Page 2329 of 5598
![INFINITI QX56 2011 Factory Service Manual
P0340, P0345 CMP SENSOREC-305
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
NO >> Repair short to ground or short to power in harness or connectors.
5.CHECK COMPONENTS
Check the INFINITI QX56 2011 Factory Service Manual
P0340, P0345 CMP SENSOREC-305
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
NO >> Repair short to ground or short to power in harness or connectors.
5.CHECK COMPONENTS
Check the](/manual-img/42/57033/w960_57033-2328.png)
P0340, P0345 CMP SENSOREC-305
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
NO >> Repair short to ground or short to power in harness or connectors.
5.CHECK COMPONENTS
Check the following.
Battery current sensor (Refer to EC-414, "
Component Inspection (Battery Current Sensor)".)
Crankshaft position sensor (Refer to EC-301, "
Component Inspection (Crankshaft Position Sensor)".)
Refrigerant pressure sensor (Refer to EC-520, "
Component Function Check".)
EVAP control system pressure sensor (Refer to EC-335, "
Component Inspection (EVAP Control System
Pressure Sensor)".)
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace malfunctioning component.
6.CHECK APP SENSOR
Refer to EC-470, "
Component Inspection (Accelerator Pedal Position Sensor)".
Is the inspection result normal?
YES >> GO TO 12.
NO >> GO TO 7.
7.REPLACE ACCELERATOR PEDAL ASSEMBLY
Replace accelerator pedal assembly. Refer to ACC-3, "
MODELS WITHOUT DISTANCE CONTROL ASSIST
SYSTEM : Removal and Installation" (Without distance control assist system) or ACC-4, "MODELS WITH
DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation" (With distance control assist system).
>> INSPECTION END
8.CHECK CMP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between CMP sens or harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 9.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
9.CHECK CMP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between CMP sens or harness connector and ECM harness connector.
2. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 10.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
10.CHECK CAMSHAFT POSITION SENSOR
Refer to EC-306, "
Component Inspection (Camshaft Position Sensor)".
Is the inspection result normal?
DTC CMP sensor ECM
Continuity
Bank Connector Terminal Connector Terminal
P0340 1 F84 2 F11068
Existed
P0345 2 F83 2 99
DTC CMP sensor ECM
Continuity
Bank Connector Terminal Connector Terminal
P0340 1 F84 3 F11095
Existed
P0345 2 F83 3 73
Revision: 2010 May2011 QX56
Page 2330 of 5598
![INFINITI QX56 2011 Factory Service Manual
EC-306
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0340, P0345 CMP SENSOR
YES >> GO TO 11
NO >> Replace malfunctioning camshaft position sensor. Refer to
EM-61, "
Exploded View".
11 .CHECK CAMSHAFT (INT)
Che INFINITI QX56 2011 Factory Service Manual
EC-306
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0340, P0345 CMP SENSOR
YES >> GO TO 11
NO >> Replace malfunctioning camshaft position sensor. Refer to
EM-61, "
Exploded View".
11 .CHECK CAMSHAFT (INT)
Che](/manual-img/42/57033/w960_57033-2329.png)
EC-306
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0340, P0345 CMP SENSOR
YES >> GO TO 11
NO >> Replace malfunctioning camshaft position sensor. Refer to
EM-61, "
Exploded View".
11 .CHECK CAMSHAFT (INT)
Check the following.
Accumulation of debris to the signal plate of camshaft front end
Chipping signal plate of camshaft front end
Is the inspection result normal?
YES >> GO TO 12.
NO >> Remove debris and clean the signal plate of camshaft
front end or replace camshaft.
12.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (Cam shaft Position Sensor)INFOID:0000000006217850
1.CHECK CAMSHAFT POSITION SENSOR-I
1. Turn ignition switch OFF.
2. Loosen the fixing bolt of the sensor.
3. Disconnect camshaft position sensor harness connector.
4. Remove the sensor.
5. Visually check the sensor for chipping.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace malfunctioning camshaft position sensor.
2.CHECK CAMSHAFT PO SITION SENSOR-II
Check resistance camshaft position sensor terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace malfunctioning camshaft position sensor. Refer to EM-61, "
Exploded View".
