Infiniti QX56 (JA60). Manual - part 389

 

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Infiniti QX56 (JA60). Manual - part 389

 

 

EC-208

< COMPONENT DIAGNOSIS >

[VK56DE]

P0340 CMP SENSOR (PHASE)

4. Visually check the sensor for chipping.

5. Check resistance as shown in the figure.

PBIB0563E

Terminal No. (Polarity)

Resistance 

Ω [at 25°C (77°F)]

3(+) - 1 (-)

Except 0 or 

2 (+) - 1 (-)

3 (+) - 2 (-)

PBIB0564E

P0420, P0430 THREE WAY CATALYST FUNCTION

EC-209

< COMPONENT DIAGNOSIS >

[VK56DE]

C

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EC

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P0420, P0430 THREE WAY CATALYST FUNCTION

On Board Diagnosis Logic

INFOID:0000000005149229

The ECM monitors the switching frequency ratio of air fuel sensor

(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 air fuel ratio (A/F) sensor 1 and heated

oxygen sensor 2 approaches a specified limit value, the three way

catalyst (manifold) malfunction is diagnosed.

DTC Confirmation Procedure

INFOID:0000000005149230

NOTE:

If DTC Confirmation Procedure has been previously conducted, always perform the following procedure

before conducting the next step.
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.

 WITH CONSULT-III

TESTING CONDITION:

Do not hold engine speed for more than the specified minutes below.
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure 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).

7. Open engine hood.
8. Select “DTC & SRT CONFIRMATION” then “SRT WORK SUPPORT” mode with CONSULT-III.
9. Rev engine up to 2,000 to 3,000 rpm and hold it for 3 consecutive 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-III.

PBIB2055E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0420
0420
(Bank 1)

Catalyst system efficien-
cy below threshold

• 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 leaks
• Fuel injector
• Fuel injector leaks
• Spark plug
• Improper ignition timing

P0430
0430
(Bank 2)

EC-210

< COMPONENT DIAGNOSIS >

[VK56DE]

P0420, P0430 THREE WAY CATALYST FUNCTION

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

If the 1st trip DTC is detected, go to 

EC-210, "Diagnosis Procedure"

.

Overall Function Check

INFOID:0000000005149231

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 probes between ECM terminals ECM terminals 55

[HO2S2 (bank 1) signal], 74 [HO2S2 (bank 2) 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-210, "Diagnosis Procedure"

.

• 1 cycle: 0.6 - 1.0 

→ 0 - 0.3 → 0.6 - 1.0

Diagnosis Procedure

INFOID:0000000005149232

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 (manifold).

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

PBIB2056E

PBIB1216E

P0420, P0430 THREE WAY CATALYST FUNCTION

EC-211

< COMPONENT DIAGNOSIS >

[VK56DE]

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Check the following items. Refer to 

EC-13, "Basic Inspection"

.

OK or NG

OK

>> GO TO 5.

NG

>> Follow the 

EC-13, "Basic Inspection"

.

5.

CHECK FUEL INJECTOR

1. Stop engine and then turn ignition switch ON.

2. Check voltage between ECM terminals 21, 22, 23, 40, 41, 42,

44, 63 and ground with CONSULT-III or tester.

Refer to Wiring Diagram for fuel injector, 

EC-435, "Wiring Dia-

gram - ENGINE CONTROL SYSTEM -"

.

OK or NG

OK

>> GO TO 6.

NG

>> Perform 

EC-407, "Diagnosis 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 in IPDM E/R to release fuel pressure.

NOTE:

Do not use CONSULT-III 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 (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:

• During the operation, always stay 0.5 m (1.6 ft) or more

away from the spark plug and the ignition coil. Be careful

not to get an electrical shock while checking, because the

electrical discharge voltage becomes 20 kV or more.

• It might cause to damage the ignition coil if the gap of more than 17 mm (0.66 in) is taken.

NOTE:

When the gap is less than 13 mm (0.52 in), a spark might be generated even if the coil is malfunc-

tioning.

Items

Specifications

Target idle speed

650 

± 50 rpm (in P or N position)

Ignition timing

15 

± 5° BTDC (in P or N position)

Battery voltage should exist.

PBIB1527E

Spark should be generated.

BBIA0380E

PBIB2325E

 

 

 

 

 

 

 

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