Nissan Altima 2007-2012 Service Manual: P2A00 A/F Sensor 1

Description

The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sensor.

The sensor element of the A/F sensor 1 is composed an electrode layer, which transports ions. It has a heater in the element.

The sensor is capable of precise measurement = 1, but also in the lean and rich range. Together with its control electronics, the sensor outputs a clear, continuous signal throughout a wide range.

The exhaust gas components diffuse through the diffusion layer at the sensor cell. An electrode layer is applied voltage, and this current relative oxygen density in lean. Also this current relative hydrocarbon density in rich.

Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this electrode layer of current. In addition, a heater is integrated in the sensor to ensure the required operating temperature of about 800°C (1,472°F).

DTC Logic

DTC DETECTION LOGIC

To judge the malfunction, the A/F signal computed by ECM from the A/F sensor 1 signal is monitored not to be shifted to LEAN side or RICH side.

DTC CONFIRMATION PROCEDURE

1.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: Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

>> GO TO 2.

2.PERFORM DTC CONFIRMATION PROCEDURE

1. Clear the mixture ratio self-learning value. Refer to EC-568, "MIXTURE RATIO SELF-LEARNING VALUE CLEAR : Special Repair Requirement".

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 1 minute under no load.

4. Let engine idle for 1 minute.

5. Keep engine speed between 2,500 and 3,000 rpm for 20 minutes.

6. Check 1st trip DTC$.

Is 1st trip DTC detected? YES >> Go to EC-940, "Diagnosis Procedure".

NO >> INSPECTION END

Diagnosis Procedure

1.CHECK GROUND CONNECTION

1. Turn ignition switch OFF.

2. Check ground connection E9. Refer to Ground Inspection in GI-45, "Circuit Inspection".

Is the inspection result normal? YES >> GO TO 2.

NO >> Repair or replace ground connection.

2.RETIGHTEN A/F SENSOR 1

1. Loosen and retighten the A/F sensor 1. Refer to EM-30, "Removal and Installation".

>> GO TO 3.

3.CHECK FOR INTAKE AIR LEAK

1. Start engine and run it at idle.

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

Is intake air leak detected? YES >> GO TO 4.

NO >> Repair or replace.

4.CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

1. Clear the mixture ratio self-learning value. Refer to EC-568, "MIXTURE RATIO SELF-LEARNING VALUE CLEAR : Special Repair Requirement".

2. Run engine for at least 10 minutes at idle speed.

Is the 1st trip DTC P0171 or P0172 detected? Is it difficult to start engine? YES >> Perform trouble diagnosis for DTC P0171or P0172. Refer to EC-759, "DTC Logic" or EC-763, "DTC Logic".

NO >> GO TO 5.

5.CHECK HARNESS CONNECTOR

1. Turn ignition switch OFF.

2. Disconnect A/F sensor 1 harness connector.

3. Check harness connector for water.

Water should not exit.

Is the inspection result normal? YES >> GO TO 6.

NO >> Repair or replace harness connector.

6.CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT

1. Turn ignition switch ON.

2. Check the voltage between A/F sensor 1 harness connector and ground.

Is the inspection result normal? YES >> GO TO 8.

NO >> GO TO 7.

7.DETECT MALFUNCTIONING PART

Check the following.

• IPDM E/R harness connector F10

• 15A fuse (No. 37) • Harness for open or short between A/F sensor 1 and fuse

>> Repair or replace harness or connectors.

8.CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.

4. Check the continuity between ECM harness connector or A/F sensor 1 harness connector and ground.

5. Also check harness for short to power.

Is the inspection result normal? YES >> GO TO 9.

NO >> Repair open circuit or short to ground or short to power in harness or connectors.

9.CHECK A/F SENSOR 1 HEATER

Refer to EC-686, "Component Inspection".

Is the inspection result normal? YES >> GO TO 10.

NO >> GO TO 11.

10.CHECK INTERMITTENT INCIDENT

Perform GI-42, "Intermittent Incident".

Is the inspection result normal? YES >> GO TO 11.

NO >> Repair or replace.

11.REPLACE AIR FUEL RATIO (A/F) SENSOR 1

Replace air fuel ratio (A/F) sensor 1.

CAUTION: • Discard any sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.

• Before installing new sensor, clean exhaust system threads using oxygen sensor thread cleaner tool [commercial service tool: (J-43897-18) or (J-43897-12)] and approved anti-seize lubricant (commercial service tool).

Do you have CONSULT-III? YES >> GO TO 12.

NO >> GO TO 13.

12.CONFIRM A/F ADJUSTMENT DATA

1. Turn ignition switch ON.

2. Select “A/F ADJ-B1” in “DATA MONITOR” mode with CONSULT-III.

3. Make sure that “0.000” is displayed on CONSULT-III screen.

Is “0.000” displayed? YES >> INSPECTION END

NO >> GO TO 13.

13.CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

Clear the mixture ratio self-learning value. Refer to EC-568, "MIXTURE RATIO SELF-LEARNING VALUE CLEAR : Special Repair Requirement".

Do you have CONSULT-III? YES >> GO TO 14.

NO >> INSPECTION END

14.CONFIRM A/F ADJUSTMENT DATA

1. Turn ignition switch ON.

2. Select “A/F ADJ-B1” in “DATA MONITOR” mode with CONSULT-III.

3. Make sure that “0.000” is displayed on CONSULT-III screen.

>> INSPECTION END

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