2011 INFINITI QX56 turn signal

P0139, P0159 HO2S2EC-259
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
3.PERFORM COMPONENT FUNCTION CHECK-III
Check the voltage between ECM harness connector terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-259, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217823
1.CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE
1. Clear the mixture ratio self-learning value. Refer to EC-152, "
Work Procedure".
2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P0172, P0174 or P 0175 detected? Is it difficult to start engine?
YES >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-263, "DTC Logic"
or EC-267, "DTC Logic".
NO >> GO TO 2.
2.CHECK HEATED OXYGEN SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 (HO2S2) harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between HO2S2 harness connector and ECM harness connector.
5. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between HO2S2 harness connector and ECM harness connector.
2. Check the continuity between HO2S2 harness connector and ground, or ECM harness connector and
ground.
DTC ECM
Condition Voltage
Connector +–
Terminal Terminal
P0139 F110 96
100Coasting from 80 km/h (50 MPH) with se-
lector lever in the D position A change of voltage should be more than
0.24 V for 1 second during this procedure.
P0159 87
DTC HO2S2 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0139 1 F87 1 F110 100 Existed
P0159 2 F88 1
DTC HO2S2 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0139 1 F87 4 F11096
Existed
P0159 2 F88 4 87
DTC HO2S2 ECM
Ground Continuity
Bank Connector Terminal Connector Terminal
P0139 1 F87 4 F11096
Ground Not existed
P0159 2 F88 4 87
Revision: 2010 May2011 QX56

P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-263
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0171, P0174 FUEL INJE
CTION SYSTEM FUNCTION
DTC LogicINFOID:0000000006217825
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio f eedback signal from A/F sensor 1. The ECM calculates
the necessary compensation to co rrect the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extrem ely large (the actual mixture ratio is too lean), the
ECM judges the condition as the fuel injection system malfunction and illuminates the MIL (2 trip detection
logic).
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
1. Clear the mixture ratio self-learning value. Refer to EC-152, "
Work Procedure".
2. Start engine.
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the f uel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three fourths (3/4) or more, the control system does not start the engine.
Do not depress accelerator pedal too much.
Does engine start?
YES >> Proceed to EC-264, "Diagnosis Procedure".
NO >> Check exhaust and intake air leakage visually.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Keep engine idle for at least 5 minutes.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-264, "Diagnosis Procedure".
Sensor Input signal to ECM ECM function Actuator
A/F sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal) Fuel injection control Fuel injector
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0171 FUEL SYS-LEAN-B1
[Fuel injection system too
lean (bank 1)]
 Fuel injection system does not operate properly.
 The amount of mixture ratio compensation is too
large. (The mixture ratio is too lean.)  Intake air leakage
 A/F sensor 1
 Fuel injector
 Exhaust gas leakage
 Incorrect fuel pressure
 Lack of fuel
 Mass air flow sensor
 Incorrect PCV hose connection
P0174
FUEL SYS-LEAN-B2
[Fuel injection system too
lean (bank 2)]
Revision: 2010 May2011 QX56

P0172, P0175 FUEL INJECTION SYSTEM FUNCTION
EC-267
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0172, P0175 FUEL INJE
CTION SYSTEM FUNCTION
DTC LogicINFOID:0000000006217827
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio f eedback signal from A/F sensor 1. The ECM calculates
the necessary compensation to co rrect the offset between the actual and the theoretical ratios.
In case the amount of the compensation value is extremely large (the actual mixture ratio is too rich), the ECM
judges the condition as the fuel injection system malfunc tion and illuminates the MIL (2 trip detection logic).
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
1. Clear the mixture ratio self-learning value. Refer to EC-152, "
Work Procedure".
2. Start engine.
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the f uel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three fourths (3/4) or more, the control system does not start the engine.
Do not depress accelerator pedal too much.
Does engine start?
YES >> Proceed to EC-268, "Diagnosis Procedure".
NO >> Remove spark plugs and check for fouling, etc.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Keep engine idle for at least 5 minutes.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-268, "Diagnosis Procedure".
NO >> GO TO 5.
Sensor Input signal to ECM ECM function Actuator
A/F sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal) Fuel injection control Fuel injector
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0172 FUEL SYS-RICH-B1
[Fuel injection system too
rich (bank 1)]
 Fuel injection system does not operate properly.
 The amount of mixture ratio compensation is too
large. (The mixture ratio is too rich.)  A/F sensor 1
 Fuel injector
 Exhaust gas leakage
 Incorrect fuel pressure
 Mass air flow sensor
P0175 FUEL SYS-RICH-B2
[Fuel injection system too
rich (bank 2)]
Revision: 2010 May2011 QX56

