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Nissan Maxima. Manual - part 455

EC-304

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0420, P0430 THREE WAY CATALYST FUNCTION

P0420, P0430 THREE WAY CATALYST FUNCTION

DTC Logic

INFOID:0000000010094998

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 decreases, 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

INSPECTION START

Will CONSULT be used?
Will CONSULT be used?

YES

>> GO TO 2.

>> GO TO 7.

PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-

ing the next test.

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:

Do not maintain engine speed for more than the specified minutes below.

>> GO TO 3.

PERFORM DTC CONFIRMATION PROCEDURE-I

With CONSULT

1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT.

2. Start engine and warm it up to the normal operating temperature.

3. Turn ignition switch OFF and wait at least 10 seconds.

4. Turn ignition switch ON.

5. Turn ignition switch OFF and wait at least 10 seconds.

6. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.

7. Let engine idle for 1 minute.

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.

PBIB2055E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0420

Catalyst system efficien-
cy below threshold
(bank 1)

• Three way catalyst (manifold) does not oper-

ate 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

Catalyst system efficien-
cy below threshold
(bank 2)

P0420, P0430 THREE WAY CATALYST FUNCTION

EC-305

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

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 screen?

CMPLT >> GO TO 6.

INCMP >> GO TO 4.

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 6.

>> GO TO 5.

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 3.

PERFORM DTC CONFIRMATION PROCEDURE-III

Check 1st trip DTC.
Is 1st trip DTC detected?

YES

>> Go to

EC-306, "Diagnosis Procedure"

>> INSPECTION END

PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to

EC-305, "Component Function Check"

NOTE:

Use component function check to check the overall function 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

>> Go to

EC-306, "Diagnosis Procedure"

Component Function Check

INFOID:0000000010094999

Regarding Wiring Diagram information, refer to

EC-554, "Wiring Diagram"

PERFORM COMPONENT FUNCTION CHECK

Without CONSULT

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. Open engine hood.

EC-306

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

P0420, P0430 THREE WAY CATALYST FUNCTION

8. Check the voltage between ECM harness connector terminals

under the following conditions.

Is the inspection result normal?

YES

>> INSPECTION END

>> Go to

EC-306, "Diagnosis Procedure"

Diagnosis Procedure

INFOID:0000000010095000

Regarding Wiring Diagram information, refer to

EC-554, "Wiring Diagram"

CHECK EXHAUST SYSTEM

Visually check exhaust tubes and muffler for dents.
Is the inspection result normal?

YES

>> GO TO 2.

>> Repair or replace malfunctioning part.

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.

>> GO TO 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.

JMBIA1865ZZ

DTC

ECM

Condition

Voltage (V)

Connec-

tor

–

Terminal

P0420

F13

[HO2S2 (bank 1)

signal]

(Sensor
ground)

Keeping 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

[HO2S2 (bank 2)

signal]

PBIB1216E

P0420, P0430 THREE WAY CATALYST FUNCTION

EC-307

< DTC/CIRCUIT DIAGNOSIS >

[VQ35DE]

>> GO TO 4.

CHECK IGNITION TIMING

Check idle speed and ignition timing.

For procedure, refer to

EC-14, "BASIC INSPECTION : Special Repair Requirement"

For specification, refer to

EC-596, "Ignition Timing"

Is the inspection result normal?

YES

>> GO TO 5.

>> Follow the

EC-14, "BASIC INSPECTION : Special Repair Requirement"

CHECK FUEL INJECTORS

1. Stop engine and then turn ignition switch ON.

2. Check the voltage between ECM harness connectors.

Is the inspection result normal?

YES

>> GO TO 6.

>> Perform

EC-496, "Diagnosis Procedure"

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:

Do not use CONSULT to release fuel pressure, or fuel pressure applies again during the following proce-

dure.

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 electrical discharge from the ignition coils. Refer

EM-42, "Removal and Installation (LH)"

EM-42, "Removal and Installation (RH)"

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 about 3 seconds, and check whether spark is

generated between the spark plug and the grounded metal por-

tion.

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, because the electrical discharge

voltage becomes 20 kV or more.

ECM

Ground

Voltage

–

Connector

Terminal

Connector

Terminal

F14

E10

112

Battery voltage

JMBIA1869GB

Spark should be generated.

JMBIA0066GB

Content .. 453 454 455 456 ..