air INFINITI FX35 2005 Service Manual

DTC P1276, P1286 A/F SENSOR 1 EC-527
[VQ35DE]
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Revision: 2005 July 2005 FX
If the indication is constantly approx. 1.5V and does not fluctuates, go to EC-532, "Diagnostic Procedure" .
If the indication fluctuates around 1.5V, go to next step.
4. Select “A/F SEN1 (B1) P1276” or “A/F SEN1 (B2) P1286” of “A/F SEN1” in “DTC WORK SUPPORT” mode with CONSULT-II.
5. Touch “START”.
6. When the following conditions are met, “TESTING” will be dis- played on the CONSULT-II screen.
If “TESTING” is not displayed after 20 seconds, retry from
step 2.
7. Release accelerator pedal fully. NOTE:
Never apply brake during releasing the accelerator pedal.
8. Make sure that “TESTING” changes to “COMPLETED”. If “TESTING” changed to “OUT OF CONDITION”, retry from
step 6.
9. Make sure that “OK” is displayed after touching “SELF-DIAG RESULT”.
If “NG” is displayed, go to EC-532, "
Diagnostic Procedure" .
Overall Function CheckABS00AAP
Use this procedure to check the overall function of the air fuel ratio (A/F) sensor 1 circuit.During this check, a
1st trip DTC might not be confirmed.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in the suitable gear position.
3. Set D position, then release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (30 MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.
4. Repeat steps 2 to 3 for 5 times.
5. Stop the vehicle and turn ignition switch OFF.
6. Wait at least 10 seconds and restart engine.
7. Repeat steps 2 to 3 for 5 times.
ENG SPEED 1,100 - 3,200 rpm
VHCL SPEED SE More than 64 km/h (40 MPH)
B/FUEL SCHDL 1.0 - 8.0 msec
Selector lever D position
SEF576Z
SEF577Z
SEF578Z

EC-532
[VQ35DE]
DTC P1276, P1286 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 ProcedureABS00AAR
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. 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

DTC P1276, P1286 A/F SENSOR 1 EC-533
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Revision: 2005 July 2005 FX
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

EC-534
[VQ35DE]
DTC P1276, P1286 A/F SENSOR 1
Revision: 2005 July 2005 FX
4. CHECK AIR FUEL RATIO (A/F) SENSOR 1 INPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between the following terminals. Refer to Wiring Diagram.
4. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
5. 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.
5. CHECK INTERMITTENT INCIDENT
Perform EC-163, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 6.
NG >> Repair or replace.
6. REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
CAUTION:

Discard any air fuel ratio (A/F) 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.

Before installing new air fuel ratio (A/F) sensor, clean exhaust system threads using Heated Oxy-
gen Sensor Thread Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
>> INSPECTION END
A/F sensor 1 terminal ECM terminal
Bank1 116
275
535
656
Bank 2 176
277
557
658
Continuity should exist.
Bank 1 Bank 2
A/F sensor 1 terminal ECM terminal A/F sensor 1 terminal ECM terminal 116176
275277
535557
656658
Continuity should not exist.

DTC P1276, P1286 A/F SENSOR 1 EC-535
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Revision: 2005 July 2005 FX
Removal and InstallationABS00AAS
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-26, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .

EC-536
[VQ35DE]
DTC P1278, P1288 A/F SENSOR 1
Revision: 2005 July 2005 FX
DTC P1278, P1288 A/F SENSOR 1PFP:22693
Component DescriptionABS00AAT
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the air fuel ratio (A/F) sensor 1 is the
combination of a Nernst concentration cell (sensor cell) with an oxy-
gen-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 1 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 ModeABS00AAU
Specification data are reference values.
On Board Diagnosis LogicABS00AAV
To judge the malfunction of air fuel ratio (A/F) sensor 1, this diagnosis measures response time of the A/F sig-
nal computed by ECM from the air fuel ratio (A/F) sensor 1 signal. The time is compensated by engine operat-
ing (speed and load), fuel feedback control constant, and the air fuel ratio (A/F) sensor 1 temperature index.
Judgment is based on whether the compensated time (the A/F signal cycling time index) is inordinately long or
not.
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
P1278
1278
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit slow response

The response (from RICH to LEAN) of the A/F
signal computed by ECM from air fuel ratio (A/
F) sensor 1 signal takes more than the speci-
fied time.

Harness or connectors
(The air fuel ratio (A/F) sensor 1 cir-
cuit is open or shorted.)

Air fuel ratio (A/F) sensor 1

Air fuel ratio (A/F) sensor 1 heater

Fuel pressure

Fuel injector

Intake air leaks

Exhaust gas leaks

PCV

Mass air flow sensor
P1288
1288
(Bank 2)

EC-538
[VQ35DE]
DTC P1278, P1288 A/F SENSOR 1
Revision: 2005 July 2005 FX

Intake air leaks

Exhaust gas leaks

Incorrect fuel pressure

Lack of fuel

Fuel Injector

Incorrect PCV hose connection

PCV valve

Mass air flow sensor
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for about 1 minute.
9. Select Service $07 with GST and make sure that no DTC is displayed. If the DTC is displayed, go to EC-542, "
Diagnostic Procedure" .

EC-542
[VQ35DE]
DTC P1278, P1288 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 ProcedureABS00AAY
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-170, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. RETIGHTEN AIR FUEL RATIO (A/F) SENSOR 1
Loosen and retighten the air fuel ratio (A/F) sensor 1.
>> GO TO 3.
TER-
MINAL 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
Tightening torque: 40 - 60 N-m (4.1 - 6.1 kg-m, 30 - 44 ft-lb)
PBIB2200E

DTC P1278, P1288 A/F SENSOR 1 EC-543
[VQ35DE]
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Revision: 2005 July 2005 FX
3. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst 1.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace.
PBIB1922E

EC-544
[VQ35DE]
DTC P1278, P1288 A/F SENSOR 1
Revision: 2005 July 2005 FX
5. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR” or “START”.
4. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171, P172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con- nector.
6. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-68, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-248, "DTC
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION" or EC-258, "DTC P0172, P0175 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 6.
SEF968Y
PBIB1565E