diagram INFINITI QX4 2001 Factory Service Manual

6 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F100, F5
IHarness for open or short between harness connector F5 and ECM
IHarness for open or short between harness connector F100 and injector
©Repair open circuit or short to ground or short to power in harness or connectors.
7 CHECK SUB-HARNESS CIRCUIT FOR OPEN AND SHORT
1. Remove intake manifold collector.
2. Disconnect injector harness connectors.
3. Check harness continuity between the following terminals. Refer to Wiring Diagram.
MTBL0483
Continuity should exist.
OK or NG
OK©GO TO 8.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
8 CHECK INJECTOR
1. Disconnect injector harness connector.
2. Check resistance between terminals as shown in the figure.
SEF964XC
OK or NG
OK©GO TO 9.
NG©Replace injector.
9 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
INJECTOR
Diagnostic Procedure (Cont'd)
EC-620

Wiring Diagram=NBEC0390
MEC975C
START SIGNAL
Wiring Diagram
EC-622

Wiring DiagramNBEC0396
MEC976C
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
FUEL PUMP
Wiring Diagram
EC-627

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.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
FUEL PUMP
Diagnostic Procedure (Cont'd)
EC-631

Wiring DiagramNBEC0401
MEC977C
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
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.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
POWER STEERING OIL PRESSURE SWITCH
Diagnostic Procedure (Cont'd)
EC-637

Wiring DiagramNBEC0637
MEC982C
REFRIGERANT PRESSURE SENSOR
Wiring Diagram
EC-640

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

Wiring DiagramNBEC0604
MEC421D
ELECTRICAL LOAD SIGNAL
Wiring Diagram
EC-644

Wiring DiagramNBEC0407
MEC978C
MIL & DATA LINK CONNECTORS
Wiring Diagram
EC-648