Nissan Sentra B18 (2020-2025) Service Manual: P2097 A/f Sensor 1

Dtc Description

DTC DETECTION LOGIC

POSSIBLE CAUSE

• A/F sensor 1

• A/F sensor 1 heater

• Heated oxygen sensor 2

• Fuel pressure

• Fuel injector

• Intake air leaks

• Exhaust gas leaks

FAIL-SAFE

Not applicable

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 11 at idle.

   >>

   GO TO 2.

2. PERFORM DTC CONFIRMATION PROCEDURE

   1. Clear the mixture ratio self-learning value. Refer to Work Procedure.

   2. Turn ignition switch OFF and wait at least 10 seconds.

   3. Start the 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 >>

   Refer to DTC Diagnosis Procedure.

   NO-1 >>

   To check malfunction symptom before repair: Refer to Intermittent Incident.

   NO-2 >>

   Confirmation after repair: INSPECTION END

Dtc Diagnosis Procedure

1. CHECK HARNESS CONNECTOR

   1. Turn ignition switch OFF.

   2. Disconnect air fuel ratio (A/F) sensor 1 harness connector.

   3. Check harness connector for water.

      Water should not exit.

   Is the inspection result normal?

   YES >>

   GO TO 2.

   NO >>

   Repair or replace harness connector.

2. RETIGHTEN A/F SENSOR 1 AND HEATED OXYGEN SENSOR 2

   Loosen and retighten the A/F sensor 1 and heated oxygen sensor 2. Refer to Exploded View. (A/F sensor 1), Refer to Exploded View. (heated oxygen sensor 2).

   >>

   GO TO 3.

3. CHECK FOR EXHAUST GAS LEAK

   1. Start the engine and run it at idle.

   2. Listen for an exhaust gas leak before the three way catalyst 2.

   Is exhaust gas leak detected?

   YES >>

   Repair or replace malfunctioning part.

   NO >>

   GO TO 4.

4. CHECK FOR INTAKE AIR LEAK

   1. Stop engine.

   2. Reconnect A/F sensor 1 harness connector.

   3. Start the engine and run it at idle.

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

   Is intake air leak detected?

   YES >>

   Repair or replace malfunctioning part.

   NO >>

   GO TO 5.

5. CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

   1. Clear the mixture ratio self-learning value. Refer to Work Procedure.

   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 P0171 or P0172. Refer to DTC Description or DTC Description.

   NO >>

   GO TO 6.

6. CHECK A/F SENSOR 1 POWER SUPPLY

   1. Turn ignition switch OFF.

   2. Disconnect A/F sensor 1 harness connector.

   3. Turn ignition switch ON.

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

      +		−	Voltage
      A/F sensor 1
      Connector	Terminal
      F12	4	Ground	Battery voltage

   Is the inspection result normal?

   YES >>

   GO TO 8.

   NO >>

   GO TO 7.

7. CHECK A/F SENSOR 1 POWER SUPPLY CIRCUIT

   1. Turn ignition switch OFF.

   2. Disconnect IPDM E/R harness connector.

   3. Check the continuity between A/F sensor 1 harness connector and IPDM E/R harness connector .

      A/F sensor 1		IPDM E/R		Continuity
      Connector	Terminal	Connector	Terminal
      F12	4	F96	75	Existed

   4. Also check harness for short to ground.

   Is the inspection result normal?

   YES >>

   Perform the trouble diagnosis for power supply circuit.

   NO >>

   Repair or replace malfunctioning part.

8. CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT

   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 .

      A/F sensor 1		ECM		Continuity
      Connector	Terminal	Connector	Terminal
      F12	1	F25	86	Existed
      	2		88

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

      A/F sensor 1		—	Continuity
      Connector	Terminal
      F12	1	Ground	Not existed
      	2

      ECM		—	Continuity
      Connector	Terminal
      F25	86	Ground	Not existed
      	88

   5. Also check harness for short to power.

   Is the inspection result normal?

   YES >>

   GO TO 9.

   NO >>

   Repair or replace malfunctioning part.

9. CHECK A/F SENSOR 1 HEATER

   Refer to Component Inspection.

   Is the inspection result normal?

   YES >>

   GO TO 10.

   NO >>

   GO TO 11.

10. CHECK HEATED OXYGEN SENSOR 2

    Refer to Component Inspection.

    Is the inspection result normal?

    YES >>

    GO TO 12.

    NO >>

    Replace heated oxygen sensor 2. Refer to Exploded View.

11. REPLACE A/F SENSOR 1

    Refer to Exploded View.

    Do you have CONSULT?

    YES >>

    GO TO 12.

    NO >>

    GO TO 13.

12. CONFIRM A/F ADJUSTMENT DATA

    With CONSULT

    1. Turn ignition switch ON.

    2. Select “A/F ADJ-B1” in “DATA MONITOR” mode of “ENGINE” using CONSULT.

    3. Make sure that “0.000” is displayed on CONSULT 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 Work Procedure.

    Do you have CONSULT?

    YES >>

    GO TO 14.

    NO >>

    INSPECTION END

14. CONFIRM A/F ADJUSTMENT DATA

    With CONSULT

    1. Turn ignition switch ON.

    2. Select “A/F ADJ-B1” in “DATA MONITOR” mode of “ENGINE” using CONSULT.

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

    >>

    INSPECTION END

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