cooling INFINITI QX56 2004 Factory Service Manual

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
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Revision: August 20072004 QX56
IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
PFP:284B7
System DescriptionEKS007NN

IPDM E/R (Intelligent Power Distribution Module Engine Room) integrates the relay box and fuse block
which were originally placed in engine compartment. It controls integrated relays via IPDM E/R control cir-
cuits.

IPDM E/R-integrated control circuits perform ON-OFF operation of relays, CAN communication control,
etc.

It controls operation of each electrical component via ECM, BCM and CAN communication lines.
CAUTION:
None of the IPDM E/R integrated relays can be removed.
SYSTEMS CONTROLLED BY IPDM E/R
1. Lamp control
Using CAN communication lines, it receives signals from the BCM and controls the following lamps:

Headlamps (Hi, Lo)

Parking lamps

Tail lamps

Front fog lamps
2. Wiper control
Using CAN communication lines, it receives signals from the BCM and controls the front wipers.
3. Rear window defogger relay control
Using CAN communication lines, it receives signals from the BCM and controls the rear window defogger
relay.
4. A/C compressor control
Using CAN communication lines, it receives signals from the ECM and controls the A/C compressor
(magnetic clutch).
5. Starter control
Using CAN communication lines, it receives signals from the ECM and controls the starter relay.
6. Cooling fan control
Using CAN communication lines, it receives signals from the ECM and controls the cooling fan relays.
7. Horn control
Using CAN communication lines, it receives signals from the BCM and controls the horn relay.
CAN COMMUNICATION LINE CONTROL
With CAN communication, by connecting each control unit using two communication lines (CAN L-line, CAN
H-line), it is possible to transmit a maximum amount of information with minimum wiring. Each control unit can
transmit and receive data, and reads necessary information only.
1. Fail-safe control

When CAN communication with other control units is impossible, IPDM E/R performs fail-safe control.
After CAN communication returns to normal operation, it also returns to normal control.

Operation of control parts by IPDM E/R during fail-safe mode is as follows:
Controlled system Fail-safe mode
Headlamp

With the ignition switch ON, the headlamp (low) is ON.

With the ignition switch OFF, the headlamp (low) is OFF.
Tail and parking lamps

With the ignition switch ON, the tail and parking lamps are ON.

With the ignition switch OFF, the tail and parking lamps are OFF.
Cooling fan

With the ignition switch ON, the cooling fan HI operates.

With the ignition switch OFF, the cooling fan stops.
Front wiperUntil the ignition switch is turned off, the front wiper LO and HI remains in the same status it
was in just before fail−safe control was initiated.
Rear window defogger Rear window defogger relay OFF

PG-22
IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
Revision: August 20072004 QX56
All Signals, Main Signals, Selection From Menu
NOTE:
Perform monitoring of IPDM E/R data with the ignition switch ON. When the ignition switch is in ACC position,
display may not be correct.
ACTIVE TEST
Operation Procedure
1. Touch “ACTIVE TEST” on “SELECT DIAG-MODE” screen.
2. Touch item to be tested, and check operation.
3. Touch “START”.
4. Touch "STOP" while testing to stop the operation.
Item nameCONSULT-II
screen displayDisplay or unitMonitor item selection
Description
ALL
SIGNALSMAIN
SIGNALSSELECTION
FROM MENU
Motor fan requestMOTOR FAN
REQ1/2/3/4 X X X Signal status input from ECM
Compressor request AC COMP REQ ON/OFF X X X Signal status input from ECM
Position lights
requestTAIL & CLR REQ ON/OFF X X X Signal status input from BCM
Headlamp low beam
requestHL LO REQ ON/OFF X X X Signal status input from BCM
Headlamp high
beam requestHL HI REQ ON/OFF X X X Signal status input from BCM
Front fog lghts
requestFR FOG REQ ON/OFF X X X Signal status input from BCM
Front wiper request FR WIP REQSTOP/1LOW/
LOW/HIX X X Signal status input from BCM
Wiper auto stopWIP AUTO
STOPACT P/STOP P X X X Output status of IPDM E/R
Wiper protection WIP PROT OFF/Block X X X Control status of IPDM E/R
Starter request ST RLY REQ ON/OFF X X
Status of input signal
NOTE
Ignition relay
statusIGN RLY ON/OFF X X XIgnition relay status monitored
with IPDM E/R
Rear defogger
requestRR DEF REQ ON/OFF X X X Signal status input from BCM
Oil pressure switch OIL P SW OPEN/CLOSE X XSignal status input from IPDM
E/R (function is not enabled)
Hood switch HOOD SW OFF XSignal status input from IPDM
E/R (function is not enabled)
Theft warning horn
requestTHFT HRN REQ ON/OFF X X Signal status input from BCM
Horn chirp HORN CHIRP ON/OFF X X Output status of IPDM E/R
Daytime running
lamp requestDTRL REQ ON/OFF X X Signal status input from BCM
Test name CONSULT-II screen display Description
Rear defogger output REAR DEFOGGERWith a certain ON-OFF operation, the rear defogger relay can be oper-
ated.
Front wiper (HI, LO) output FRONT WIPERWith a certain operation (OFF, HI, LO), the front wiper relay (Lo, Hi)
can be operated.
Cooling fan output MOTOR FAN With a certain operation (1, 2, 3, 4), the cooling fan can be operated.
Lamp (HI, LO, TAIL, FOG)
outputEXTERNAL LAMPSWith a certain operation (OFF, TAIL, LO, HI, FOG), the lamp relay
(Low, High, Tail, Fog) can be operated.

