Nissan Altima L32. Manual - part 417

P0340 CMP SENSOR (PHASE)

EC-789

< COMPONENT DIAGNOSIS >

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1. Disconnect ECM harness connector.

2. Check the continuity between CMP sensor (PHASE) harness connector and ECM harness connector.

3. Also check harness for short to ground and short to power.
Is the inspection result normal?

YES

>> GO TO 6.

NO

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

6.

CHECK CAMSHAFT POSITION SENSOR (PHASE)

Refer to 

EC-789, "Component Inspection"

.

Is the inspection result normal?

YES

>> GO TO 7.

NO

>> Replace camshaft position sensor (PHASE).

7.

CHECK CAMSHAFT (INT)

Check the following.

• Accumulation of debris to the signal plate of camshaft (1) rear end

• Chipping signal plate of camshaft rear end
Is the inspection result normal?

YES

>> GO TO 8.

NO

>> Remove debris and clean the signal plate of camshaft

rear end or replace camshaft.

8.

CHECK INTERMITTENT INCIDENT

Refer to 

GI-42, "Intermittent Incident"

.

>> INSPECTION END

Component Inspection

INFOID:0000000004349756

1.

CHECK CAMSHAFT POSITION SENSOR (PHASE)-I

1. Turn ignition switch OFF.

2. Loosen the fixing bolt of the sensor.

3. Disconnect camshaft position sensor (PHASE) harness connector.

4. Remove the sensor.

5. Visually check the sensor for chipping.
Is the inspection result normal?

YES

>> GO TO 2.

NO

>> Replace camshaft position sensor (PHASE).

2.

CHECK CAMSHAFT POSITION SENSOR (PHASE)-II

CMP sensor (PHASE)

ECM

Continuity

Connector

Terminal

Connector Terminal

F55

3

F13

69

Existed

JMBIA0096ZZ

JMBIA0065ZZ

EC-790

< COMPONENT DIAGNOSIS >

[QR25DE EXCEPT FOR CALIFORNIA]

P0340 CMP SENSOR (PHASE)

Check resistance camshaft position sensor (PHASE) terminals as

follows.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Replace camshaft position sensor (PHASE).

Terminals (Polarity)

Resistance

1 (+) - 2 (-)

Except 0 or 

∞Ω [at 25°C (77°F)]

1 (+) - 3 (-)

2 (+) - 3 (-)

PBIA9584J

P0420 THREE WAY CATALYST FUNCTION

EC-791

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[QR25DE EXCEPT FOR CALIFORNIA]

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P0420 THREE WAY CATALYST FUNCTION

DTC Logic

INFOID:0000000004349757

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

1.

INSPECTION START

Do you have CONSULT-III?
Do you have CONSULT-III?

YES

>> GO TO 2.

NO

>> GO TO 7.

2.

PRECONDITIONING

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

least 10 seconds before conducting the next test.

TESTING CONDITION:

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

>> GO TO 3.

3.

PERFORM DTC CONFIRMATION PROCEDURE-I

 With CONSULT-III

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.

10. Check the indication of “CATALYST”.
Which is displayed on CONSULT-III screen?

SEF484YB

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P0420

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

EC-792

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P0420 THREE WAY CATALYST FUNCTION

CMPLT >> GO TO 6.

INCMP >> GO TO 4.

4.

PERFORM DTC CONFIRMATION PROCEDURE-II

1. Wait 5 seconds at idle.

2. 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).

Does the indication change to “CMPLT”?

YES

>> GO TO 6.

NO

>> GO TO 5.

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.

6.

PERFORM DTC CONFIRMATION PROCEDURE-III

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

YES

>> Go to 

EC-793, "Diagnosis Procedure"

.

NO

>> INSPECTION END

7.

PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to 

EC-792, "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

NO

>> Go to 

EC-793, "Diagnosis Procedure"

.

Component Function Check

INFOID:0000000004349758

1.

PERFORM COMPONENT FUNCTION CHECK

Without CONSULT-III

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 and ground

under the following condition.

Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-793, "Diagnosis Procedure"

.

ECM

Ground

Condition

Voltage

Con-

nector

Termi-

nal

F13

33

(HO2S

2 sig-

nal)

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

JMBIA1721ZZ