INFINITI QX4 2001 Factory Service Manual
QX4 2001
INFINITI
INFINITI
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INFINITI QX4 2001 Factory Service Manual
Page 1032 of 2395

4 CHECK SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH INPUT SIGNAL CIRCUIT FOR
OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 55 and swirl control valve control vacuum check 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 5.
NG©Repair open circuit, short to ground or short to power in harness connectors.
5 CHECK SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
1. Turn ignition switch ªOFFº.
2. Disconnect vacuum hose connected to swirl control valve control vacuum check switch.
3. Attach vacuum pump to swirl control valve control vacuum check switch.
4. Turn ignition switch ªONº.
5. Check voltage between ECM terminal 55 and ground under the following conditions.
SEF709X
OK or NG
OK©GO TO 6.
NG©Replace swirl control valve control vacuum check switch.
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DTC P1165 SWIRL CONTROL VALVE CONTROL VACUUM CHECK SWITCH
Diagnostic Procedure (Cont'd)
EC-497
Page 1036 of 2395
Wiring DiagramNBEC0290
MEC969C
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DTC P1320 IGNITION SIGNAL
Wiring Diagram
EC-501
Page 1037 of 2395
MEC970C
DTC P1320 IGNITION SIGNAL
Wiring Diagram (Cont'd)
EC-502
Page 1038 of 2395
MEC971C
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DTC P1320 IGNITION SIGNAL
Wiring Diagram (Cont'd)
EC-503
Page 1040 of 2395
4 CHECK IGNITION COIL POWER SUPPLY CIRCUIT-II
1. Turn ignition switch OFF.
2. Disconnect condenser harness connector.
SEF008Z
3. Turn ignition switch ON.
4. Check voltage between condenser terminal 1 and ground with CONSULT-II or tester.
SEF367X
OK or NG
OK©GO TO 10.
NG©GO TO 5.
5 CHECK IGNITION COIL POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF.
2. Disconnect ECM relay.
SEF009Z
3. Check harness continuity between ECM relay terminal 3 and condenser terminal 1. 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 7.
NG©GO TO 6.
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DTC P1320 IGNITION SIGNAL
Diagnostic Procedure (Cont'd)
EC-505
Page 1042 of 2395
10 CHECK CONDENSER GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between condenser terminal 2 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to power.
OK or NG
OK©GO TO 11.
NG©Repair open circuit or short to power in harness or connectors.
11 CHECK CONDENSER
Check resistance between condenser terminals 1 and 2.
SEF369X
OK or NG
OK©GO TO 12.
NG©Replace condenser.
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DTC P1320 IGNITION SIGNAL
Diagnostic Procedure (Cont'd)
EC-507
Page 1043 of 2395
12 CHECK IGNITION COIL POWER SUPPLY CIRCUIT-V
1. Turn ignition switch OFF.
2. Reconnect harness connectors disconnected.
3. Disconnect ignition coil harness connector.
SEF975Y
4. Turn ignition switch ON.
5. Check voltage between ignition coil terminal 3 and ground with CONSULT-II or tester.
SEF370X
OK or NG
OK©GO TO 14.
NG©GO TO 13.
13 DETECT MALFUNCTIONING PART
Check the harness for open or short between ignition coil and harness connector F22.
©Repair or replace harness or connectors.
14 CHECK IGNITION COIL GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between ignition coil terminal 2 and engine ground. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to power.
OK or NG
OK©GO TO 15.
NG©Repair open circuit or short to power in harness or connectors.
DTC P1320 IGNITION SIGNAL
Diagnostic Procedure (Cont'd)
EC-508
Page 1044 of 2395
15 CHECK IGNITION COIL OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminals 21, 22, 23, 30, 31, 32 and ignition coil 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 16.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
16 CHECK IGNITION COIL WITH POWER TRANSISTOR
Check resistance between ignition coil terminals 2 and 3.
SEF371X
OK or NG
OK©GO TO 17.
NG©Replace ignition coil with power transistor.
17 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
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DTC P1320 IGNITION SIGNAL
Diagnostic Procedure (Cont'd)
EC-509
Page 1048 of 2395
Wiring DiagramNBEC0579
MEC960C
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DTC P1335 CRANKSHAFT POSITION SENSOR (CKPS) (REF)
Wiring Diagram
EC-513
Page 1049 of 2395
Diagnostic ProcedureNBEC0580
1 RETIGHTEN GROUND SCREWS
1. Turn ignition switch ªOFFº.
2. Loosen and retighten engine ground screws.
SEF959Y
©GO TO 2.
2 CHECK CKPS (REF) INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect CKPS (REF) harness connector.
SEF011Z
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminals 65, 75 and CKPS (REF) 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 4.
NG©GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E132, E135
IHarness connectors E116, M114 and M32, F23
IHarness for open or short between crankshaft position sensor (REF) and ECM
©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P1335 CRANKSHAFT POSITION SENSOR (CKPS) (REF)
Diagnostic Procedure
EC-514