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
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Revision: August 20072004 QX56
Auto Active TestEKS007NR
DESCRIPTION

In auto active test mode, operation inspection can be performed when IPDM E/R sends a drive signal to
the following systems:
–Rear window defogger
–Front wipers
–Tail and parking lamps
–Front fog lamps
–Headlamps (Hi, Lo)
–A/C compressor (magnet clutch)
–Cooling fan
OPERATION PROCEDURE
1. Close hood and front door RH, and lift wiper arms away from windshield (to prevent glass damage by
wiper operation).
NOTE:
When auto active test is performed with hood opened, sprinkle water on windshield beforehand.
2. Turn ignition switch OFF.
3. Turn ignition switch ON and, within 20 seconds, press front door switch LH 10 times. Then turn ignition
switch OFF.
4. Turn ignition switch ON within 10 seconds after ignition switch OFF.
5. When auto active test mode is actuated, horn chirps once.
6. After a series of operations is repeated three times, auto active test is completed.
NOTE:
When auto active test mode has to be cancelled halfway, turn ignition switch OFF.
CAUTION:
Be sure to perform BL-93, "
Door Switch Check" when the auto active test cannot be performed.
INSPECTION IN AUTO ACTIVE TEST MODE

When auto active test mode is actuated, the following seven steps are repeated three times.
Cornering lamp output CORNERING LAMP —
Horn output HORN With a certain ON-OFF operation, the horn relay can be operated.Test name CONSULT-II screen display Description
WKIA1972E

PG-24
IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
Revision: August 20072004 QX56
Concept of Auto Active Test

IPDM E/R actuates auto active test mode when it receives door switch signal from BCM via CAN commu-
nication line. Therefore, when auto active test mode is activated successfully, CAN communication
between IPDM E/R and BCM is normal.

If any of the systems controlled by IPDM E/R cannot be operated, possible cause can be easily diagnosed
using auto active test.
Diagnosis chart in auto active test mode
Symptom Inspection contents Possible cause
Rear window defogger
does not operate.Perform auto active
test. Does rear win-
dow defogger oper-
ate?YES

BCM signal input circuit
NO

Rear window defogger relay

Open circuit of rear window defogger

IPDM E/R malfunction

Harness or connector malfunction between IPDM E/R and rear window
defogger
Any of front wipers, tail
and parking lamps, front
fog lamps, and head-
lamps (Hi, Lo) do not
operate.Perform auto active
test. Does system in
question operate?YES

BCM signal input system
NO

Lamp/wiper motor malfunction

Lamp/wiper motor ground circuit malfunction

Harness/connector malfunction between IPDM E/R and system in
question

IPDM E/R (integrated relay) malfunction
A/C compressor does
not operate.Perform auto active
test. Does magnet
clutch operate?YES

BCM signal input circuit

CAN communication signal between BCM and ECM

CAN communication signal between ECM and IPDM E/R
NO

Magnet clutch malfunction

Harness/connector malfunction between IPDM E/R and magnet clutch

IPDM E/R (integrated relay) malfunction
Cooling fan does not
operate.Perform auto active
test. Does cooling fan
operate?YES

