lamp
signal TR
A/C switch operation signal T R
Rear window defogger
switch signal TR
System selection signal T R
System setting signal TR R
RT
RT
Automatic back door re-
quest signal TR
Back door lock status signal T R
Buzzer output signal TR
RT
Buzzer request signal TR
RT
Dimmer signal T R R
Door switch signal T R R R R
Door unlock signal T R
Front fog light request sig-
nal TR
Front wiper request signal T R R
Handle position signal T R
Headlamp washer request
signal TR
High beam request signal T R R
Horn reminder signal T R
Ignition switch ON signal TRRR
RT
Ignition switch signal T R
Interlock/PNP switch signal TR
RT
Key ID signal T R
Key switch signal T R
Key warning lamp signal T R
Low beam request signal T R Signal name
ECM
4WD
ABS
TCM
A-BAG
AFSAV
BCM
CGW
HVAC
M&A
STRG
TPMS
IPDM-E ADP
PSB
E-SUS ICC
PWBD
Revision: 2010 May2011 QX56

LAN-32
< SYSTEM DESCRIPTION >[CAN]
SYSTEM
Steering calibration signal R T R
Hazard request signalRT
RT
Horn request signal R T
Low tire pressure warning
lamp signal RT
Tire pressure data signal R T
A/C compresso r feedback
signal RRT
Detention switch signal R T R
Engine restart control sig-
nal RT
Front wiper stop position
signal RT
High beam status signal R T
Hood switch signal R T
Low beam status signal R R T
Push-button ignition switch
status signal RT
Starter control relay signal R T
Steering lock unit status
signal RT
CK SUSP indi cator lamp
signal RT
Brake fluid pressure control
signal R
T
BSW warning lamp signal R T
IBA OFF indicator lamp sig-
nal RT
IBA operation signal RT
ICC operation signal R T
ICC warning lamp signal R T
Lane departure warning
lamp signal RT
LDP ON indicator lamp sig-
nal RT
Target yaw moment signal R T
Signal name
ECM
4WD
ABS
TCM
A-BAG
AFSAV
BCM
CGW
HVAC
M&A
STRG
TPMS
IPDM-E ADP
PSB
E-SUS ICC
PWBD
Revision: 2010 May2011 QX56