2004 INFINITI QX56 Can communication

GW-96
REAR WINDOW DEFOGGER
Revision: August 20072004 QX56
3. CHECK DOOR MIRROR DEFOGGER
Check continuity between door mirror RH terminals 10 and 11.
OK or NG
OK >> Repair or replace harness.
NG >> Replace door mirror RH.
Rear Window Defogger Signal CheckEIS002W6
1. CHECK AV COMMUNICATION LINE
AV communication line check is executed. Refer to AT C - 3 2 , "
CAN Communication System Description" .
OK or NG
OK >> GO TO 2.
NG >> Replace display control unit.
2. CHECK CAN COMMUNICATION LINE
CAN communication line check is executed. Refer to LAN-5, "
CAN COMMUNICATION" .
OK or NG
OK >> Check the condition of the harness and the connector.
NG >> In addition, it is necessary to check CAN communication line. Refer to LAN-5, "
CAN COMMUNI-
CATION" .
Filament CheckEIS002W7
1. When measuring voltage, wrap tin foil around the top of the neg-
ative probe.Then press the foil against the wire with your finger.
2. Attach probe circuit tester (in Volt range) to middle portion of
each filament.10 - 11 : Continuity should exist.
LIIA2305E
Is rear window defogger displayed on the display?
SEL122R
SEL263

