Diagnosis Procedure

1. CHECK GROUND CONNECTION
   1. Turn ignition switch OFF.
   2. Check ground connection M95. Refer to Ground Inspection in "CIRCUIT INSPECTION ".

      Is the inspection result normal? 

      YES: GO TO 2.

      NO: Repair or replace ground connection.

2. RETIGHTEN A/F SENSOR 1 AND HEATED OXYGEN SENSOR 2
   1. Loosen and retighten the A/F sensor 1 and heated oxygen sensor 2. Refer to "REMOVAL AND INSTALLATION ".

      GO TO 3.

3. CHECK FOR EXHAUST GAS LEAK
   1. Start 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.

      NO: GO TO 4.

4. 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: Repair or replace.

      NO: GO TO 5.

5. CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE
   1. Clear the mixture ratio self-learning value. Refer to "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, P0172, P0174 or P0175 detected? Is it difficult to start engine? 

      YES: Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to "DIAGNOSIS PROCEDURE " or "DIAGNOSIS PROCEDURE ".

      NO: GO TO 6.

6. 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 7.

      NO: Repair or replace harness connector.

7. 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.

      DTC	A/F sensor 1			Ground	Voltage
      	Bank	Connector	Terminal
      P2A00	1	F3	4	Ground	Battery voltage
      P2A03	2	F20	4

      Is the inspection result normal? 

      YES: GO TO  9.

      NO: GO TO 8.

8. DETECT MALFUNCTIONING PART

   Check the following.

   • Harness connectors E3, F1
   • IPDM E/R harness connector E7
   • 15 A fuse (No. 46)
   • Harness for open or short between A/F sensor 1 and fuse

   Repair or replace harness or connectors.

9. 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.

      DTC	A/F sensor 1			ECM		Continuity
      	Bank	Connector	Terminal	Connector	Terminal
      P2A00	1	F3	1	F102	57	Existed
      			2		61
      P2A03	2	F20	1		65
      			2		66

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

      DTC	A/F sensor 1			Ground	Continuity
      	Bank	Connector	Terminal
      P2A00	1	F3	1	Ground	Not existed
      			2
      P2A03	2	F20	1
      			2

      DTC	ECM			Ground	Continuity
      	Bank	Connector	Terminal
      P2A00	1	F102	57	Ground	Not existed
      			61
      P2A03	2		65
      			66

   5. Also check harness for short to power.

      Is the inspection result normal? 

      YES: GO TO 10.

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

10. CHECK A/F SENSOR 1 HEATER

    Refer to "COMPONENT INSPECTION ".

    Is the inspection result normal? 

    YES: GO TO 11.

    NO: GO TO  13.

11. CHECK HEATED OXYGEN SENSOR 2

    Check heated oxygen sensor 2. Refer to "COMPONENT INSPECTION ".

    Is the inspection result normal? 

    YES: GO TO 12.

    NO: Replace malfunctioning heated oxygen sensor 2. Refer to "EXPLODED VIEW ".

12. CHECK INTERMITTENT INCIDENT

    Perform "INTERMITTENT INCIDENT ".

    Is the inspection result normal? 

    YES: GO TO 13.

    NO: Repair or replace.

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

    Replace air fuel ratio (A/F) sensor 1. Refer to "EXPLODED VIEW ".

    CAUTION:

    • Discard any A/F 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 A/F 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).

    Do you have CONSULT? 

    YES: GO TO 14.

    NO: GO TO  15.

14. CONFIRM A/F ADJUSTMENT DATA

    With CONSULT 

    1. Turn ignition switch ON.
    2. Select "A/F ADJ-B1" and "A/F ADJ-B2" in "DATA MONITOR" mode with CONSULT.
    3. Make sure that "0.000" is displayed on CONSULT screen.

       Is "0.000" displayed? 

       YES: INSPECTION END

       NO: GO TO 15.

15. CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE

    Clear the mixture ratio self-learning value. Refer to "MIXTURE RATIO SELF-LEARNING VALUE CLEAR: SPECIAL REPAIR REQUIREMENT ".

    Do you have CONSULT? 

    YES: GO TO 16.

    NO: INSPECTION END

16. CONFIRM A/F ADJUSTMENT DATA

    With CONSULT 

    1. Turn ignition switch ON.
    2. Select "A/F ADJ-B1" and "A/F ADJ-B2" in "DATA MONITOR" mode with CONSULT.
    3. Make sure that "0.000" is displayed on CONSULT screen.

INSPECTION END