IDX INFINITI QX4 2001 Factory Service Manual

9 CHECK FUEL PUMP POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect fuel level sensor unit and fuel pump harness connector.
SEF021S
3. Check harness continuity between fuel pump terminal 2 and body ground, fuel pump terminal 1 and fuel pump relay-1
terminal 5. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 11.
NG©GO TO 10.
10 DETECT MALFUNCTIONING PART
Check harness for open or short between fuel pump relay and fuel pump.
©Repair open circuit or short to ground or short to power in harness or connectors.
11 CHECK FUEL PUMP RELAY OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 28 and fuel pump relay-1 terminal 1. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 13.
NG©GO TO 12.
12 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E1, M1
IHarness connectors M32, F23
IHarness for open or short between ECM and fuel pump relay-1
©Repair open circuit or short to ground or short to power in harness or connectors.
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FUEL PUMP
Diagnostic Procedure (Cont'd)
EC-631

15 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION ENDGI
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FUEL PUMP
Diagnostic Procedure (Cont'd)
EC-633

Wiring DiagramNBEC0401
MEC977C
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POWER STEERING OIL PRESSURE SWITCH
Wiring Diagram
EC-635

4 CHECK POWER STEERING OIL PRESSURE SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect power steering oil pressure switch harness connector.
SEF028Z
3. Check harness continuity between power steering oil pressure switch terminal 2 and engine ground. Refer to Wiring
Diagram.
Continuity should exist.
4. Also check harness for short to power.
OK or NG
OK©GO TO 5.
NG©Repair open circuit or short to power in harness or connectors.
5 CHECK POWER STEERING OIL PRESSURE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 47 and power steering oil pressure switch terminal 1. Refer to Wiring
Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 6.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK POWER STEERING OIL PRESSURE SWITCH
1. Disconnect power steering oil pressure switch harness connector then start engine.
2. Check continuity between power steering oil pressure switch terminals 1 and 2 under the following conditions.
SEF364X
OK or NG
OK©GO TO 7.
NG©Replace power steering oil pressure switch.
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POWER STEERING OIL PRESSURE SWITCH
Diagnostic Procedure (Cont'd)
EC-637

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-
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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

Diagnostic ProcedureNBEC0638
1 CHECK REFRIGERANT PRESSURE SENSOR OVERALL FUNCTION
1. Start engine and warm it up to normal operating temperature.
2. Turn A/C switch and blower switch ªONº.
3. Check voltage between ECM terminal 81 and ground with CONSULT-II or tester.
SEF617XA
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 CHECK REFRIGERANT PRESSURE SENSOR POWER SUPPLY CIRCUIT
1. Turn A/C switch and blower switch ªOFFº.
2. Stop engine.
3. Disconnect refrigerant pressure sensor harness connector.
SEF029Z
4. Turn ignition switch ªONº.
5. Check voltage between refrigerant pressure sensor terminal 1 and ground with CONSULT-II or tester.
SEF030Z
OK or NG
OK©GO TO 4.
NG©GO TO 3.
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REFRIGERANT PRESSURE SENSOR
Diagnostic Procedure
EC-641

ECM Terminals and Reference ValueNBEC0690Specification 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-
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NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
52 PU Electrical load signal[Engine is running]
IRear window defogger: ON
IHi-beam headlamp: ONBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
IElectrical load: OFF0V
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ELECTRICAL LOAD SIGNAL
ECM Terminals and Reference Value
EC-643

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.
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ELECTRICAL LOAD SIGNAL
Diagnostic Procedure
EC-645

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

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
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SERVICE DATA AND SPECIFICATIONS (SDS)
Fuel Pressure Regulator
EC-649