Combination INFINITI QX56 2004 Factory Owners Manual

DTC P1273, P1283 A/F SENSOR 1
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Revision: August 20072004 QX56
DTC P1273, P1283 A/F SENSOR 1PFP:22693
Component DescriptionUBS00H9T
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination 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 A/F sensor 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 tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor ModeUBS00H9U
Specification data are reference values.
On Board Diagnosis LogicUBS00H9V
To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be
shifted LEAN side or RICH side.
DTC Confirmation ProcedureUBS00H9W
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.
SEF 5 79 Z
SEF 5 80 Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates 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
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

Injector

Intake air leaks P1283
1283
(Bank 2)

EC-454Revision: August 2007
DTC P1274, P1284 A/F SENSOR 1
2004 QX56
DTC P1274, P1284 A/F SENSOR 1PFP:22693
Component DescriptionUBS00HA0
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination 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 A/F sensor 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 tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor ModeUBS00HA1
Specification data are reference values.
On Board Diagnosis LogicUBS00HA2
To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be
shifted to the LEAN side or RICH side.
DTC Confirmation ProcedureUBS00HA3
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.
SEF 5 79 Z
SEF 5 80 Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates 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
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

Injector P1284
1244
(Bank 2)

DTC P1276, P1286 A/F SENSOR 1
EC-463
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Revision: August 20072004 QX56
DTC P1276, P1286 A/F SENSOR 1PFP:22693
Component DescriptionUBS00HA7
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination 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 A/F sensor 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 tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor ModeUBS00HA8
Specification data are reference values.
On Board Diagnosis LogicUBS00HA9
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal fluctuates according to fuel feedback control.
DTC Confirmation ProcedureUBS00HAA
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.
SEF 5 79 Z
SEF 5 80 Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates 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 A/F
sensor 1 signal is constantly approx. 1.5V.

Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)

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

EC-472Revision: August 2007
DTC P1278, P1288 A/F SENSOR 1
2004 QX56
DTC P1278, P1288 A/F SENSOR 1PFP:22693
Component DescriptionUBS00HAF
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination 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 A/F sensor 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 tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor ModeUBS00HAG
Specification data are reference values.
On Board Diagnosis LogicUBS00HAH
To judge the malfunction of A/F sensor 1, this diagnosis measures response time of the A/F signal computed
by ECM from the A/F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel
feedback control constant, and the A/F sensor 1 temperature index. Judgment is based on whether the com-
pensated time (the A/F signal cycling time index) is inordinately long or not.
SEF 5 79 Z
SEF 5 80 Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming upMaintaining 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 A/F sensor 1
signal takes more than the specified time.

Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)

Air fuel ratio (A/F) sensor 1

Air fuel ratio (A/F) sensor 1 heater

Fuel pressure

Injector

Intake air leaks

Exhaust gas leaks

PCV

Mass air flow sensor P1288
1288
(Bank 2)

EC-484Revision: August 2007
DTC P1279, P1289 A/F SENSOR 1
2004 QX56
DTC P1279, P1289 A/F SENSOR 1PFP:22693
Component DescriptionUBS00HAM
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination 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 A/F sensor 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 tempera-
ture of 700 - 800°C (1,292 - 1,472°F).
CONSULT-II Reference Value in Data Monitor ModeUBS00HAN
Specification data are reference values.
On Board Diagnosis LogicUBS00HAO
To judge the malfunction of A/F sensor 1, this diagnosis measures response time of the A/F signal computed
by ECM from the air fuel ration A/F sensor 1 signal. The time is compensated by engine operating (speed and
load), fuel feedback control constant, and the 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.
SEF 5 79 Z
SEF 5 80 Z
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates around 1.5V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P1279
1279
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit slow response

The response (from LEAN to RICH) of the A/F
signal computed by ECM from A/F sensor 1
signal takes more than the specified time.

Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)

Air fuel ratio (A/F) sensor 1

Air fuel ratio (A/F) sensor 1 heater

Fuel pressure

Injector

Intake air leaks

Exhaust gas leaks

PCV

Mass air flow sensor P1289
1289
(Bank 2)

DTC P1564 ICC STEERING SWITCH
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Revision: August 20072004 QX56
2. CHECK ICC STEERING SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect combination switch harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between combination switch terminal
15 and ECM terminal 67.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M31, E152

Harness connectors E19, F33

Combination switch (spiral cable)

Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK ICC STEERING SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 99 and combination switch terminal 14.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M31, E152

Combination switch (spiral cable)

Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ICC STEERING SWITCH
Refer to EC-516, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace ICC steering switch.Continuity should exist.
BBIA0469E
Continuity should exist.

