Engine control INFINITI QX4 2001 Factory Service Manual

System DescriptionNBEC0392
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed (POS signal)
Fuel pump
controlFuel pump relay Crankshaft position sensor (REF) Engine speed (REF signal)
Ignition switch Start signal
The ECM activates the fuel pump for several seconds after the ignition switch is turned on to improve engine
startability. If the ECM receives a 120É signal from the crankshaft position sensor (REF), it knows that the
engine is rotating, and causes the pump to operate. If the 120É signal is not received when the ignition switch
is on, the engine stalls. The ECM stops pump operation and prevents battery discharging, thereby improving
safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn
controls the fuel pump.
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown aboveStops.
SEF018S
Component DescriptionNBEC0393The fuel pump with a fuel damper is an in-tank type (the pump and
damper are located in the fuel tank).
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0394Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FUEL PUMP RLYIIgnition switch is turned to ON. (Operates for 1 second.)
IEngine running and crankingON
Except as shown above OFF
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FUEL PUMP
System Description
EC-625

SEF029Z
DescriptionNBEC0636The refrigerant pressure sensor is installed at the liquid tank of the
air conditioner system. The sensor uses an electrostatic volume
pressure transducer to convert refrigerant pressure to voltage. The
voltage signal is sent to ECM, and ECM controls cooling fan sys-
tem.
SEF099XA
ECM Terminals and Reference ValueNBEC0689Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
58 B/P Sensors' ground[Engine is running]
IWarm-up condition
IIdle speedApproximately 0V
81 W/PURefrigerant pressure
sensor[Engine is running]
IWarm-up condition
IBoth A/C switch and blower switch are ªONº.
(Compressor operates.)1.0 - 4.0V
111 P/B Sensors' power supply[Ignition switch ªONº]Approximately 5V
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REFRIGERANT PRESSURE SENSOR
Description
EC-639

3 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E1, M1
IHarness for open or short between ECM and refrigerant pressure sensor
©Repair harness or connectors.
4 CHECK REFRIGERANT PRESSURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between refrigerant pressure sensor terminal 1 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to power.
OK or NG
OK©GO TO 6.
NG©GO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E1, M1 and M33, F22
IHarness connectors F23, M32
IHarness for open between ECM and refrigerant pressure sensor
IHarness for open between TCM (Transmission control module) and refrigerant pressure sensor
©Repair open circuit or short to power in harness or connectors.
6 CHECK REFRIGERANT PRESSURE SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 81 and refrigerant pressure sensor terminal 2. Refer to Wiring Dia-
gram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 8.
NG©GO TO 7.
7 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E1, M1 and M94, F27
IHarness for open or short between ECM and refrigerant pressure sensor
©Repair open circuit or short to ground or short to power in harness or connectors.
8 CHECK REFRIGERANT PRESSURE SENSOR
Refer to HA-14, ªRefrigerant pressure sensorº.
OK or NG
OK©GO TO 9.
NG©Replace refrigerant pressure sensor.
9 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
REFRIGERANT PRESSURE SENSOR
Diagnostic Procedure (Cont'd)
EC-642

8 CHECK HEADLAMP INPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Stop engine.
2. Disconnect ECM harness connector.
3. Disconnect headlamp LH relay.
4. Check harness continuity between ECM terminal 52 and headlamp LH relay terminal 7 under the following conditions.
SEF031Z
5. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 10.
NG©GO TO 9.
9 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E1, M1
IHarness connectors M33, F22
IDiode E121
IHarness for open and short between ECM and headlamp LH relay or daytime light control unit
©Repair open circuit or short to ground or short to power in harness or connectors.
10 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
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ELECTRICAL LOAD SIGNAL
Diagnostic Procedure (Cont'd)
EC-647

