Diagnosis Procedure
- CHECK GROUND CONNECTION
- Turn ignition switch OFF.
- Check ground connection E21. Refer to Ground Inspection in "CIRCUIT INSPECTION ".
Is the inspection result normal?
YES: GO TO 2.
NO: Repair or replace ground connection.
- RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1. Refer to "REMOVAL AND INSTALLATION ".
GO TO 3.
- CHECK EXHAUST GAS LEAK
- Start engine and run it at idle.
- Listen for an exhaust gas leak before three way catalyst (manifold).
Is exhaust gas leak detected?
YES: Repair or replace.
NO: GO TO 4.
- CHECK FOR INTAKE AIR LEAK
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.
- 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 ".
- Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P172 detected? Is it difficult to start engine?
YES: Perform trouble diagnosis for DTC P0171 or P0172. Refer to "DTC LOGIC " or "DTC LOGIC ".
NO: GO TO 6.
- CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
- Disconnect A/F sensor 1 harness connector.
- Turn ignition switch ON.
- Check the voltage between A/F sensor 1 harness connector and ground.TERMINALS VOLTAGE REFERENCE
A/F sensor 1 Ground Voltage Connector Terminal F27 4 Ground Battery voltage
Is the inspection result normal?
YES: GO TO 8.
NO: GO TO 7.
- DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E6, F123
- IPDM E/R harness connector E14
- 15A fuse (No. 63)
- Harness for open or short between A/F sensor 1 and fuse
Repair or replace harness or connectors.
- CHECK A/F SENSOR 1 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
- Turn ignition switch OFF.
- Disconnect ECM harness connector.
- Check the continuity between A/F sensor 1 harness connector and ECM harness connector.TERMINALS CONTINUITY REFERENCE
A/F sensor 1 ECM Continuity Connector Terminal Connector Terminal F27 1 F8 45 Existed 2 49 - Check the continuity between A/F sensor 1 harness connector or ECM harness connector and ground.TERMINALS CONTINUITY REFERENCE
A/F sensor 1 ECM Ground Continuity Connector Terminal Connector Terminal F27 1 F8 45 Ground Not existed 2 49 - 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.
- CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to "COMPONENT INSPECTION ".
Is the inspection result normal?
YES: GO TO 10.
NO: GO TO 13.
- CHECK MASS AIR FLOW SENSOR
Check mass air flow sensor.
Refer to "COMPONENT INSPECTION ".
Is the inspection result normal?
YES: GO TO 11.
NO: Replace mass air flow sensor.
- CHECK PCV VALVE
Refer to "COMPONENT INSPECTION ".
Is the inspection result normal?
YES: GO TO 12.
NO: Repair or replace PCV valve.
- CHECK INTERMITTENT INCIDENT
Perform "INTERMITTENT INCIDENT ".
Is the inspection result normal?
YES: GO TO 13.
NO: Repair or replace.
- REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace air fuel ratio (A/F) sensor 1.
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 tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
INSPECTION END