IDX-2
ALPHABETICAL INDEX
Numerics
2-4WD shift solenoid valve ................................ TF-95
4LO indicator lamp ............................................. TF-90
4WD shift indicator lamp .................................... TF-85
4WD shift switch ................................................ TF-95
4WD solenoid valve ........................................... TF-95
4WD warning lamp ............................................ TF-13
A
A/C air flow ...................................................... ATC-29
A/C compressor clutch removal and installation .. ATC-
167
A/C compressor mounting ............................. ATC-166
A/C compressor precaution ............................. ATC-11
A/C compressor special service tool ................ ATC-14
A/C control operation (auto A/C) ...................... ATC-26
A/C diagnostic work flow (auto A/C) .............. ATC-120
A/C evaporator ............................................... ATC-175
A/C HFC134a (R134a) system identification ..... ATC-7
A/C HFC134a (R134a) system precaution ........ ATC-5
A/C HFC134a (R134a) system service procedure ATC-
162
A/C HFC134a (R134a) system service tools ... ATC-14
A/C HFC134a system service equipment precaution ...
ATC-11
A/C lubricant (R134a) ...................................... ATC-22
A/C lubrication oil ............................................. ATC-22
A/C operational check ....................... ATC-56, ATC-59
A/C self-diagnoses (auto A/C) ........ ATC-53, ATC-120
A/C service data specification ........................ ATC-182
A/C trouble diagnoses (auto A/C) .................... ATC-33
A/C, A - Wiring diagram ................................... ATC-41
A/T - Wiring diagram .......................................... AT-52
A/T fluid checking ...................... AT-13, AT-58, MA-21
A/T fluid cooler cleaning .................................... AT-15
A/T fluid replacement ............................. AT-13, MA-23
A/T fluid temperature sensor ........................... AT-131
A/T IND - Wiring diagram .................................... DI-41
A/T indicator ........................................................ DI-41
A/T shift lock system ........................................ AT-236
A/T trouble diagnoses ........................................ AT-43
ABS - Wiring diagram ..................................... BRC-16
ABS (anti-lock brake system) ........................... BRC-7
Accelerator control system ............................... ACC-2
Accelerator pedal position (APP) sensor . EC-556, EC-
562, EC-576
Accelerator pedal released position learning ..... EC-44
AF1B1-Wiring diagram EC-431, EC-439, EC-447, EC-
456, EC-466, EC-475, EC-487
AF1B2-Wiring diagram EC-433, EC-441, EC-449, EC-
458, EC-468, EC-477, EC-489
AF1HB1-Wiring diagram .................................. EC-355
AF1HB2-Wiring diagram .................................. EC-357
Aiming adjustment .................................. LT-31, LT-78
Air bag .............................................................. SRS-3
Air cleaner and air duct ..................................... EM-14
Air cleaner filter replacement ............................ MA-15
Air conditioner cut control ................................. EC-30
Air flow meter - See Mass air flow sensor EC-146, EC-
154
Air fuel ratio sensor 1 .. EC-429, EC-437, EC-445, EC-
454, EC-463, EC-472, EC-484
Air fuel ratio sensor 1 heater ........................... EC-354
Air mix. door motor .......................................... ATC-67
All - mode 4WD system ..................................... TF-10
Ambient sensor ............................. ATC-125, ATC-136
Angular tightening application ............................. EM-3
APPS1 - Wiring diagram ................................. EC-558
APPS2 - Wiring diagram ................................. EC-564
APPS3 - Wiring diagram ................................. EC-578
ASC/BS - Wiring diagram ............................... EC-536
ASC/SW - Wiring diagram .............................. EC-519
ASCBOF - Wiring diagram .............................. EC-622
ASCD .............................................................. EC-647
ASCD (automatic speed control device) ........... ACS-3
ASCD brake switch ........................... EC-534, EC-621
ASCD indicator lamp ....................................... EC-628
ASCD steering switch ..................................... EC-517
ASCIND - Wiring diagram ............................... EC-629
ATP switch ......................................................... TF-96
ATP warning lamp .............................................. TF-89
AUDIO - Wiring diagram .................................... AV-10
AUT/DP - Wiring diagram .................................. SE-19
Auto air conditioner - Wiring diagram .............. ATC-41
Auto anti-dazzling inside mirror ........... GW-76, GW-77
Autolamp ............................................................ LT-47
Automatic amplifier ......................................... ATC-60
Automatic transmission number .......................... GI-48
AV and NAVI control unit ................................... AV-63
AV communication line ...................................... AV-87
B
Back door trim ..................................................... EI-31
Back sonar .......................................................... DI-59
BACK/L - Wiring diagram ................................. LT-106
Back-up lamp ................................................... LT-106
Ball joint (front) ................................................ FSU-15
Basic inspection ................................................ EC-79
Battery ................................................................. SC-4
Battery/Starting/Charging System Tester SC-6, SC-12,
SC-19
BCM (Body control module) .............................. BCS-3
Block heater ...................................................... EM-73
Blower motor ................................... ATC-83, ATC-140
Body alignment ................................................ BL-174
Body component parts ..................................... BL-161
Body construction ............................................ BL-173
Body exterior paint color .................................. BL-160
Body mounting ................................................. BL-159
Body repair ....................................................... BL-160
Body sealing .................................................... BL-170
Brake booster .................................................... BR-17
Brake fluid level ................................................. MA-27
Brake hydraulic line ........................................... BR-12
Brake inspection ............................................... MA-28

