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EC-496
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DTC P1271, P1281 A/F SENSOR 1
Revision: 2005 July 2005 FX
Removal and InstallationABS00A9Z
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-26, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
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![INFINITI FX35 2005 Service Manual DTC P1272, P1282 A/F SENSOR 1 EC-497
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DTC P1272, P1282 A/F SENSOR 1PFP:22693
Component DescriptionABS00AA0
The air fuel rati INFINITI FX35 2005 Service Manual DTC P1272, P1282 A/F SENSOR 1 EC-497
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DTC P1272, P1282 A/F SENSOR 1PFP:22693
Component DescriptionABS00AA0
The air fuel rati](/manual-img/42/57020/w960_57020-1889.png)
DTC P1272, P1282 A/F SENSOR 1 EC-497
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DTC P1272, P1282 A/F SENSOR 1PFP:22693
Component DescriptionABS00AA0
The air fuel ratio (A/F) sensor is a planar dual-cell limit current sen-
sor. The sensor element of the air fuel ratio (A/F) sensor is the com-
bination of a Nernst concentration cell (sensor cell) with an oxygen-
pump cell, which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 < < air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the air fuel ratio (A/F) sen-
sor is able to indicate air/fuel ratio by this pumping of current. In
addition, a heater is integrated in the sensor to ensure the required
operating temperature of 700 - 800 °C (1,292 - 1,472 °F).
CONSULT-II Reference Value in Data Monitor ModeABS00AA1
Specification data are reference values.
On Board Diagnosis LogicABS00AA2
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the air fuel ratio (A/
F) sensor 1 signal is not inordinately high.
DTC Confirmation ProcedureABS00AA3
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B2)” in “DATA MONITOR” mode with CONSULT-II.
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
Engine: After warming up Maintaining engine speed at
2,000 rpm Fluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1272
1272
(Bank 1) Air fuel ratio (A/F) sensor 1
circuit no activity detected
The A/F signal computed by ECM from the air
fuel ratio (A/F) sensor 1 signal is constantly
approx. 5V.Harness or connectors
(The air fuel ratio (A/F) sensor 1 cir-
cuit is open or shorted.)
Air fuel ratio (A/F) sensor 1
P1282
1282
(Bank 2)
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EC-498
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DTC P1272, P1282 A/F SENSOR 1
Revision: 2005 July 2005 FX
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
If the indication is constantly approx. 5V, go to EC-502, "
Diag-
nostic Procedure" .
If the indication is not constantly approx. 5V, go to next step.
4. Turn ignition switch OFF, wait at least 10 seconds and then restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH) within 20 seconds after restarting engine.
6. Maintain the following conditions for about 20 consecutive sec- onds.
NOTE:
Keep the accelerator pedal as steady as possible during the cruising.
If this procedure is not completed within 1 minute after restarting engine at step 4, return to step
4.
7. If 1st trip DTC is displayed, go to EC-502, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
ENG SPEED 1,000 - 3,200 rpm
VHCL SPEED SE More than 40 km/h (25 MPH)
B/FUEL SCHDL 1.5 - 9.0 msec
Gear position Suitable position
SEF581Z
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Wiring DiagramABS00AA4
BANK 1
TBWM0390E
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EC-500
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DTC P1272, P1282 A/F SENSOR 1
Revision: 2005 July 2005 FX
Specification 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
COLOR ITEM CONDITION DATA (DC Voltage)
16 G A/F sensor 1 (Bank 1) [Engine is running]
Warm-up condition
Idle speed Approximately 3.1V
35 B/R Approximately 2.6V
56 L Approximately 2.3V
75 R/B Approximately 2.3V
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DTC P1272, P1282 A/F SENSOR 1 EC-501
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BANK 2
TBWM0391E
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EC-502
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DTC P1272, P1282 A/F SENSOR 1
Revision: 2005 July 2005 FX
Specification 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.
Diagnostic ProcedureABS00AA5
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws.Refer to EC-170, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TERMI-
NAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
57 G A/F sensor 1 (Bank 2) [Engine is running]
Warm-up condition
Idle speed Approximately 2.6V
58 Y Approximately 2.3V
76 P Approximately 3.1V
77 BR Approximately 2.3V
PBIB2625E
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2. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check voltage between air fuel ratio (A/F) sensor 1 terminal 3 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E18, F48
Fuse block (J/B) connector E201
10A fuse
Harness for open or short between air fuel ratio (A/F) sensor 1 and fuse
>> Repair or replace harness or connectors.
Voltage: Battery voltage
PBIB2190E
PBIB1683E