2001 INFINITI QX4 ignition

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

Diagnostic ProcedureNBEC0605
1 CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I
1. Turn ignition switch ªONº.
2. Check voltage between ECM terminal 52 and ground under the following conditions.
SEF610X
OK or NG
OK©GO TO 2.
NG©GO TO 3.
2 CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II
Check voltage between ECM terminal 52 and ground under the following conditions.
SEF611X
OK or NG
OK©INSPECTION END
NG©GO TO 7.
3 CHECK REAR WINDOW DEFOGGER FUNCTION
1. Start engine.
2. Turn ªONº the rear window defogger switch.
3. Check the rear windshield. Is the rear windshield heated up?
YesorNo
Ye s©GO TO 4.
No©Refer to EL-151, ªRear Window Defoggerº.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
ELECTRICAL LOAD SIGNAL
Diagnostic Procedure
EC-645

Fuel Pressure RegulatorNBEC0408
Fuel pressure at idling kPa (kg/cm2, psi)
Vacuum hose is connected. Approximately 235 (2.4, 34)
Vacuum hose is disconnected. Approximately 294 (3.0, 43)
Idle Speed and Ignition TimingNBEC0409
Target idle speed*1 No-load*2 (in ªPº or Nº position) 750±50 rpm
Air conditioner: ON In ªPº or Nº position 825 rpm or more
Ignition timing*1 In ªPº or Nº position 15ɱ5É BTDC
Throttle position sensor idle position0.15 - 0.85V
*1: Throttle position sensor harness connector connected
*2: Under the following conditions:
IAir conditioner switch: OFF
IElectric load: OFF (Lights, heater fan & rear window defogger)
ISteering wheel: Kept in straight-ahead position
Mass Air Flow SensorNBEC0411
Supply voltageBattery voltage (11 - 14)V
Output voltage at idle1.2 - 1.8*V
Mass air flow (Using CONSULT-II or GST)2.0 - 6.0 g´m/sec at idle*
7.0 - 20.0 g´m/sec at 2,500 rpm*
*: Engine is warmed up to normal operating temperature and running under no-load.
Engine Coolant Temperature SensorNBEC0412
Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
Heated Oxygen Sensor 1 Heater (Front)NBEC0414
Resistance [at 25ÉC (77ÉF)]2.3 - 4.3W
Fuel PumpNBEC0415
Resistance [at 25ÉC (77ÉF)]0.2 - 5.0W
IACV-AAC ValveNBEC0416
Resistance [at 20ÉC (68ÉF)]Approximately 20 - 24W
InjectorNBEC0417
Resistance [at 20ÉC (68ÉF)]13.5 - 17.5W
ResistorNBEC0418
Resistance [at 25ÉC (77ÉF)]Approximately 2.2 kW
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
SERVICE DATA AND SPECIFICATIONS (SDS)
Fuel Pressure Regulator
EC-649

Throttle Position SensorNBEC0419
Throttle valve conditionsVoltage
(at normal operating temperature,
engine off, ignition switch ON,
throttle opener disengaged)
Completely closed (a)0.15 - 0.85V
Partially openBetween (a) and (b)
Completely open (b)3.5 - 4.7V
Calculated Load ValueNBEC0420
Calculated load value % (Using CONSULT-II or GST)
At idle14.0 - 33.0
At 2,500 rpm12.0 - 25.0
Intake Air Temperature SensorNBEC0421
Temperature ÉC (ÉF) Resistance kW
20 (68)2.1 - 2.9
80 (176)0.27 - 0.38
Heated Oxygen Sensor 2 Heater (Rear)NBEC0422
Resistance [at 25ÉC (77ÉF)]2.3 - 4.3W
Crankshaft Position Sensor (REF)NBEC0423
Resistance [at 20ÉC (68ÉF)]470 - 570W
Fuel Tank Temperature SensorNBEC0424
Temperature ÉC (ÉF) Resistance kW
20 (68)2.3 - 2.7
50 (122)0.79 - 0.90
Camshaft Position Sensor (PHASE)NBEC0639
Resistance [at 20ÉC (68ÉF)]HITACHI make 1,440 - 1,760W
MITSUBISHI make 2,090 - 2,550W
SERVICE DATA AND SPECIFICATIONS (SDS)
Throttle Position Sensor
EC-650

Wiring Diagram Ð POWER ÐNBEL0006BATTERY POWER SUPPLY Ð IGNITION SW. IN ANY POSITIONNBEL0006S01
MEL755L
POWER SUPPLY ROUTING
Wiring Diagram Ð POWER Ð
EL-10

ACCESSORY POWER SUPPLY Ð IGNITION SW. IN ªACCº OR ªONºNBEL0006S02
MEL758L
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
IDX
POWER SUPPLY ROUTING
Wiring Diagram Ð POWER Ð (Cont'd)
EL-13

IGNITION POWER SUPPLY Ð IGNITION SW. IN ªONº AND/OR ªSTARTºNBEL0006S03
MEL759L
POWER SUPPLY ROUTING
Wiring Diagram Ð POWER Ð (Cont'd)
EL-14

Component Parts and Harness Connector
Location
NBEL0159
SEL460X
System DescriptionNBEL0188The headlamp operation is controlled by the lighting switch which is built into the combination switch and
headlamp battery saver control unit. And the headlamp battery saver system is controlled by the headlamp
battery saver control unit and smart entrance control unit.
OUTLINENBEL0188S01Power 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)].
When the ignition switch is in the ON or START position, power is supplied
Ito headlamp battery saver control unit terminal 1
Ithrough 10A fuse [No. 16, located in the fuse block (J/B)], and
Ito headlamp battery saver control unit terminal 10,
Ito auto light control unit terminal 1 and
Ito smart entrance control unit terminal 33
Ithrough 7.5A fuse [No. 11, located in the fuse block (J/B)].
GI
MA
EM
LC
EC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
IDX
HEADLAMP (FOR USA) Ð XENON TYPE Ð
Component Parts and Harness Connector Location
EL-31