JMBIA0962ZZ
JMBIA0065ZZ
Terminals (Polarity) Resistance
1 (+) - 2 (-) Except 0 or ∞ Ω [at 25 °C (77 °F)]
1 (+) - 3 (-)
2 (+) - 3 (-)
Revision: 2010 May2011 QX56
Page 2331 of 5598
![INFINITI QX56 2011 Factory Service Manual
P0420, P0430 THREE WAY CATALYST FUNCTIONEC-307
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0420, P0430 THREE WAY CATALYST FUNCTION
DTC LogicINFOID:0000000006217851
DTC DETECTI INFINITI QX56 2011 Factory Service Manual
P0420, P0430 THREE WAY CATALYST FUNCTIONEC-307
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0420, P0430 THREE WAY CATALYST FUNCTION
DTC LogicINFOID:0000000006217851
DTC DETECTI](/manual-img/42/57033/w960_57033-2330.png)
P0420, P0430 THREE WAY CATALYST FUNCTIONEC-307
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0420, P0430 THREE WAY CATALYST FUNCTION
DTC LogicINFOID:0000000006217851
DTC DETECTION LOGIC
The ECM monitors the switching frequency ratio of air fuel ratio (A/F)
sensor 1 and heated oxygen sensor 2.
A three way catalyst (manifold) with high oxygen storage capacity
will indicate a low switching frequency of heated oxygen sensor 2.
As oxygen storage capacity decr
eases, the heated oxygen sensor 2
switching frequency will increase.
When the frequency ratio of A/F sensor 1 and heated oxygen sensor
2 approaches a specified limit value, the three way catalyst (mani-
fold) malfunction is diagnosed.
DTC CONFIRMATION PROCEDURE
1.INSPECTION START
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.
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 6.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
WITH CONSULT-III
TESTING CONDITION:
Do not maintain engine speed for mo re than the specified minutes below.
1. Start engine and warm it up to the 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 keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6. Let engine idle for 1 minute.
7. Select “DATA MONITOR” mode with CONSULT-III.
8. Check that “COOLAN TEMP/S” indicates more than 70 °C (158 °F).
If not, warm up engine and go to next step when “COOLAN TEMP/S” indication reaches to 70°C (158 °F).
9. Open engine hood.
10. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUPPORT” mode with CONSULT-III.
11. Rev engine between 2,000 and 3,000 rpm and hold it for 3 consecutive minutes then release the acceler-
ator pedal completely.
12. Check the indication of “CATALYST”.
Which is displayed on CONSULT-III screen?
CMPLT >> GO TO 5.
INCMP >> GO TO 3.
PBIB2055E
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0420 TW CATALYST SYS-B1
[Catalyst system efficiency
below threshold (bank 1)]
Three way catalyst (manifold) does not
operate properly.
Three way catalyst (manifold) does not have enough oxygen storage capacity. Three way catalyst (manifold)
Exhaust tube
Intake air leakage
Fuel injector
Fuel injector leakage
Spark plug
Improper ignition timing
P0430
TW CATALYST SYS-B2
[Catalyst system efficiency
below threshold (bank 2)]
Revision: 2010 May2011 QX56
Page 2332 of 5598
![INFINITI QX56 2011 Factory Service Manual
EC-308
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0420, P0430 THREE
WAY CATALYST FUNCTION
3.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Wait 5 seconds at idle.
2. Rev engine between 2,000 and 3,000 rpm and mai INFINITI QX56 2011 Factory Service Manual
EC-308
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0420, P0430 THREE
WAY CATALYST FUNCTION
3.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Wait 5 seconds at idle.
2. Rev engine between 2,000 and 3,000 rpm and mai](/manual-img/42/57033/w960_57033-2331.png)
EC-308
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0420, P0430 THREE
WAY CATALYST FUNCTION
3.PERFORM DTC CONFIRMATION PROCEDURE-II
1. Wait 5 seconds at idle.
2. Rev engine between 2,000 and 3,000 rpm and maintain it until “INCMP” of “CATALYST” changes to “CMPLT” (It will take approximately 5 minutes).
Does the indication change to
“CMPLT”?
YES >> GO TO 5.
NO >> GO TO 4.
4.PERFORM DTC CONFIRMATION PROCEDURE AGAIN
1. Stop engine and cool it down to less than 70 °C (158 °F).
2. Perform DTC CONFIRMATION PROCEDURE again.
>> GO TO 2.
