2001 INFINITI QX4 Ignition harness

3 CHECK IACV-AAC VALVE OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminals and IACV-AAC valve terminals as follows.
Refer to Wiring Diagram.
MTBL0354
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 5.
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F101, F6
IHarness for open or short between IACV-AAC valve and ECM
©Repair harness connectors.
5 CHECK AIR CONTROL VALVE (POWER STEERING) OPERATION-I
1. Reconnect ECM harness connector and IACV-AAC valve harness connector.
2. Disconnect vacuum hose connected to air control valve (Power steering) at intake air duct.
3. Start engine and let it idle.
4. Check vacuum hose for vacuum existence.
SEF995Y
Vacuum slightly exists or does not exist.
OK or NG
OK©GO TO 6.
NG©Replace air control valve (Power steering).
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
Diagnostic Procedure (Cont'd)
EC-427

10 CHECK IACV-AAC VALVE-II
1. Reconnect IACV-AAC valve harness connector and ECM harness connector.
2. Turn ignition switch ªONº and ªOFFº, and ensure the IACV-AAC valve makes operating sound according to the ignition
switch position.
SEF997Y
OK or NG
OK©GO TO 12.
NG©GO TO 11.
11 REPLACE IACV-AAC VALVE
1. Replace IACV-AAC valve assembly.
2. Perform ªIdle Air Volume Learningº, EC-57.
Is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©INSPECTION END
INCMP©Follow the construction of ªIdle Air Volume Learningº.
12 CHECK TARGET IDLE SPEED
1. Turn ignition switch ªOFFº.
2. Reconnect all harness connectors and vacuum hoses.
3. Start engine and warm it up to normal operating temperature.
4. Also warm up transmission to normal operating temperature.
IFor A/T models with CONSULT-II, drive vehicle until ªFLUID TEMP SEº in ªDATA MONITORº mode of ªA/Tº system indi-
cates less than 0.9V.
IFor A/T models without CONSULT-II, drive vehicle for 10 minutes.
5. Stop vehicle with engine running.
6. Check target idle speed.
A/T: 750±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 13.
NG©Perform ªIdle Air Volume Learningº, EC-57.
13 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð AUXILIARY AIR CONTROL
(AAC) VALVE
Diagnostic Procedure (Cont'd)
EC-430

Diagnostic ProcedureNBEC0263
1 CHECK CLOSED THROTTLE POSITION SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect throttle position switch harness connector.
SEF944Y
3. Turn ignition switch ªONº.
4. Check voltage between throttle position switch terminal 5 and engine ground with CONSULT-II or tester.
SEF346X
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M32, F23
IHarness for open or short between throttle position switch and ECM
©Repair harness or connectors.
3 CHECK CLOSED THROTTLE POSITION SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 56 and throttle position switch terminal 6.
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©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
DTC P0510 CLOSED THROTTLE POSITION SWITCH
Diagnostic Procedure
EC-435

6 CHECK THROTTLE POSITION SWITCH
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch ªOFFº.
3. Remove vacuum hose connected to throttle opener.
4. Connect suitable vacuum hose to vacuum pump and the throttle opener.
5. Apply vacuum [more than þ40.0 kPa (þ300 mmHg, þ11.81 inHg)] until the throttle drum becomes free from the rod of
the throttle opener.
SEF793W
6. Disconnect closed throttle position switch harness connector.
7. Check continuity between closed throttle position switch terminals 6 and 5 under the following conditions.
Resistance measurement must be made with throttle position switch installed in vehicle.
SEF998Y
OK or NG
OK (With CONSULT-II)©GO TO 8.
OK (Without CONSULT-
II)©GO TO 9.
NG©GO TO 7.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0510 CLOSED THROTTLE POSITION SWITCH
Diagnostic Procedure (Cont'd)
EC-437