IDX-3
A
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IDX
ALPHABETICAL INDEX
Brake lines and cables inspection ..................... MA-27
Brake master cylinder ....................................... BR-15
Brake switch .................................................... EC-551
BRK/SW - Wiring diagram ............................... EC-552
Bulb specifications ........................................... LT-170
Bumper, front ...................................................... EI-13
Bumper, rear ....................................................... EI-15
C
Cabin air filter .................................................... MA-20
Camshaft ........................................................... EM-43
Camshaft inspection .......................................... EM-47
Camshaft position sensor (PHASE) ................ EC-261
CAN - Wiring diagram EC-136, LAN-18, LAN-52, LAN-
92, LAN-128
CAN (Controller Area Network) .. WT-9, BRC-10, LAN-
16, LAN-50, LAN-90, LAN-126
CAN communication . EC-31, EC-135, AT-103, WT-9,
BRC-10
, LAN-16, LAN-50, LAN-90, LAN-126
Canister-See EVAP canister ........................... EC-636
Center case (Transfer) ..................................... TF-113
CHARGE - Wiring diagram ............................... SC-18
Charging system ............................................... SC-17
Chassis and body maintenance ........................ MA-20
Chassis and body maintenanceSchedule 1 ........ MA-7
Chassis and body maintenanceSchedule 2 ........ MA-9
CHIME - Wiring diagram ..................................... DI-46
Circuit breaker ................................................... PG-67
Clock ................................................................... DI-70
CLOCK - Wiring diagram .................................... DI-70
Closed loop control ........................................... EC-27
Closed loop control (Bank 1) ........................... EC-407
Closed loop control (Bank 2) ........................... EC-407
Clutch drum (Transfer) ..................................... TF-116
Clutch force release limit adjustment ................. TF-42
Clutch pressure switch (Transfer) ...................... TF-95
Coil spring (front) ............................................. FSU-10
Collision diagnosis .......................................... SRS-60
Combination lamp, front, removal and installation . LT-
33
Combination lamp, rear, removal and installation .. LT-
122
Combination meter ................................................ DI-5
Combination switch ............................................ LT-97
COMBSW - Wiring diagram ............................... LT-97
COMM - Wiring diagram ................................... AV-87
COMPAS - Wiring diagram ................................. DI-27
Compass ............................................................. DI-26
Component Location (auto A/C) ...................... ATC-37
Compressor clutch removal and installation . ATC-167
Compressor mounting ................................... ATC-166
Compressor precaution ................................... ATC-11
Compressor special service tool ..................... ATC-14
Condenser ..................................................... ATC-173
Connecting rod .................................................. EM-91
Connecting rod bearing clearance .................... EM-91
Connecting rod bushing clearance .................... EM-91
Console box - See Instrument panel ................... IP-10
Console box lamp ............................................. LT-152
CONSULT for all-mode 4WD ............................. TF-31
CONSULT for VDC ......................................... BRC-28
CONSULT-II for engine ................................... EC-103
Control units (terminal arrangement) ................. PG-71
Control valve (A/T) ............................................. AT-37
Control valve (Transfer) .................................... TF-119
Controller Area Network (CAN) . WT-9, BRC-10, LAN-
16, LAN-50, LAN-90, LAN-126
Converter housing installation ............ AT-257, AT-260
COOL/F - Wiring diagram ................................ EC-413
Coolant mixture ratio ......................................... MA-11
Coolant replacement ......................................... MA-12
Cooling circuit (engine) ........................................ CO-6
Cooling fan ........................................................ CO-13
Cooling fan control ........................................... EC-410
Cooling fan motor ............................................ EC-419
Cooling unit (A/C evaporator) ....... ATC-144, ATC-175
Corrosion protection ......................................... BL-167
Crankcase ventilation system - See Positive crankcase
ventilation ........................................................ EC-645
Crankshaft ......................................................... EM-74
Crankshaft position sensor (POS) ................... EC-255
Crash zone sensor .......................................... SRS-55
Cylinder block .................................................... EM-73
Cylinder block boring ......................................... EM-94
D
D/LOCK - Wiring diagram ................................... BL-20
Data link connector .......................................... EC-105
Daytime light system .......................................... LT-34
Daytime running light - See Daytime light system .. LT-
34
DEF - Wiring diagram ....................................... GW-82
Diagnosis sensor unit ...................................... SRS-58
Diagnostic trouble code (DTC) .......................... EC-53
Diagnostic trouble code (DTC) for OBD system .. EC-8
Diagnostic trouble code (DTC) inspection priority chart
EC-76
Differential carrier assembly ............................ RFD-11
Differential carrier disassembly ....................... RFD-13
Differential gear oil replacement ........................ MA-25
Dimensions ......................................................... GI-49
Direct clutch solenoid valve ................ AT-157, AT-160
Display and amp.assembly .............................. ATC-60
Display Control Unit ......................................... AV-158
Dome light - See Interior lamp .......................... LT-129
Door glass .......................................... GW-69, GW-72
Door lock .......................................................... BL-132
Door mirror lamp ............................................... LT-129
Door trim .............................................................. EI-31
Door, front ........................................... BL-129, GW-69
Door, rear ........................................... BL-129, GW-72
Drive belt ........................................................... EM-12
Drive chain (Transfer) ....................................... TF-115
Drive pinion diff. inspection .............................. RFD-12
Drive pinion height ........................................... RFD-17
Drive shaft (rear) ................................................ RAX-7