5.PERFORM DTC CONFIRMATION PROCEDURE-III
Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-309, "Diagnosis Procedure".
NO >> INSPECTION END
6.PERFORM COMPONENT FUNCTION CHECK
WITH GST
Perform component function check. Refer to EC-308, "
Component Function Check".
NOTE:
Use component function check to check the overall functi on of the three way catalyst (manifold). During this
check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-309, "
Diagnosis Procedure"
Component Function CheckINFOID:0000000006217852
1.PERFORM COMPONENT FUNCTION CHECK
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle for 1 minute.
5. Open engine hood.
6. Check the voltage between ECM harness connector terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-309, "
Diagnosis Procedure".
DTC ECM
Condition Voltage
Connector +–
Terminal Terminal
P0420 F110 96
[HO2S2
(bank 1)] 100Keeping engine speed at 2,500 rpm
constant under no load The voltage fluctuation cycle takes more
than 5 seconds.
1 cycle: 0.6 - 1.0
→ 0 - 0.3 → 0.6 - 1.0
P0430 87
[HO2S2
(bank 2)]
Revision: 2010 May2011 QX56
Page 2333 of 5598
![INFINITI QX56 2011 Factory Service Manual
P0420, P0430 THREE WAY CATALYST FUNCTIONEC-309
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Diagnosis ProcedureINFOID:0000000006217853
1.CHECK EXHAUST SYSTEM
Visually check exha INFINITI QX56 2011 Factory Service Manual
P0420, P0430 THREE WAY CATALYST FUNCTIONEC-309
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Diagnosis ProcedureINFOID:0000000006217853
1.CHECK EXHAUST SYSTEM
Visually check exha](/manual-img/42/57033/w960_57033-2332.png)
P0420, P0430 THREE WAY CATALYST FUNCTIONEC-309
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Diagnosis ProcedureINFOID:0000000006217853
1.CHECK EXHAUST SYSTEM
Visually check exhaust tubes and muffler for dents.
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace malfunctioning part.
2.CHECK EXHAUST GAS LEAKAGE
1. Start engine and run it at idle.
2. Listen for an exhaust gas leakage before the three way catalyst (manifold).
Is exhaust gas leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 3.
3.CHECK INTAKE AIR LEAKAGE
Listen for an intake air leakage after the mass air flow sensor.
Is intake air leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 4.
4.CHECK IDLE SPEED AND IGNITION TIMING
Check idle speed and ignition timing.
For procedure, refer to EC-530, "
Inspection" and EC-531, "Inspection".
For specification, refer to EC-538, "
Idle Speed" and EC-538, "Ignition Timing".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Follow the EC-139, "
Work Procedure".
5.CHECK FUEL INJECTORS
Refer to EC-498, "
Component Function Check".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Perform EC-498, "
Diagnosis Procedure".
6.CHECK FUNCTION OF IGNITION COIL-I
CAUTION:
Perform the following procedure in a place with no combustible objects and good ventilation.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse in IPDM E/R to release fuel pressure.
NOTE:
For the fuse number, refer to EC-114, "
Wiring Diagram".
For the fuse arrangement, refer to PG-140, "
Fuse, Connector and Terminal Arrangement".
Do not use CONSULT-III to release fuel pressure, or fuel pressure applies again during the following
procedure.
3. Start engine.
4. After engine stalls, crank it 2 or 3 times to release all fuel pressure.
5. Turn ignition switch OFF.
PBIB1216E
Revision: 2010 May2011 QX56
Page 2334 of 5598
![INFINITI QX56 2011 Factory Service Manual
EC-310
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0420, P0430 THREE
WAY CATALYST FUNCTION
6. Remove all ignition coil harness connectors to avoi d the electrical discharge from the ignition coils.
7. Remove INFINITI QX56 2011 Factory Service Manual
EC-310
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0420, P0430 THREE
WAY CATALYST FUNCTION
6. Remove all ignition coil harness connectors to avoi d the electrical discharge from the ignition coils.
7. Remove](/manual-img/42/57033/w960_57033-2333.png)
EC-310
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0420, P0430 THREE
WAY CATALYST FUNCTION
6. Remove all ignition coil harness connectors to avoi d the electrical discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 - 0.66 in) between the edge of the spark plug and grounded metal
portion as shown in the figure.
11. Crank engine for approximately 3 seconds, and check whether spark is generated between the spark plug and the grounded
metal portion.
