2005 INFINITI FX35 heater

EC-464
[VQ35DE]
DTC P1148, P1168 CLOSED LOOP CONTROL
Revision: 2005 July 2005 FX
DTC P1148, P1168 CLOSED LOOP CONTROLPFP:22690
On Board Diagnosis LogicABS006UW
These self-diagnoses have the one trip detection logic.
DTC P1148 or P1168 is displayed with another DTC for air fuel ratio (A/F) sensor 1.
Perform the trouble diagnosis for the corresponding DTC.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1148
1148
(Bank 1) Closed loop control
function The closed loop control function for bank 1
does not operate even when vehicle is driving
in the specified condition.

Harness or connectors
[The air fuel ratio (A/F) sensor 1 circuit is
open or shorted.]

Air fuel ratio (A/F) sensor 1

Air fuel ratio (A/F) sensor 1 heater
P1168
1168
(Bank 2) The closed loop control function for bank 2
does not operate even when vehicle is driving
in the specified condition.

EC-488
[VQ35DE]
DTC P1271, P1281 A/F SENSOR 1
Revision: 2005 July 2005 FX
DTC P1271, P1281 A/F SENSOR 1PFP:22693
Component DescriptionABS00A9T
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 ModeABS00A9U
Specification data are reference values.
On Board Diagnosis LogicABS00A9V
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 low.
DTC Confirmation ProcedureABS00A9W
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
P1271
1271
(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 con-
stantly approx. 0V.
Harness or connectors
(The air fuel ratio (A/F) sensor 1 cir-
cuit is open or shorted.)

Air fuel ratio (A/F) sensor 1
P1281
1281
(Bank 2)

DTC P1272, P1282 A/F SENSOR 1 EC-497
[VQ35DE]
C
D E
F
G H
I
J
K L
M A
EC
Revision: 2005 July 2005 FX
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)

EC-506
[VQ35DE]
DTC P1273, P1283 A/F SENSOR 1
Revision: 2005 July 2005 FX
DTC P1273, P1283 A/F SENSOR 1PFP:22693
Component DescriptionABS00AA7
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 ModeABS00AA8
Specification data are reference values.
On Board Diagnosis LogicABS00AA9
To judge the malfunction, the A/F signal computed by ECM from the air fuel ratio (A/F) sensor 1 signal is mon-
itored not to be shifted to LEAN side or RICH side.
DTC Confirmation ProcedureABS00AAA
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. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON- SULT-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
P1273
1273
(Bank 1) Air fuel ratio (A/F) sensor 1
lean shift monitoring

The output voltage computed by ECM from the
air fuel ratio (A/F) sensor 1 signal is shifted to
the lean side for a specified period.

Air fuel ratio (A/F) sensor 1

Air fuel ratio (A/F) sensor 1 heater

Fuel pressure

Fuel injector

Intake air leaks
P1283
1283
(Bank 2)

EC-514
[VQ35DE]
DTC P1273, P1283 A/F SENSOR 1
Revision: 2005 July 2005 FX
6. 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 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to EC-412, "
Component Inspection" .
OK or NG
OK >> GO TO 8.
NG >> Replace air fuel ratio (A/F) sensor 1.
8. CHECK INTERMITTENT INCIDENT
Perform EC-163, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace.
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.

EC-516
[VQ35DE]
DTC P1274, P1284 A/F SENSOR 1
Revision: 2005 July 2005 FX
DTC P1274, P1284 A/F SENSOR 1PFP:22693
Component DescriptionABS00AAE
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 ModeABS00AAF
Specification data are reference values.
On Board Diagnosis LogicABS00AAG
To judge the malfunction, the A/F signal computed by ECM from the air fuel ratio (A/F) sensor 1 signal is mon-
itored not to be shifted to LEAN side or RICH side.
DTC Confirmation ProcedureABS00AAH
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. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON- SULT-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
P1274
1274
(Bank 1) Air fuel ratio (A/F) sensor 1
rich shift monitoring

The A/F signal computed by ECM from the
air fuel ratio (A/F) sensor 1 signal is shifted
to the rich side for a specified period.

Air fuel ratio (A/F) sensor 1

Air fuel ratio (A/F) sensor 1 heater

Fuel pressure

Fuel Injector
P1284
1244
(Bank 2)

EC-524
[VQ35DE]
DTC P1274, P1284 A/F SENSOR 1
Revision: 2005 July 2005 FX
7. 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 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to EC-412, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace air fuel ratio (A/F) sensor 1.
9. CHECK INTERMITTENT INCIDENT
Perform EC-163, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
OK or NG
OK >> GO TO 10.
NG >> Repair or replace.
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.

EC-526
[VQ35DE]
DTC P1276, P1286 A/F SENSOR 1
Revision: 2005 July 2005 FX
DTC P1276, P1286 A/F SENSOR 1PFP:22693
Component DescriptionABS00AAL
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 ModeABS00AAM
Specification data are reference values.
On Board Diagnosis LogicABS00AAN
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 fluctuates according to fuel feedback control.
DTC Confirmation ProcedureABS00AAO
CAUTION:
Always drive vehicle at a safe speed.
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.
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
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
P1276
1276
(Bank 1) Air fuel ratio (A/F) sensor 1
circuit high voltage

The A/F signal computed by ECM from the air
fuel ratio (A/F) sensor 1 signal is constantly
approx. 1.5V.
Harness or connectors
(The air fuel ratio (A/F) sensor 1 cir-
cuit is open or shorted.)

Air fuel ratio (A/F) sensor 1
P1286
1286
(Bank 2)