Nissan Altima (L32) 2007-2012 Service Manual: P0043, P0044 HO2S3 heater

Description

SYSTEM DESCRIPTION

The ECM performs ON/OFF control of the heated oxygen sensor 3 heater corresponding to the engine speed, amount of intake air and engine coolant temperature.

OPERATION

DTC Logic

DTC DETECTION LOGIC

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 between 10.5V and 16V at idle.

>> GO TO 2.

2.PERFORM DTC CONFIRMATION PROCEDURE

CAUTION: Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.

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 the engine and drive vehicle at a speed of 80 km/h (50 MPH) or more for at least 3 consecutive minutes.

NOTE: Keep the vehicle speed as steady as possible during the cruising.

4. Check 1st trip DTC.

Follow the procedure “With CONSULT-III” above.

Is 1st trip DTC detected? YES >> Go to EC-162, "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.CHECK HO2S3 POWER SUPPLY CIRCUIT

1. Disconnect heated oxygen sensor 3 harness connector.

2. Turn ignition switch ON.

3. Check the voltage between HO2S3 harness connector and ground.

Is the inspection result normal? YES >> GO TO 4.

NO >> GO TO 3.

3.DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors F58, F101

• IPDM E/R harness connector F10

• 15A fuse (No. 37)

• Harness for open or short between heated oxygen sensor 3 and fuse

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

4.CHECK HO2S3 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check harness continuity between HO2S3 harness connector and ECM harness connector.

4. Also check harness for short to ground and short to power.

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

NO >> GO TO 5.

5.DETECT MALFUNCTIONING PART

Check the following.

• Harness connectors F58, F101

• Harness for open or short between heated oxygen sensor 3 and ECM

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

6.CHECK HEATED OXYGEN SENSOR 3 HEATER

6.CHECK HEATED OXYGEN SENSOR 3 HEATER Refer to EC-163, "Component Inspection".

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

NO >> GO TO 7.

7.REPLACE HEATED OXYGEN SENSOR 3

Replace heated oxygen sensor 3.

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

>> INSPECTION END

8.CHECK INTERMITTENT INCIDENT

Refer to GI-42, "Intermittent Incident".

>> INSPECTION END

Component Inspection

1.CHECK HEATED OXYGEN SENSOR 3 HEATER

1. Turn ignition switch OFF.

2. Disconnect heated oxygen sensor 3 harness connector.

3. Check resistance between HO2S3 terminals as follows.

Is the inspection result normal? YES >> INSPECTION END

NO >> GO TO 2.

2.REPLACE HEATED OXYGEN SENSOR 3

Replace heated oxygen sensor 3.

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 [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant (commercial service tool).

>> INSPECTION END