EC-516Revision: August 2007
DTC P1564 ICC STEERING SWITCH
2004 QX56
7. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00HYV
ICC STEERING SWITCH
1. Disconnect combination switch (spiral cable).
2. Check continuity between combination switch (spiral cable) ter-
minals 14 and 15 with pushing each switch.
If NG, replace ICC steering switch.
Switch Condition Resistance [Ω]
ON/OFF (MAIN) switchPressed Approx. 0
Released Approx. 5,500
COAST/SET switchPressed Approx. 1,400
Released Approx. 5,500
ACCEL/RESUME switchPressed Approx. 2,600
Released Approx. 5,500
DISTANCE switchPressed Approx. 740
Released Approx. 5,500
CANCEL switchPressed Approx. 310
Released Approx. 5,500
PBIB1673E

DTC P1564 ASCD STEERING SWITCH
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Revision: August 20072004 QX56
Diagnostic ProcedureUBS00HBD
1. CHECK ASCD STEERING SWITCH CIRCUIT
With CONSULT-II
1. Turn ignition switch ON.
2. Select “MAIN SW”, “RESUME/ACC SW”, “SET SW” and “CANCEL SW” in “DATA MONITOR” mode with
CONSULT-II.
3. Check each item indication under the following conditions.
Without CONSULT-II
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 99 and ground with press-
ing each button.
OK or NG
OK >> GO TO 7.
NG >> GO TO 2.
2. CHECK ASCD STEERING SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Disconnect combination switch harness connector.
4. Check harness continuity between combination switch terminal
15 and ECM terminal 67. Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
Switch Monitor item Condition Indication
ON/OFF(MAIN)
switchMAIN SWPressed ON
Released OFF
ACCEL/RESUME
switchRESUME/ACC SWPressed ON
Released OFF
COAST/SET switch SET SWPressed ON
Released OFF
CANCEL switch CANCEL SW Pressed ON
Released OFF
SEC0 06 D
Switch Condition Voltage [V]
ON/OFF(MAIN) switchPressed Approx. 0
Released Approx. 4
ACCEL/RESUME switchPressed Approx. 3
Released Approx. 4
COAST/SET switchPressed Approx. 2
Released Approx. 4
CANCEL switchPressed Approx. 1
Released Approx. 4
PBIB0 311 E
Continuity should exist.
BBIA0362E

EC-522Revision: August 2007
DTC P1564 ASCD STEERING SWITCH
2004 QX56
3. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M31, E152

Harness connectors E19, F33

Combination switch (spiral cable)

Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK ASCD STEERING SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 99 and combination switch terminal 14.
Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> GO TO 5.
5. DETECT MALFUNCTIONING PART
Check the following.

Harness connectors M31, E152

Combination switch (spiral cable)

Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ASCD STEERING SWITCH
Refer to EC-522, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> Replace ASCD steering switch.
7. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionUBS00HBE
ASCD STEERING SWITCH
1. Disconnect combination switch (spiral cable).
2. Check continuity between ASCD steering switch terminals 14
and 15 with pushing each switch.Continuity should exist.
Switch Condition Resistance [Ω]
ON/OFF(MAIN) switchPressed Approx. 0
Released Approx. 4,000
COAST/SET switchPressed Approx. 660
Released Approx. 4,000
PBIB1673E

DTC P1574 ICC VEHICLE SPEED SENSOR
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Revision: August 20072004 QX56
Diagnostic ProcedureUBS00HZ9
1. CHECK DTC WITH TCM
Check DTC with TCM. Refer to AT - 3 9 , "
OBD-II Diagnostic Trouble Code (DTC)" .
OK or NG
OK >> GO TO 2.
NG >> Perform trouble shooting relevant to DTC indicated.
2. CHECK DTC WITH “ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)”
Refer to BRC-11, "
TROUBLE DIAGNOSIS" .
OK or NG
OK >> GO TO 3.
NG >> Repair or replace.
3. CHECK DTC WITH “UNIFIED METER AND A/C AMP”
Refer to DI-5, "
COMBINATION METERS" .
>>INSPECTION END