Infiniti M35/M45 Y50. Manual - part 477

DTC P0420, P0430 THREE WAY CATALYST FUNCTION

EC-381

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8.

Select “DTC & SRT CONFIRMATION” then “SRT WORK SUP-
PORT” mode with CONSULT-II.

9.

Rev engine up to 2,000 to 3,000 rpm and hold it for 3 consecu-
tive minutes then release the accelerator pedal completely.
If “INCMP” of “CATALYST” changed to “CMPLT”, go to step 12.

10. Wait 5 seconds at idle.

11. Rev engine up to 2,000 to 3,000 rpm and maintain it until

“INCMP” of “CATALYST” changes to “CMPLT” (It will take
approximately 5 minutes).
If not “CMPLT”, stop engine and cool it down to less than 70

°

C

(158

°

F) and then retest from step 1.

12. Select “SELF-DIAG RESULTS” mode with CONSULT-II.

13. Confirm that the 1st trip DTC is not detected.

If the 1st trip DTC is detected, go to 

EC-382, "Diagnostic Proce-

dure"

 .

Overall Function Check

NBS004ZE

Use this procedure to check the overall function of the three way catalyst (manifold). During this check, a 1st
trip DTC might not be confirmed.

 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.

Set voltmeter probe between ECM terminals ECM terminals 55
[HO2S2 (bank 2) signal], 74 [HO2S2 (bank 1) signal] and
ground.

7.

Keep engine speed at 2,500 rpm constant under no load.

8.

Make sure that the voltage does not vary for more than 5 sec-
onds.
If the voltage fluctuation cycle takes less than 5 seconds, go to

EC-382, "Diagnostic Procedure"

 .

●

1 cycle: 0.6 - 1.0 

→

 0 - 0.3 

→

 0.6 - 1.0

PBIB1784E

PBIB1785E

SEF535Z

PBIB1108E

EC-382

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DTC P0420, P0430 THREE WAY CATALYST FUNCTION

Diagnostic Procedure

NBS004ZF

1. 

CHECK EXHAUST SYSTEM

Visually check exhaust tubes and muffler for dent.
OK or NG

OK

>> GO TO 2.

NG

>> Repair or replace.

2. 

CHECK EXHAUST GAS LEAK

1.

Start engine and run it at idle.

2.

Listen for an exhaust gas leak before the three way catalyst 1.

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace.

3. 

CHECK INTAKE AIR LEAK

Listen for an intake air leak after the mass air flow sensor.

OK or NG

OK

>> GO TO 4.

NG

>> Repair or replace.

4. 

CHECK IGNITION TIMING

Check the following items. Refer to 

EC-78, "Basic Inspection"

 .

OK or NG

OK

>> GO TO 5.

NG

>> Follow the 

EC-78, "Basic Inspection"

 .

PBIB1922E

Items

Specifications

Target idle speed

650 

±

 50 rpm (in P or N position)

Ignition timing

15 

±

 5

°

 BTDC (in P or N position)

DTC P0420, P0430 THREE WAY CATALYST FUNCTION

EC-383

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5. 

CHECK FUEL INJECTORS

1.

Stop engine and then turn ignition switch ON.

2.

Check voltage between ECM terminals 21, 22, 23, 40, 41, 42
and ground with CONSULT-II or tester.
Refer to Wiring Diagram for fuel Injectors, 

EC-670, "Wiring Dia-

gram"

 .

OK or NG

OK

>> GO TO 6.

NG

>> Perform 

EC-671, "Diagnostic Procedure"

 .

6. 

CHECK FUNCTION OF IGNITION COIL-I

CAUTION:

Do the following procedure in the place where ventilation is good without the combustible.

1.

Turn ignition switch OFF.

2.

Remove fuel pump fuse (1) in IPDM E/R (2) to release fuel pres-
sure.

NOTE:
Do not use CONSULT-II to release fuel pressure, or fuel pres-
sure applies again during the following procedure.

3.

Start engine.

4.

After engine stalls, crank it two or three times to release all fuel
pressure.

5.

Turn ignition switch OFF.

6.

Remove all ignition coil harness connectors to avoid the electri-
cal 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

between the edge of the spark plug and grounded metal portion
as shown in the figure.

11. Crank engine for about 3 seconds, and check whether spark is

generated between the spark plug and the grounded metal por-
tion.

CAUTION:

●

Do not approach to the spark plug and the ignition coil
within 50cm. Be careful not to get an electrical shock
while checking, because the electrical discharge voltage
becomes 20kV or more.

●

It might cause to damage the ignition coil if the gap of more than 17 mm is taken.

NOTE:
When the gap is less than 13 mm, the spark might be generated even if the coil is malfunctioning.

OK or NG

OK

>> GO TO 10.

NG

>> GO TO 7.

Voltage: Battery voltage

PBIB1172E

Spark should be generated.

PBIB2697E

PBIB2325E

EC-384

[VQ35DE]

DTC P0420, P0430 THREE WAY CATALYST FUNCTION

7. 

CHECK FUNCTION OF IGNITION COIL-II

1.

Turn ignition switch OFF.

2.

Disconnect spark plug and connect a known-good spark plug.

3.

Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded metal portion.

OK or NG

OK

>> GO TO 8.

NG

>> Check ignition coil, power transistor and their circuits. Refer to 

EC-691, "IGNITION SIGNAL"

 .

8. 

CHECK SPARK PLUG

Check the initial spark plug for fouling, etc.

OK or NG

OK

>> Replace spark plug(s) with standard type one(s). For

spark plug type, refer to 

MA-20, "Changing Spark Plugs

(Platinum-Tipped Type)"

 .

NG

>> 1. Repair or clean spark plug.

2. GO TO 9.

9. 

CHECK FUNCTION OF IGNITION COIL-III

1.

Reconnect the initial spark plugs.

2.

Crank engine for about 3 seconds, and recheck whether spark is generated between the spark plug and
the grounded portion.

OK or NG

OK

>> INSPECTION END

NG

>> Replace spark plug(s) with standard type one(s). For spark plug type, refer to 

MA-20, "Changing

Spark Plugs (Platinum-Tipped Type)"

 .

10. 

CHECK FUEL INJECTOR

1.

Turn ignition switch OFF.

2.

Remove fuel injector assembly.
Refer to 

EM-47, "FUEL INJECTOR AND FUEL TUBE"

 .

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.
Make sure fuel does not drip from fuel injector.

OK or NG

OK (Does not drip.)>>GO TO 11.
NG (Drips.)>>Replace the fuel injector(s) from which fuel is dripping.

Spark should be generated.

SEF156I

Spark should be generated.