LAN-1
LAN SYSTEM
K ELECTRICAL
CONTENTS
C
D
E
F
G
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L
M
SECTION LAN
A
B
LAN
Revision: August 20072004 QX56
CAN
PRECAUTIONS .......................................................... 3
Precautions for Supplemental Restraint System
(SRS) “AIR BAG” and “SEAT BELT PRE-TEN-
SIONER” .................................................................. 3
Precautions When Using CONSULT-II ..................... 3
CHECK POINTS FOR USING CONSULT-II ......... 3
Precautions For Trouble Diagnosis .......................... 3
CAN SYSTEM ....................................................... 3
Precautions For Harness Repair .............................. 4
CAN SYSTEM ....................................................... 4
CAN COMMUNICATION ............................................ 5
System Description .................................................. 5
CAN Communication Unit ........................................ 5
TYPE1 ................................................................... 5
TYPE2 ................................................................... 8
TYPE 3 ................................................................ 10
TYPE 4 ................................................................ 13
CAN SYSTEM (TYPE 1) ........................................... 16
System Description ................................................ 16
Component Parts and Harness Connector Location ... 16
Schematic .............................................................. 17
Wiring Diagram - CAN - ......................................... 18
Work Flow .............................................................. 21
CHECK SHEET ................................................... 23
CHECK SHEET RESULTS (EXAMPLE) ............. 25
Circuit Check Between TCM and Driver Seat Con-
trol Unit ................................................................... 40
Circuit Check Between Driver Seat Control Unit and
Data Link Connector .............................................. 41
Circuit Check Between Data Link Connector and
IPDM E/R ............................................................... 42
ECM Circuit Check ................................................. 43
TCM Circuit Check ................................................. 43
Driver Seat Control Unit Circuit Check ................... 44
Combination Meter Circuit Check .......................... 44
Display Control Unit Circuit Check ......................... 45
BCM Circuit Check ................................................. 45
Data Link Connector Circuit Check ........................ 46
Steering Angle Sensor Circuit Check ..................... 46Front Air Control Circuit Check ............................... 47
ABS Actuator and Electric Unit (Control Unit) Circuit
Check ..................................................................... 47
IPDM E/R Circuit Check ......................................... 48
CAN Communication Circuit Check ........................ 48
IPDM E/R Ignition Relay Circuit Check .................. 49
Component Inspection ............................................ 49
ECM/IPDM E/R INTERNAL CIRCUIT INSPEC-
TION .................................................................... 49
CAN SYSTEM (TYPE 2) ........................................... 50
System Description ................................................. 50
Component Parts and Harness Connector Location ... 50
Schematic ............................................................... 51
Wiring Diagram - CAN - .......................................... 52
Work Flow ............................................................... 55
CHECK SHEET ................................................... 57
CHECK SHEET RESULTS (EXAMPLE) ............. 59
Circuit Check Between TCM and ICC Sensor ........ 78
Circuit Check Between ICC Sensor and ICC Unit ... 79
Circuit Check Between ICC Unit and Driver Seat
Control Unit ............................................................. 80
Circuit Check Between Driver Seat Control Unit and
Data Link Connector ............................................... 80
Circuit Check Between Data Link Connector and
IPDM E/R ................................................................ 81
ECM Circuit Check ................................................. 82
TCM Circuit Check ................................................. 82
ICC Sensor Circuit Check ....................................... 83
ICC Unit Circuit Check ............................................ 83
Driver Seat Control Unit Circuit Check ................... 84
Combination Meter Circuit Check ........................... 84
Display Control Unit Circuit Check ......................... 85
BCM Circuit Check ................................................. 85
Data Link Connector Circuit Check ........................ 86
Steering Angle Sensor Circuit Check ..................... 86
Front Air Control Circuit Check ............................... 87
ABS Actuator and Electric Unit (Control Unit) Circuit
Check ..................................................................... 87
IPDM E/R Circuit Check ......................................... 88
CAN Communication Circuit Check ........................ 88