P0181 FTT SENSOREC-271
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0181 FTT SENSOR
DTC LogicINFOID:0000000006288289
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
1. Turn ignition switch ON and wait at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-271, "Diagnosis Procedure".
NO >> GO TO 3.
3.CHECK ENGINE COOLANT TEMPERATURE
WITH CONSULT-III
1. Select “COOLAN TEMP/S” in “DATA MONITOR” with CONSULT-III.
2. Check “COOLAN TEMP/S” value.
WITH GST
Follow the procedure “With CONSULT-III” above.
“
COOLAN TEMP/S” less than 60°C (140°F)?
YES >> INSPECTION END
NO >> GO TO 4.
4.PERFORM DTC CONFIRMATION PROCEDURE-II
WITH CONSULT-III
1. Cool engine down until “COOLAN TEMP/S” is less than 60 °C (140 °F).
2. Wait at least 10 seconds.
3. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Proceed to EC-271, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288290
1.CHECK DTC WITH COMBINATION METER
Refer to MWI-30, "
CONSULT-III Function".
Is the inspection result normal?
YES >> GO TO 2.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0181 FTT SENSOR
[Fuel tank temperature sensor
circuit range/performance] Rationally incorrect voltage from the sensor
is sent to ECM, compared with the voltage
signals from engine coolant temperature sen-
sor and intake air temperature sensor.  Harness or connectors
(The FTT sensor circuit is open or
shorted)
 Fuel tank temperature sensor
 Combination meter
Revision: 2010 May2011 QX56

EC-276
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0190, P0192,
P0193 FRP SENSOR
P0190, P0192, P0193 FRP SENSOR
DTC LogicINFOID:0000000006288295
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start the engine ON and wait at least 60 seconds.
2. Check DTC or 1st trip DTC.
Is DTC or 1st trip DTC detected?
YES >> Proceed to EC-276, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288296
1.CHECK FRP SENSOR POWER SUPPLY-I
1. Turn ignition switch OFF.
2. Disconnect FRP sensor connector.
3. Turn ignition switch ON.
4. Check the voltage between FRP sensor harness connector terminals.
Inspection result normal?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK FRP SENSOR POWER SUPPLY-II
Check the voltage between FRP sensor harness connector and the ground.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0190 Fuel rail pressure sensor
circuit low input and high in-
put Signal voltage from the fuel rail pressure
sensor remains at more than 4.84 V /
less than 0.2 V for 5 seconds or more.  Harness or connectors
(Fuel rail pressure sensor circuit is open or
shorted.)
(Power steering pressure sensor circuit is
open or shorted.)
(Low fuel pressure sensor circuit is open or
shorted.)
(The electrically-controlled cooling fan cou-
pling circuit is open or shorted)
 Fuel rail pressure sensor
 Power steering pressure sensor
 Low fuel pressure sensor
 Electrically-controlled cooling fan coupling
P0192
Fuel rail pressure sensor
circuit low input Signal voltage from the fuel rail pressure
sensor remains at less than 0.37 V for 5
seconds or more.
P0193 Fuel rail pressure sensor
circuit high input Signal voltage from the fuel rail pressure
sensor remains at more than 3.46 V for 5
seconds or more.
FRP sensor
Voltag e
(Approx.)
Connector +
−
terminal
F26 1 3 5 V
Revision: 2010 May2011 QX56