CAUTION:
Never place the spark plug and the ignition coil within 50
cm (19.7 in) each other. Be careful not to get an electrical
shock while checking, becau se the electrical discharge
voltage becomes 20 kV or more.
It might damage the ignition coil if the gap of more than 17 mm (0.66 in) is made.
NOTE:
When the gap is less than 13 mm (0.52 in), a spark might be generated even if the coil is malfunc-
tioning.
Is the inspection result normal?
YES >> GO TO 10.
NO >> GO TO 7.
7.CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a non-malfunctioning spark plug.
3. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded metal portion.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Check ignition coil, power transistor and their circuits. Refer to EC-506, "
Diagnosis Procedure".
8.CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.
Is the inspection result normal?
YES >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to EM-132, "
Spark Plug".
NO >> Repair or clean spark plug. Then GO TO 9.
9.CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for approximately 3 seconds, and rec heck whether spark is generated between the spark
plug and the grounded portion.
Is the inspection result normal?
YES >> INSPECTION END Spark should be generated.
JMBIA0066GB
Spark should be generated.
SEF156I
Spark should be generated.
Revision: 2010 May2011 QX56
Page 2335 of 5598
P0420, P0430 THREE WAY CATALYST FUNCTIONEC-311
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
NO >> Replace spark plug(s) with standard type one(s). For spark plug type, refer to
EM-132, "Spar k
Plug".
10.CHECK FUEL INJECTOR
1. Turn ignition switch OFF.
2. Remove fuel injector assembly. Refer to EM-49, "
Removal and Installation".
Keep fuel hose and all fuel injectors connected to fuel tube.
3. Disconnect all ignition coil harness connectors.
4. Reconnect all fuel injector harness connectors disconnected.
5. Turn ignition switch ON.
6. Check that fuel does not drip from fuel injector.
Does fuel drip from fuel injector?
YES >> Replace the fuel injector(s) from which fuel is dripping.
NO >> GO TO 11.
11 .CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> Replace three way catalyst assembly.
NO >> Repair or replace harness or connector.
Revision: 2010 May2011 QX56
Page 2336 of 5598
![INFINITI QX56 2011 Factory Service Manual
EC-312
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0441 EVAP CONTROL SYSTEM
P0441 EVAP CONTROL SYSTEM
DTC LogicINFOID:0000000006288304
DTC DETECTION LOGIC
NOTE:
If DTC P0441 is displayed with other DTC such
INFINITI QX56 2011 Factory Service Manual
EC-312
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0441 EVAP CONTROL SYSTEM
P0441 EVAP CONTROL SYSTEM
DTC LogicINFOID:0000000006288304
DTC DETECTION LOGIC
NOTE:
If DTC P0441 is displayed with other DTC such](/manual-img/42/57033/w960_57033-2335.png)
EC-312
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0441 EVAP CONTROL SYSTEM
P0441 EVAP CONTROL SYSTEM
DTC LogicINFOID:0000000006288304
DTC DETECTION LOGIC
NOTE:
If DTC P0441 is displayed with other DTC such
as P2122, P2123, P2127, P2128 or P2138, first perform
trouble diagnosis for other DTC.
In this evaporative emission (EVAP) control system, purge flow occurs during non-closed throttle conditions.
Purge volume is related to air intake volume. Under normal purge conditions (non-closed throttle), the EVAP
canister purge volume control solenoid valve is open to admit purge flow. Purge flow exposes the EVAP con-
trol system pressure sensor to intake manifold vacuum.
Under normal conditions (non-closed throttle), sensor output voltage indicates if pressure drop and purge flow
are adequate. If not, a ma lfunction is determined.
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.
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 5.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
PBIB1026E
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0441 EVAP PURG FLOW/MON
(EVAP control system incor-
rect purge flow) EVAP control system does not operate
properly, EVAP control system has a leak
between intake manifold and EVAP control
system pressure sensor. EVAP canister purge volume control sole-
noid valve stuck closed
EVAP control system pressure sensor and the circuit
Loose, disconnected or improper connection of rubber tube
Blocked rubber tube
Cracked EVAP canister
EVAP canister purge volume control sole- noid valve circuit
Accelerator pedal position sensor
Blocked purge port
EVAP canister vent control valve
Revision: 2010 May2011 QX56