Nissan Frontier. Manual - part 423

P0340 CMP SENSOR (PHASE)

EC-263

< DTC/CIRCUIT DIAGNOSIS >

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 WITH GST

Follow the procedure “WITH CONSULT” above.

Diagnosis Procedure

INFOID:0000000009480924

1.

CHECK STARTING SYSTEM

Turn ignition switch to START position.

Yes or No

Yes

>> GO TO 2.

No

>> Check starting system. Refer to 

STR-6, "Work Flow (With GR8-1200 NI)"

 or 

STR-10, "Work Flow

(Without GR8-1200 NI)"

.

2.

CHECK GROUND CONNECTIONS

1. Turn ignition switch OFF.

2. Loosen and retighten two ground screws on the body. Refer to 

EC-149, "Ground Inspection"

.

OK or NG

OK

>> GO TO 3.

NG

>> Repair or replace ground connections.

3.

CHECK CAMSHAFT POSITION (CMP) SENSOR (PHASE) POWER SUPPLY CIRCUIT

1. Disconnect camshaft position (CMP) sensor (PHASE) harness

connector.

2. Turn ignition switch ON.

3. Check voltage between CMP sensor (PHASE) terminal 1 and

ground with CONSULT or tester.

OK or NG

OK

>> GO TO 5.

NG

>> GO TO 4.

Does the engine turn over?
Does the starter motor operate?

BBIA0614E

BBIA0615E

Voltage: Approximately 5 V

PBIB0664E

EC-264

< DTC/CIRCUIT DIAGNOSIS >

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P0340 CMP SENSOR (PHASE)

4.

DETECT MALFUNCTIONING PART

Check the following.

• Harness for open or short between camshaft position sensor (PHASE) and ECM

>> Repair open circuit, short to ground or short to power in harness or connectors.

5.

CHECK CMP SENSOR (PHASE) GROUND CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Check harness continuity between CMP sensor (PHASE) terminal 3 and ground.

3. Also check harness for short to power.
OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

6.

DETECT MALFUNCTIONING PART

Check the following.

• Harness for open or short between CMP sensor (PHASE) and ECM.

>> Repair open circuit or short to power in harness or connectors.

7.

CHECK CMP SENSOR (PHASE) INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Disconnect ECM harness connector.

2. Check harness continuity between ECM terminal 69 and CMP sensor (PHASE) terminal 2. 

Refer to Wiring Diagram.

3. Also check harness for short to ground and short to power.
OK or NG

OK

>> GO TO 8.

NG

>> Repair open circuit, short to ground or short to power in harness or connectors.

8.

CHECK CAMSHAFT POSITION SENSOR (PHASE)

Refer to 

EC-265, "Component Inspection"

.

OK or NG

OK

>> GO TO 9.

NG

>> Replace camshaft position sensor (PHASE). Refer to 

EM-45, "Exploded View"

.

9.

CHECK CAMSHAFT (INTAKE)

Check the following.

• Accumulation of debris to the signal plate of camshaft rear end

• Chipping signal plate of camshaft rear end
OK or NG

OK

>> GO TO 10.

NG

>> Remove debris and clean the signal plate of camshaft

rear end or replace camshaft. Refer to 

EM-54, "Removal

and Installation"

.

10.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

Continuity should exist.

Continuity should exist.

PBIB0565E

P0340 CMP SENSOR (PHASE)

EC-265

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>> INSPECTION END

Component Inspection

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CAMSHAFT POSITION SENSOR (PHASE)

1. Loosen the fixing bolt of the sensor.
2. Disconnect camshaft position sensor (PHASE) harness connector.
3. Remove the sensor.
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)]

1 (+) - 2 (-)

Except 0 or 

∞

1 (+) - 3 (-)

2 (+) - 3 (-)

PBIB0564E

EC-266

< DTC/CIRCUIT DIAGNOSIS >

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P0420 THREE WAY CATALYST FUNCTION

P0420 THREE WAY CATALYST FUNCTION

On Board Diagnosis Logic

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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 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

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NOTE:

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at

least 10 seconds before conducting the next test.

With CONSULT

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. 
2. Start engine and warm it up to 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.
9. Rev engine between 2,500 and 3,500 rpm and hold it for 3 consecutive minutes, then release the acceler-

ator pedal completely.

If “INCMP” of “CATALYST” changed to “CMPLT”, go to step 12.

10. Wait 5 seconds at idle.

11. 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).

If not “CMPLT”, stop engine and cool it down to less than 70

°C (158°F) and then retest step 1.

12. Select “SELF-DIAG RESULTS” mode with CONSULT.
13. Confirm that the 1st trip DTC is not detected.

If the 1st trip DTC is detected, go to 

EC-267, "Diagnosis Procedure"

.

PBIB2377E

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0420
0420

Catalyst system efficiency 
below threshold

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