check engine INFINITI QX4 2001 Factory Service Manual

2 CHECK VIAS CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT
1. Stop engine.
2. Disconnect VIAS control solenoid valve harness connector.
SEF019Z
3. Turn ignition switch ªONº.
4. Check voltage between terminal 1 and ground with CONSULT-II or tester.
SEF603X
OK or NG
OK©GO TO 4.
NG©GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M32, F23
I10A fuse
IHarness continuity between fuse and VIAS control solenoid valve
©Repair harness or connectors.
4 CHECK VIAS CONTROL SOLENOID VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 16 and terminal 2. 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 5.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
VARIABLE INDUCTION AIR CONTROL SYSTEM (VIAS)
Diagnostic Procedure (Cont'd)
EC-614

Diagnostic ProcedureNBEC0387
1 INSPECTION START
Turn ignition switch to ªSTARTº.
Is any cylinder ignited?
YesorNo
Ye s©GO TO 2.
No©GO TO 3.
2 CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine.
2. Perform ªPOWER BALANCEº in ªACTIVE TESTº mode with CONSULT-II.
SEF190Y
3. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-II
1. Start engine.
2. Listen to each injector operating sound.
MEC703B
Clicking noise should be heard.
OK or NG
OK©INSPECTION END
NG©GO TO 3.
INJECTOR
Diagnostic Procedure
EC-618

Diagnostic ProcedureNBEC0402
1 INSPECTION START
Do you have CONSULT-II?
YesorNo
Ye s©GO TO 2.
No©GO TO 3.
2 CHECK OVERALL FUNCTION
With CONSULT-II
1. Start engine.
2. Check ªPW/ST SIGNALº in ªDATA MONITORº mode with CONSULT-II under the following conditions.
SEF228Y
OK or NG
OK©INSPECTION END
NG©GO TO 4.
3 CHECK OVERALL FUNCTION
Without CONSULT-II
1. Start engine.
2. Check voltage between ECM terminal 47 and ground under the following conditions.
SEF363X
OK or NG
OK©INSPECTION END
NG©GO TO 4.
POWER STEERING OIL PRESSURE SWITCH
Diagnostic Procedure
EC-636

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

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

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.
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ELECTRICAL LOAD SIGNAL
Diagnostic Procedure
EC-645

4 CHECK REAR WINDOW DEFOGGER INPUT SIGNAL CIRCUIT FOR OPEN OR SHORT
1. Stop engine.
2. Disconnect ECM harness connector.
3. Disconnect rear window defogger relay.
4. Check harness continuity between ECM terminal 52 and rear window defogger relay terminals 7.
SEF031Z
5. Also check harness for short to ground and 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
IHarness connectors M33, F22
IDiode M37
IHarness for open and short between ECM and rear window defigger relay
©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
7 CHECK HEADLAMP FUNCTION
1. Start engine.
2. Turn the lighting switch ªONº at 1st position with high beam.
3. Check that headlamps are illuminated.
OK or NG
OK©GO TO 8.
NG©Refer to EL-60, ªHEADLAMP (FOR USA)º or EL-123, ªHEADLAMP (FOR CANADA) Ð
DAYTIME LIGHT SYSTEMº.
ELECTRICAL LOAD SIGNAL
Diagnostic Procedure (Cont'd)
EC-646

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

SYMPTOM CHARTNBEL0201S02Symptom Chart 1 (Malfunction is Indicated in
Diagnosis Mode)
NBEL0201S0201
Symptom Possible causes Repair order
Odo/trip meter indicate(s)
malfunction in Diagnosis
mode.Unified meter control unit Replace unified meter control unit.
Multiple meter/gauge indi-
cate malfunction in Diagno-
sis mode.
One of speedometer/
tachometer/fuel gauge/
water temp. gauge indi-
cates malfunction in Diag-
nosis mode.1. Meter/Gauge
2. Unified meter control unit1. Check resistance of meter/gauge indicating malfunc-
tion. If the resistance is NG, replace the meter/
gauge. Refer to ªMETER/GAUGE RESISTANCE
CHECKº, EL-108.
2. If the resistance of meter/gauge is OK, replace uni-
fied meter control unit.
Symptom Chart 2 (No Malfunction is Indicated in
Diagnosis Mode)
NBEL0201S0202
Symptom Possible causes Repair order
One of speedometer/
tachometer/fuel gauge/
water temp. gauge is mal-
functioning.1. Sensor signal
- Vehicle speed signal
- Engine revolution signal
- Fuel gauge
- Water temp. gauge
2. Unified meter control unit1. Check the sensor for malfunctioning meter/gauge.
INSPECTION/VEHICLE SPEED SENSOR (Refer to
EL-104.)
INSPECTION/ENGINE REVOLUTION SIGNAL
(Refer to EL-105.)
INSPECTION/FUEL LEVEL SENSOR UNIT (Refer to
EL-106.)
INSPECTION/THERMAL TRANSMITTER (Refer to
EL-107.)
2. Replace unified meter control unit. Multiple meter/gauge are
malfunctioning. (except
odo/trip meter)
Before starting trouble diagnoses below, perform PRELIMINARY
CHECK, EL-101.
METERS AND GAUGES
Trouble Diagnoses (Cont'd)
EL-102