EC-278
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0190, P0192,
P0193 FRP SENSOR
6.CHECK FRP SENSOR SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between FRP sens or harness connector and ECM harness connector.
4. Also check harness for short to ground and to power.
Is inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
7.CHECK FRP SENSOR
Refer to EC-278, "
Component Inspection (Fuel Rail Pressure Sensor)".
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
Component Inspection (Fuel Rail Pressure Sensor)INFOID:0000000006288297
1.CHECK FRP SENSOR
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Select “DATA MONITOR” mode with CONSULT-III.
5. Check that the “FUEL PRES SEN V” indication.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Check FRP sensor signal voltage.
Is the inspection result normal?
YES >> INSPECTION END.
NO >> Replace FRP sensor. Refer to EM-48, "
Exploded View".
+−
Continuity
FRP sensor ECM
Connector Terminal Connector Terminal F26 2 F111 31 Existed
Monitor Item Condition Values/Status
FUEL PRES SEN V Engine speed: Idle 980 – 1,200 mV
Engine speed: Revving engine from idle to 4,000 rpm
quickly
1,100 – 2,900 mV
+
−
Condition Va l u e
(Approx.)
ECM
Connector Terminal Connector Terminal
F 111 3 1 F 111 4 0 [Engine is running]
 Warm-up condition
 Idle speed
0.98 – 1.2 V
[Engine is running]
 Warm-up condition
 Revving engine from idle to 4,000 rpm quickly 1.1 – 2.9 V
Revision: 2010 May2011 QX56

P0191 FRP SENSOREC-281
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Is inspection result normal?
YES >> Check intermittent incident. Refer to
GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
6.CHECK FRP SENSOR SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between FRP sens or harness connector and ECM harness connector.
4. Also check harness for short to ground and to power.
Is inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace error-detected parts.
7.CHECK FRP SENSOR
Refer to EC-278, "
Component Inspection (Fuel Rail Pressure Sensor)".
Is inspection result normal?
YES >> Check intermittent incident. Refer to GI-40, "Intermittent Incident".
NO >> Repair or replace error-detected parts.
Component Inspection (Fuel Rail Pressure Sensor)INFOID:0000000006288360
1.CHECK FRP SENSOR
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Select “DATA MONITOR” mode with CONSULT-III.
5. Check that the “FUEL PRES SEN V” indication.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect harness connector disconnected.
3. Start the engine.
4. Check FRP sensor signal voltage.
ECM Ground Continuity
Connector Terminal
F 111 5
Ground Existed
E80 11 4
11 5
174
175
+ −
Continuity
FRP sensor ECM
Connector Terminal Connector Terminal F26 2 F111 31 Existed
Monitor Item Condition Values/Status
FUEL PRES SEN V Engine speed: Idle 980 – 1,200 mV
Engine speed: Revving engine from idle to 4,000 rpm
quickly
1,100 – 2,900 mV
Revision: 2010 May2011 QX56

P0196 EOT SENSOREC-283
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0196 EOT SENSOR
DTC LogicINFOID:0000000006288301
DTC DETECTION LOGIC
NOTE:
If DTC P0196 is displayed with P0197 or P0198, fi
rst perform the trouble diagnosis for DTC P0197,
P0198. Refer to EC-285, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
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.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and let it idle for 5 minutes and 10 seconds.
6. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> EC-284, "Diagnosis Procedure".
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE-II
WITH CONSULT-III
1. Select “DATA MONITOR” mode with CONSULT-III.
2. Check that “COOLAN TEMP/S” indicates above 80 °C (176 °F).
If it is above 80 °C (176 °F), go to the following steps.
If it is below 80 °C (176 °F), warm engine up until “COOLAN TEMP/S” indicates more than 80 °C (176 °F).
Then perform the following steps.
3. Turn ignition switch OFF and soak the vehicle in a cool place.
4. Turn ignition switch ON.
NOTE:
Do not turn ignition switch OFF until step 8.
5. Select “DATA MONITOR” mode with CONSULT-III.
6. Check the following.
If they are within the specifi ed range, perform the following steps.
If they are out of the specified range, soak the vehicle to meet t he above conditions. Then perform the fol-
lowing steps.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0196 EOT SENSOR
(Engine oil temperature sen-
sor range/performance) Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signals
from engine coolant temperature sensor and in-
take air temperature sensor.  Harness or connectors
(The EOT sensor circuit is open or
shorted)
 Engine oil temperature sensor
COOLAN TEMP/S Below 40 °C (104 °F)
INT/A TEMP SE Below 40 °C (104 °F)
Difference between “COOLAN TEMP/S” and “INT/A TEMP SE” Within 6 °C (11 °F)
Revision: 2010 May2011 QX56