LAN-2Revision: August 20072004 QX56 IPDM E/R Ignition Relay Circuit Check ................... 89
Component Inspection ............................................ 89
ECM/IPDM E/R INTERNAL CIRCUIT INSPEC-
TION .................................................................... 89
CAN SYSTEM (TYPE 3) ........................................... 90
System Description ................................................. 90
Component Parts and Harness Connector Location ... 90
Schematic ............................................................... 91
Wiring Diagram - CAN - .......................................... 92
Work Flow ............................................................... 95
CHECK SHEET ................................................... 97
CHECK SHEET RESULTS (EXAMPLE) ............. 99
Circuit Check Between TCM and Driver Seat Con-
trol Unit .................................................................115
Circuit Check Between Driver Seat Control Unit and
Data Link Connector .............................................116
Circuit Check Between Data Link Connector and
IPDM E/R ..............................................................117
ECM Circuit Check ...............................................118
TCM Circuit Check ...............................................118
Driver Seat Control Unit Circuit Check .................119
Combination Meter Circuit Check .........................119
Display Control Unit Circuit Check ........................120
BCM Circuit Check ...............................................120
Data Link Connector Circuit Check .......................121
Steering Angle Sensor Circuit Check ...................121
Front Air Control Circuit Check .............................122
Transfer Control Unit Circuit Check ......................122
ABS Actuator and Electric Unit (Control Unit) Circuit
Check ...................................................................123
IPDM E/R Circuit Check .......................................123
CAN Communication Circuit Check ......................124
IPDM E/R Ignition Relay Circuit Check .................124
Component Inspection ..........................................125
ECM/IPDM E/R INTERNAL CIRCUIT INSPEC-
TION ..................................................................125CAN SYSTEM (TYPE 4) .......................................... 126
System Description ............................................... 126
Component Parts and Harness Connector Location . 126
Schematic ............................................................. 127
Wiring Diagram - CAN - ........................................ 128
Work Flow ............................................................. 131
CHECK SHEET ................................................. 133
CHECK SHEET RESULTS (EXAMPLE) ............ 135
Circuit Check Between TCM and ICC Sensor ...... 155
Circuit Check Between ICC Sensor and ICC Unit . 156
Circuit Check Between ICC Unit and Driver Seat
Control Unit ........................................................... 157
Circuit Check Between Driver Seat Control Unit and
Data Link Connector ............................................. 157
Circuit Check Between Data Link Connector and
IPDM E/R .............................................................. 158
ECM Circuit Check ................................................ 159
TCM Circuit Check ................................................ 159
ICC Sensor Circuit Check ..................................... 160
ICC Unit Circuit Check .......................................... 160
Driver Seat Control Unit Circuit Check .................. 161
Combination Meter Circuit Check ......................... 161
Display Control Unit Circuit Check ........................ 162
BCM Circuit Check ................................................ 162
Data Link Connector Circuit Check ....................... 163
Steering Angle Sensor Circuit Check .................... 163
Front Air Control Circuit Check ............................. 164
Transfer Control Unit Circuit Check ...................... 164
ABS Actuator and Electric Unit (Control Unit) Circuit
Check .................................................................... 165
IPDM E/R Circuit Check ........................................ 165
CAN Communication Circuit Check ...................... 166
IPDM E/R Ignition Relay Circuit Check ................. 166
Component Inspection .......................................... 167
ECM/IPDM E/R INTERNAL CIRCUIT INSPEC-
TION .................................................................. 167