Schematic ................................................................255
Wiring Diagram - D/LOCK -.....................................256
Trouble Diagnoses...................................................261
MULTI-REMOTE CONTROL SYSTEM.......................270
Component Parts and Harness Connector
Location ...................................................................270
System Description ..................................................270
Schematic ................................................................273
Wiring Diagram - MULTI - .......................................274
Trouble Diagnoses...................................................277
ID Code Entry Procedure ........................................289
Remote Controller Battery Replacement.................293
THEFT WARNING SYSTEM.......................................294
Component Parts and Harness Connector
Location ...................................................................294
System Description ..................................................295
Schematic ................................................................298
Wiring Diagram - THEFT -.......................................300
Trouble Diagnoses...................................................306
SMART ENTRANCE CONTROL UNIT.......................319
Description ...............................................................319
Schematic ................................................................322
Smart Entrance Control Unit Inspection Table ........324
INTEGRATED HOMELINK TRANSMITTER...............325
Wiring Diagram - TRNSMT - ...................................325
Trouble Diagnoses...................................................326
IVIS (INFINITI VEHICLE IMMOBILIZER SYSTEM -
NATS)...........................................................................328
Component Parts and Harness Connetor
Location ...................................................................328
System Description ..................................................329
System Composition ................................................329
Wiring Diagram - NATS -.........................................330
CONSULT-II .............................................................331
Trouble Diagnoses...................................................334
How to Replace IVIS (NATS) IMMU .......................347
INFINITI COMMUNICATOR (IVCS)............................348
Precaution ................................................................348
Communicator Response Center Telephone
Number for Technicians ...........................................348
Component Parts and Harness Connector
Location ...................................................................349System Description ..................................................350
Schematic ................................................................358
Wiring Diagram - IVCS -..........................................359
CONSULT-II .............................................................363
Trouble Diagnoses...................................................368
Trouble Diagnoses for Intermittent Incident ............377
Demonstration Mode ...............................................379
System Setting (When IVCS Unit is Replaced) ......381
NAVIGATION SYSTEM...............................................385
Component Parts Location ......................................385
System Description ..................................................386
Schematic ................................................................393
Wiring Diagram - NAVI - ..........................................394
Self-diagnosis Mode ................................................397
Confirmation/Adjustment Mode ...............................400
Setting Mode............................................................410
Trouble diagnoses ...................................................417
This Condition is Not Abnormal ...............................423
Program Loading .....................................................432
Initialization ..............................................................433
ELECTRICAL UNITS LOCATION...............................436
Engine Compartment ...............................................436
Passenger Compartment .........................................438
HARNESS LAYOUT....................................................440
How to Read Harness Layout .................................440
Outline......................................................................441
Main Harness...........................................................442
Engine Room Harness ............................................444
Engine Control Harness ..........................................446
Body Harness LH ....................................................448
Body Harness RH ....................................................449
Back Door Harness .................................................450
Engine and Transmission Harness..........................451
Room Lamp Harness...............................................452
Air Bag Harness ......................................................453
Front Door Harness .................................................454
Rear Door Harness..................................................455
BULB SPECIFICATIONS............................................456
Headlamp.................................................................456
Exterior Lamp ..........................................................456
Interior Lamp............................................................456
WIRING DIAGRAM CODES (CELL CODES).............457GI
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CONTENTS(Cont'd)
EL-3

ENGINE CONTROL HARNESSNBEL0008S03
MEL147M
GROUND
Ground Distribution (Cont'd)
EL-22

Component Parts and Harness Connector
Location
NBEL0161
SEL460X
System DescriptionNBEL0192The headlamp system for Canada vehicles contains a daytime light control unit that activates the high beam
headlamps at approximately half illumination whenever the engine is running. If the parking brake is applied
before the engine is started the daytime lights will not be illuminated. The daytime lights will illuminate once
the parking brake is released. Thereafter, the daytime lights will continue to operate when the parking brake
is applied.
And battery saver system is controlled by the headlamp battery saver control unit and smart entrance control
unit.
Power is supplied at all times
Ito headlamp LH relay terminals 1 and 3
Ithrough 15A fuse (No. 60, located in the fuse and fusible link box), and
Ito headlamp LH relay terminal 6
Ithrough 20A fuse (No. 32, located in the fuse and fusible link box), and
Ito headlamp RH relay terminals 1 and 3
Ithrough 15A fuse (No. 59, located in the fuse and fusible link box), and
Ito headlamp RH relay terminal 6
Ithrough 20A fuse (No. 31, located in the fuse and fusible link box), and
Ito headlamp battery saver control unit terminal 7, and
Ito smart entrance control unit terminal 10
Ithrough 7.5A fuse [No. 24, located in the fuse block (J/B)].
Ground is supplied
Ito daytime light control unit terminal 16,
Ito auto light control unit terminal 5 and
Ito headlamp battery saver control unit terminals 4 and 11.
When the ignition switch is in the ON or START position, power is also supplied
HEADLAMP (FOR CANADA) Ð DAYTIME LIGHT SYSTEM Ð
Component Parts and Harness Connector Location
EL-46

