INFINITI QX4 2005 Factory Service Manual

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POWER SUPPLY ROUTING CIRCUIT
Revision: October 20052005 QX56
WKWA2628E

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
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IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
PFP:284B7
System DescriptionEKS00BN2

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

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IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
Revision: October 20052005 QX56
IPDM E/R STATUS CONTROL
In order to save power, IPDM E/R switches status automatically based on each operating condition.
1. CAN communication status

CAN communication is normally performed with other control units.

Individual unit control by IPDM E/R is normally performed.

When sleep request signal is received from BCM, mode is switched to sleep waiting status.
2. Sleep waiting status

Process to stop CAN communication is activated.

All systems controlled by IPDM E/R are stopped. When 1 second has elapsed after CAN communica-
tion with other control units is stopped, mode switches to sleep status.
3. Sleep status

IPDM E/R operates in low current-consumption mode.

CAN communication is stopped.

When a change in CAN communication signal is detected, mode switches to CAN communication sta-
tus.

When a change in ignition switch signal is detected, mode switches to CAN communication status.
CAN Communication System DescriptionEKS00BN3
Refer to LAN-5, "CAN COMMUNICATION" .
Function of Detecting Ignition Relay MalfunctionEKS00BN4

When the integrated ignition relay is stuck in a "closed contact" position and cannot be turned OFF, IPDM
E/R turns ON tail and parking lamps for 10 minutes to indicate IPDM E/R malfunction.

When the state of the integrated ignition relay does not agree with the state of the ignition switch signal
received via CAN communication, the IPDM E/R activates the tail lamp relay.
NOTE:
When the ignition switch is turned ON, the tail lamps are OFF.
A/C compressor A/C compressor OFF
Front fog lamps Front fog lamp relay OFFControlled system Fail-safe mode
Ignition switch signal Ignition relay status Tail lamp relay
ON ON —
OFF OFF —
ON OFF —
OFF ON ON (10 minutes)

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CONSULT-II Function IPDM E/REKS00BN5
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II BASIC OPERATION
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.
1. With the ignition switch OFF, connect CONSULT-II and CON-
SULT-II CONVERTER to the data link connector, then turn igni-
tion switch ON.
2. Touch “START (NISSAN BASED VHCL)”.
3. Touch “IPDM E/R” on “SELECT SYSTEM” screen.

If “IPDM E/R” is not displayed, print "SELECT SYSTEM"
screen, then refer to GI-39, "
CONSULT-II Data Link Connec-
tor (DLC) Circuit" .
Inspection Item, Diagnosis Mode Description
SELF-DIAG RESULTS The IPDM E/R performs diagnosis of CAN communication and self-diagnosis.
DATA MONITOR The input/output data of the IPDM E/R is displayed in real time.
ACTIVE TEST The IPDM E/R sends a drive signal to electronic components to check their operation.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
BBIA0369E
BCIA0029E
BCIA0030E

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IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
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4. Select “SELF-DIAG RESULTS” or “DATA MONITOR”.
SELF-DIAGNOSTIC RESULTS
Operation Procedure
1. Touch “SELF-DIAG RESULTS” on “SELECT DIAG MODE”
screen.
2. Self-diagnosis results are displayed.
Display Item List
NOTE:
The details for display of the period are as follows:

CRNT: Error currently detected with IPDM E/R.

PAST: Error detected in the past and placed in IPDM E/R memory.
DATA MONITOR
Operation Procedure
1. Touch “DATA MONITOR” on “SELECT DIAG MODE” screen.
2. Touch "ALL SIGNALS”, “MAIN SIGNALS” or “SELECT FROM MENU” on the “DATA MONITOR” screen.
3. Touch “START”.
4. Touch the required monitoring item on "SELECT ITEM MENU".
5. Touch “RECORD” while monitoring to record the status of the item being monitored. To stop recording,
touch “STOP”.
BCIA0031E
WKIA1264E
Display itemsCONSULT-II
display codeMalfunction detectionTIME
Possible
causes
CRNT PAST
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED.—————
CAN COMM CIRC U1000

If CAN communication reception/transmission
data has a malfunction, or if any of the control
units fail, data reception/transmission cannot be
confirmed.

When the data in CAN communication is not
received before the specified time.XXAny of items
listed below
have errors:

TRANSMIT
DIAG

ECM

BCM/SEC
ALL SIGNALS All signals will be monitored.
MAIN SIGNALS Monitors the predetermined item(s).
SELECT FROM MENU Selects and monitors individual signal(s).

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All Signals, Main Signals, Select 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
SIGNALSSELECT
FROM MENU
Motor fan requestMOTOR FAN
REQ1/2/3/4 X X X Signal status input from ECM
Compressor
requestAC COMP REQ ON/OFF X X X Signal status input from ECM
Tail & clear
requestTAIL & CLR REQ ON/OFF X X X Signal status input from BCM
H/L LO request HL LO REQ ON/OFF X X X Signal status input from BCM
H/L HI request HL HI REQ ON/OFF X X X Signal status input from BCM
FR fog request FR FOG REQ ON/OFF X X X Signal status input from BCM
FR 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
switchOIL P SW OPEN/CLOSE X XSignal status input from IPDM
E/R
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 ON, LO ON), 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, HI ON, LO ON, TAIL ON, FOG ON), the
lamp relay (Low, High, Tail, Fog) can be operated.

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IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
Revision: October 20052005 QX56
Auto Active TestEKS00BN6
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-92, "
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

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
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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

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IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
Revision: October 20052005 QX56
SchematicEKS00BN7
WKWA2630E

IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE ROOM)
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IPDM E/R Terminal ArrangementEKS00BN8
WKIA1986E