diagram INFINITI QX4 2001 Factory Manual Online

8 CHECK THROTTLE POSITION SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 91 and throttle position sensor terminal 2.
Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK (With CONSULT-II)©GO TO 9.
OK (Without CONSULT-
II)©GO TO 10.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
9 CHECK THROTTLE POSITION SENSOR
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Stop engine (ignition switch OFF).
3. Remove the vacuum hose connected to the throttle opener.
4. Connect suitable vacuum hose to the vacuum pump and the opener.
5. Apply vacuum [more than ±40.0kPa (±300mmHg, ±11.81inHg)] until the throttle drum becomes free from the rod of the
throttle opener.
SEF793W
6. Turn ignition switch ON.
7. Select ªDATA MONITORº mode with CONSULT-II.
8. Check voltage of ªTHRTL POS SENº under the following conditions.
Voltage measurement must be made with throttle position sensor installed in vehicle.
SEF062Y
OK or NG
OK©GO TO 12.
NG©GO TO 11.
GI
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PD
AX
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DTC P0120 THROTTLE POSITION SENSOR
Diagnostic Procedure (Cont'd)
EC-183

Wiring DiagramNBEC0084
MEC945C
GI
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DTC P0125 ENGINE COOLANT TEMPERATURE SENSOR (ECTS)
Wiring Diagram
EC-189

Diagnostic ProcedureNBEC0085
1 CHECK ECTS POWER SUPPLY CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect engine coolant temperature sensor harness connector F112, F28.
SEF370Z
3. Turn ignition switch ªONº.
4. Check voltage between ECTS harness connector F28 terminal 3 and ground with CONSULT-II or tester.
SEF371Z
OK or NG
OK©GO TO 3.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
2 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F112, F28
IHarness for open or short between ECM and engine coolant temperature sensor
©Repair harness or connectors.
3 CHECK ECTS GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check harness continuity between ECTS 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 5.
NG©GO TO 4.
DTC P0125 ENGINE COOLANT TEMPERATURE SENSOR (ECTS)
Diagnostic Procedure
EC-190

Wiring Diagram=NBEC0092RIGHT BANKNBEC0092S01
MEC947C
DTC P0130, P0150 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(CIRCUIT)
Wiring Diagram
EC-196

LEFT BANKNBEC0092S02
MEC948C
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DTC P0130, P0150 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(CIRCUIT)
Wiring Diagram (Cont'd)
EC-197

2 CHECK HO2S1 (FRONT) INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal and HO2S1 terminal as follows.
Refer to Wiring Diagram.
MTBL0471
Continuity should exist.
3. Check harness continuity between ECM terminal or HO2S1 terminal and ground as follows.
Refer to Wiring Diagram.
MTBL0472
Continuity should not exist.
4. Also check harness for short to power.
OK or NG
OK (With CONSULT-II)©GO TO 3.
OK (Without CONSULT-
II)©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 P0130, P0150 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(CIRCUIT)
Diagnostic Procedure (Cont'd)
EC-199

Wiring DiagramNBEC0114RIGHT BANKNBEC0114S01
MEC947C
DTC P0133, P0153 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(RESPONSE MONITORING)
Wiring Diagram
EC-222

LEFT BANKNBEC0114S02
MEC948C
GI
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PD
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SU
BR
ST
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BT
HA
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DTC P0133, P0153 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(RESPONSE MONITORING)
Wiring Diagram (Cont'd)
EC-223

7 CHECK HO2S1 (FRONT) INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal and front HO2S terminal as follows.
Refer to Wiring Diagram.
MTBL0473
Continuity should exist.
3. Check harness continuity between ECM terminal or FRONT HO2S terminal and ground as follows.
Refer to Wiring Diagram.
MTBL0474
Continuity should not exist.
4. Also check harness for short to power.
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 HEATED OXYGEN SENSOR 1 HEATER (FRONT)
Check resistance between HO2S1 (front) terminals as follows.
SEF969Y
CAUTION:
Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
OK or NG
OK©GO TO 9.
NG©GO TO 13.
GI
MA
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LC
FE
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PD
AX
SU
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ST
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BT
HA
SC
EL
IDX
DTC P0133, P0153 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(RESPONSE MONITORING)
Diagnostic Procedure (Cont'd)
EC-227

Wiring DiagramNBEC0121RIGHT BANKNBEC0121S01
MEC947C
DTC P0134, P0154 HEATED OXYGEN SENSOR 1 (FRONT) (BANK 1)/(BANK 2)
(HIGH VOLTAGE)
Wiring Diagram
EC-234