BATTERY SAVER CONTROLNBEL0192S02When the ignition switch is turned from ON (or START) to OFF (or ACC) positions while headlamps are
illuminated, The RAP signal is supplied to terminal 10 of the headlamp battery saver control unit from smart
entrance control unit terminal 5.
After counting 45 seconds by the RAP signal from the smart entrance control unit to headlamp battery saver
control unit, the ground supply to terminal 2 of headlamp LH and RH relays from headlamp battery saver con-
trol unit terminals 2 and 8 is terminated.
Then headlamps are turned off.
The headlamps are turned off when LH or RH door is opened even if 45 seconds have not passed after the
ignition switch is turned from ON (or START) to OFF (or ACC) positions while headlamps are illuminated.
When the lighting switch is turned from OFF to 2ND after headlamps are turned to off by the battery saver
control, ground is supply
Ito headlamp battery saver control unit terminals 5 and 13 from lighting switch terminal 11, and
Ito headlamp LH and RH relays terminal 2 from headlamp battery saver control unit terminals 2 and 8
Ithrough headlamp battery saver control unit terminals 3 and 9, and
Ithrough lighting switch terminal 12.
Then headlamps illuminate again.
AUTO LIGHT OPERATIONNBEL0192S03For auto light operation, refer to ªHEADLAMPº (EL-33).
DAYTIME LIGHT OPERATIONNBEL0192S04With the engine running, the lighting switch in the OFF or 1ST position and parking brake released, power is
supplied
Ithrough daytime light control unit terminals 3 and 7
Ito terminal 1 of RH headlamp
Ithrough terminal 2 of RH headlamp
Ito daytime light control unit terminal 9
Ithrough daytime light control unit terminal 6
Ito terminal 1 of LH headlamp.
Ground is supplied to terminal 2 of LH headlamp.
Ithrough daytime light control unit terminals 10 and 16
Ithrough body grounds E13 and E41.
Because the high beam headlamps are now wired in series, they operate at half illumination.
HEADLAMP (FOR CANADA) Ð DAYTIME LIGHT SYSTEM Ð
System Description (Cont'd)
EL-48

Trouble DiagnosesNBEL0193DAYTIME LIGHT CONTROL UNIT INSPECTION TABLENBEL0193S01
Terminal
No.Wire
colorItem ConditionVoltage
(Approximate values)
1 Y/B Alternator
When turning ignition switch to ªONº Less than 1V
When engine is running Battery voltage
When turning ignition switch to ªOFFº Less than 1V
2 Y/R Start signal
When turning ignition switch to ªSTº Battery voltage
When turning ignition switch to ªONº from ªSTº Less than 1V
When turning ignition switch to ªOFFº Less than 1V
3 G Power source
When turning ignition switch to ªONº Battery voltage
When turning ignition switch to ªSTº Battery voltage
When turning ignition switch to ªOFFº Less than 1V
4 R/L Power source
When turning ignition switch to ªONº Battery voltage
When turning ignition switch to ªOFFº Battery voltage
5 R/W Power source
When turning ignition switch to ªONº Battery voltage
When turning ignition switch to ªOFFº Battery voltage
6 R LH hi beam When lighting switch is turned to the 2ND position with
ªHI BEAMº positionBattery voltage
When releasing parking brake with engine running and
turning lighting switch to ªOFFº (daytime light operation)
CAUTION:
Block wheels and ensure selector lever is in N or P
position.Approx. half battery
voltage
HEADLAMP (FOR CANADA) Ð DAYTIME LIGHT SYSTEM Ð
Trouble Diagnoses
EL-56

Terminal
No.Wire
colorItem ConditionVoltage
(Approximate values)
7 L/R RH hi beam When lighting switch is turned to the 2ND position with
ªHI BEAMº positionBattery voltage
When releasing parking brake with engine running and
turning lighting switch to ªOFFº (daytime light operation)
CAUTION:
Block wheels and ensure selector lever is in N or P
position.Approx. half battery
voltage
9 PU RH hi beam
(ground)When lighting switch is turned to the 2ND position with
ªHI BEAMº positionLess than 1V
When releasing parking brake with engine running and
turning lighting switch to ªOFFº (daytime light operation)
CAUTION:
Block wheels and ensure selector lever is in N or P
position.Approx. half battery
voltage
10 GY LH hi beam
(ground)When lighting switch is turned to the 2ND position with
ªHI BEAMº positionLess than 1V
When releasing parking brake with engine running and
turning lighting switch to ªOFFº (daytime light operation)
CAUTION:
Block wheels and ensure selector lever is in N or P
position.Approx. half battery
voltage
13
14L/W
W/RLighting switch
(Hi beam)When turning lighting switch to ªHI BEAMº Battery voltage
When turning lighting switch to ªFLASH TO PASSº Battery voltage
16 B Ground Ð Ð
17 L/G Parking brake
switch
When parking brake is released Battery voltage
When parking brake is set Less than 1.5V
BATTERY SAVER CONTROL UNIT INSPECTION TABLENBEL0193S02Refer to ªHEADLAMP (FOR USA)º, EL-42.
Bulb ReplacementNBEL0194Refer to ªHEADLAMP (FOR USA)º (EL-43).
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HEADLAMP (FOR CANADA) Ð DAYTIME LIGHT SYSTEM Ð
Trouble Diagnoses (Cont'd)
EL-57