ECM signal input circuit

CAN communication signal between ECM and IPDM E/R
NO

Cooling fan motor malfunction

Harness/connector malfunction between IPDM E/R and cooling fan
motor

IPDM E/R (integrated relay) malfunction

HARNESS
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Revision: August 20072004 QX56
Wiring Diagram Codes (Cell Codes)EKS007NZ
Use the chart below to find out what each wiring diagram code stands for.
Refer to the wiring diagram code in the alphabetical index to find the location (page number) of each wiring
diagram.
Code Section Wiring Diagram Name
A/C,A ATC Auto Air Conditioner
A/SUSP RSU Rear Air Suspension
AF1B1 EC Air Fuel Ratio Sensor 1 (Bank 1)
AF1B2 EC Air Fuel Ratio Sensor 1 (Bank 2)
AF1HB1 EC Air Fuel Ratio Sensor 1 (Bank 1)
AF1HB2 EC Air Fuel Ratio Sensor 1 (Bank 2)
APPS1 EC Accelerator Pedal Position Sensor
APPS2 EC Accelerator Pedal Position Sensor
APPS3 EC Accelerator Pedal Position Sensor
ASC/BS EC ASCD Brake Switch
ASC/SW EC ASCD Steering Switch
ASCBOF EC ASCD Brake Switch
ASCIND EC ASCD Indicator
A/T AT A/T Assembly
AT/IND DI A/T Indicator Lamp
AUDIO AV Audio
AUTO/DP SE Automatic Drive Positioner
AUTO/L LT Auto Light Control
B/CLOS BL Back Door Auto Closure System
BACK/L LT Back-up Lamp
BRK/SW EC Brake Switch
CAN EC CAN Communication Line
CAN LAN CAN System
CHARGE SC Charging System
CHIME DI Warning Chime
CLOCK DI Clock
COMBSW LT Combination Switch
COMM AV Audio Visual Communication System
COMPAS DI Compass and Thermometer
COOL/F EC Cooling Fan Control
D/LOCK BL Power Door Lock
DEF GW Rear Window Defogger
DTRL LT Headlamp - With Daytime Light System
DVD AV DVD Entertainment System
ECM/PW EC ECM Power Supply for Back-Up
ECTS EC Engine Coolant Temperature Sensor
ETC1 EC Electric Throttle Control Function
ETC2 EC Throttle Control Motor Relay
ETC3 EC Throttle Control Motor
F/FOG LT Front Fog Lamp
F/PUMP EC Fuel Pump
FTTS EC Fuel Tank Temperature Sensor
FUELB1 EC Fuel Injection System Bank 1
FUELB2 EC Fuel Injection System Bank 2
H/AIM LT Headlamp Aiming Control
H/LAMP LT Headlamp
HORN WW Horn

PRECAUTIONS
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Revision: August 20072004 QX56
Service NoticeEDS0017L
1. Before proceeding with disassembly, thoroughly clean the outside of the all-mode 4WD transfer. It is
important to prevent the internal parts from becoming contaminated by dirt or other foreign matter.
2. Disassembly should be done in a clean work area.
3. Use lint-free cloth or towels for wiping parts clean. Common shop rags can leave fibers that could interfere
with the operation of the all-mode 4WD transfer.
4. Place disassembled parts in order for easier and proper assembly.
5. All parts should be carefully cleaned with a general purpose, non-flammable solvent before inspection or
reassembly.
6. Gaskets, seals and O-rings should be replaced any time the all-mode 4WD transfer is disassembled.
7. It is very important to perform functional tests whenever they are indicated.
8. The valve body contains precision parts and requires extreme care when parts are removed and serviced.
Place removed parts in a parts rack in order to replace them in correct positions and sequences. Care will
also prevent springs and small parts from becoming scattered or lost.
9. Properly installed valves, sleeves, plugs, etc. will slide along bores in valve body under their own weight.
10. Before assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings
and seals, and to hold bearings and washers in place during assembly. Do not use grease.
11. Extreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.
12. After overhaul, refill the transfer with new ATF.
13. When the all-mode 4WD transfer drain plug is removed, only some of the fluid is drained. Old all-mode
4WD transfer fluid will remain in torque converter and ATF cooling system. Always follow the proper pro-
cedure. Refer to MA-24, "
Changing Transfer Fluid" .
Wiring Diagrams and Trouble DiagnosisEDS001CE
When you read wiring diagrams, refer to the following:

GI-15, "How to Read Wiring Diagrams" .

PG-4, "POWER SUPPLY ROUTING CIRCUIT" for power distribution circuit.
When you perform trouble diagnosis, refer to the following:

GI-11, "HOW TO FOLLOW TEST GROUPS IN TROUBLE DIAGNOSES".

GI-27, "How to Perform Efficient Diagnosis for an Electrical Incident".