PRECAUTIONS
LAN-3
[CAN]
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MA
B
LAN
Revision: August 20072004 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
UKS0017I
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity 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 whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WA RN ING:

To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions When Using CONSULT-IIUKS0017J
When connecting CONSULT-II to data link connector, connect them through CONSULT-II CONVERTER.
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 carry out CAN communication.
CHECK POINTS FOR USING CONSULT-II
1. Has CONSULT-II been used without connecting CONSULT-II CONVERTER on this vehicle?
–If YES, GO TO 2.
–If NO, GO TO 5.
2. Is there any indication other than indications relating to CAN communication system in the self-diagnosis
results?
–If YES, GO TO 3.
–If NO, GO TO 4.
3. Based on self-diagnosis results unrelated to CAN communication, carry out the inspection.
4. Malfunctions may be detected in self-diagnosis depending on control units carrying out CAN communica-
tion. Therefore, erase the self-diagnosis results.
5. Diagnose CAN communication system. Refer to LAN-5, "
CAN Communication Unit" .
Precautions For Trouble DiagnosisUKS0017K
CAN SYSTEM

Do not apply voltage of 7.0V or higher to the measurement terminals.

Use the tester with its open terminal voltage being 7.0V or less.

Be sure to turn ignition switch off and disconnect negative battery terminal before checking the circuit.

CAN COMMUNICATION
LAN-5
[CAN]
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LAN
Revision: August 20072004 QX56
CAN COMMUNICATIONPFP:23710
System DescriptionUKS000NU
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
CAN Communication UnitUKS000NV
Go to CAN system, when selecting your CAN system type from the following table.
×: Applicable
TYPE1
System diagram

Ty p e 1
Input/output signal chart
T: Transmit R: Receive Body typeWagon
Axle 2WD 4WD
EngineVK56DE
TransmissionA/T
Brake controlVDC
ICC system××
CAN system type 1234
CAN system trouble diagnosisLAN-16
LAN-50LAN-90LAN-126
PKIA8173E
Signals ECM TCMDriver
seat
con-
trol
unitCom-
bina-
tion
meterDis-
play
con-
trol
unitBCMStee r-
ing
angle
sensorFront
air
control ABS
actua-
tor and
elec-
tric unit
(con-
trol
unit)IPDM
E/R
Engine speed signal T R R R R
Engine status signal T R R

LAN-6
[CAN]
CAN COMMUNICATION
Revision: August 20072004 QX56
Engine coolant temperature signal T R R R
A/T self-diagnosis signal R T
Accelerator pedal position signal T R R
Closed throttle position signal T R
Wide open throttle position signal T R
Battery voltage signal T R
Key switch signal R T
Ignition switch signal R T R
P range signal T R
Stop lamp switch signal R T R
Parking brake switch signal T R
Fuel consumption monitor signalTR
TR
Turbine revolution signal R T
Output shaft revolution signal R T
A/C switch signal R T
A/C compressor request signal T R R
Blower fan motor switch signal R T R
A/C switch/indicator signalTR
RT
Cooling fan speed request signal T R R
Position light request signal R T R
Low beam request signal T R
Low beam status signal RT
High beam request signal R T R
High beam status signal RT
Front fog light request signal T R
Day time running light request signal T R
Vehicle speed signalRRT
RRRTRR R
Sleep wake up signal R T R
Door switch signal R R R T R
Turn indicator signal R T
Key fob ID signal R T
Key fob door unlock signal R T
Buzzer output signal R T
Fuel level sensor signal R T
Fuel level low warning signal T R
ASCD SET lamp signal T R
ASCD CRUISE lamp signal T RSignals ECM TCMDriver
seat
con-
trol
unitCom-
bina-
tion
meterDis-
play
con-
trol
unitBCMStee r-
ing
angle
sensorFront
air
control ABS
actua-
tor and
elec-
tric unit
(con-
trol
unit)IPDM
E/R