System DescriptionNBEC0264This circuit line (LAN) is used to control the smooth shifting up and down of A/T during the hard acceleration/
deceleration.
Pulse signals are exchanged between ECM and TCM (Transmission Control Module).
Be sure to erase the malfunction information such as DTC not only in TCM but also ECM after the A/T
related repair.
ECM Terminals and Reference ValueNBEC0672Specification 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-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
114 G/RCommunication line
(LAN)[Engine is running]
IIdle speedApproximately 2V
On Board Diagnosis LogicNBEC0266Malfunction is detected when ECM receives incorrect voltage from
TCM (Transmission Control Module) continuously.
Possible CauseNBEC0517IHarness or connectors
[The communication line circuit between ECM and TCM
(Transmission Control Module) is open or shorted.]
ITCM
IDead (Weak) battery
SEF058Y
DTC Confirmation ProcedureNBEC0267NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 10 seconds
before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that bat-
tery voltage is more than 10.5V at idle.
WITH CONSULT-IINBEC0267S011) Turn ignition switch ªONº.
DTC P0600 A/T COMMUNICATION LINE
System Description
EC-440

Diagnostic ProcedureNBEC0270
1 CHECK A/T CONTROL INPUT SIGNAL CIRCUIT FOR OPEN
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector and TCM (Transmission Control Module) harness connector.
SEF955Y
SEF001Z
3. Check harness continuity between ECM terminal 114 and TCM terminal 33.
Refer to Wiring Diagram.
Continuity should exist.
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTION PART
Check the following.
IHarness connectors M94, F27
IHarness for open or short between ECM and TCM (Transmission control module)
©Repair harness or connectors.
3 CHECK A/T CONTROL INPUT SIGNAL CIRCUIT FOR SHORT
1. Check harness continuity between ECM terminal 114 and ground.
Refer to Wiring Diagram.
Continuity should not exist.
2. Also check harness for short to power.
OK or NG
OK©GO TO 4.
NG©Repair short to ground or short to power in harness or connectos.
4 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P0600 A/T COMMUNICATION LINE
Diagnostic Procedure
EC-443

On Board Diagnosis LogicNBEC0700Malfunction is detected when an improper voltage is sent to the
ECM through intake valve timing control solenoid valve.
Possible CauseNBEC0701IHarness or connectors
(Intake valve timing control solenoid valve circuit is open or
shorted.)
IIntake valve timing control solenoid valve.
SEF353Z
DTC Confirmation ProcedureNBEC0702NOTE:
If ªDTC Confirmation Procedureº has been previously
conducted, always turn ignition switch ªOFFº and wait at least
10 seconds before conducting the next test.
WITH CONSULT-IINBEC0702S011) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode with CONSULT-II.
3) Maintain the following conditions for at least 5 seconds.
Engine speed More than Idle speed
Selector lever ªPº or ªNº position
4) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-455.
WITH GSTNBEC0702S02Follow the procedure ªWith CONSULT-IIº above.
D T C P 1111(RIGHT, -B1), P1136 (LEFT, -B2) INTAKE VALVE TIMING CONTROL
SOLENOID VALVE (CIRCUIT)
On Board Diagnosis Logic
EC-452

2 INTAKE VALVE TIMING CONTROL SOLENOID VALVE POWER SUPPLY CIRCUIT
1. Stop engine.
2. Disconnect intake valve timing control solenoid valve harness connector.
SEF357Z
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 MALFUNCTION PART
Check the following.
IHarness connectors M32, F23
I10A fuse
IHarness continuity between fuse and intake valve timing control solenoid valve
©Repair harness or connectors.
4 CHECK INTAKE VALVE TIMING CONTROL SOLENOID VALVE OUTPUT CIRCUIT FOR OPEN AND
SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness connectors continuity between ECM terminal 13 (Right) or 15 (Left) and terminal 2. Refer to Wiring Dia-
gram.
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.
D T C P 1111(RIGHT, -B1), P1136 (LEFT, -B2) INTAKE VALVE TIMING CONTROL
SOLENOID VALVE (CIRCUIT)
Diagnostic Procedure (Cont'd)
EC-456