Diagnosis Procedure
- RETIGHTEN AIR FUEL RATIO SENSOR 1
Loosen and retighten the air fuel ratio (A/F) sensor 1. Refer to "EXPLODED VIEW ".
: GO TO 2.
- CHECK EXHAUST GAS LEAKAGE
- Start engine and run it at idle.
- Listen for an exhaust gas leakage before three way catalyst (manifold).
Is exhaust gas leakage detected?
YES: Repair or replace malfunctioning part.
NO: GO TO 3.
- CHECK FOR INTAKE AIR LEAKAGE
Listen for an intake air leakage after the mass air flow sensor.
Is intake air leakage detected?
YES: Repair or replace malfunctioning part.
NO: GO TO 4.
- CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE
- Clear the mixture ratio self-learning value. Refer to "WORK PROCEDURE ".
- 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 "DTC LOGIC " or "DTC LOGIC ".
NO: GO TO 5.
- CHECK AIR FUEL RATIO SENSOR 1 POWER SUPPLY CIRCUIT
- Disconnect air fuel ratio (A/F) sensor 1 harness connector.
- Turn ignition switch ON.
- Check the voltage between A/F sensor 1 harness connector and ground.
DTC A/F sensor 1 Ground Voltage Bank Connector Terminal P0133 1 F23 4 Ground 3.0 V P0153 2 F24 4 Is the inspection result normal?
YES: GO TO 6.
NO: Repair open circuit, short to ground or short to power in 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.
DTC A/F sensor 1 ECM Continuity Bank Connector Terminal Connector Terminal P0133 1 F23 3 F111 88 Existed P0153 2 F24 3 78 - Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector and ground.
DTC A/F sensor 1 ECM Ground Continuity Bank Connector Terminal Connector Terminal P0133 1 F23 3 F111 88 Ground Not existed P0153 2 F24 3 78 - Also check harness for short to power.
Is the inspection result normal?
YES: GO TO 7.
NO: Repair open circuit, short to ground or short to power in harness or connectors.
- CHECK A/F SENSOR 1 GROUND 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.
DTC A/F sensor 1 ECM Continuity Bank Connector Terminal Connector Terminal P0133 1 F23 6 F111 94 Existed P0153 2 F24 6 74 - Also check harness for short to power.
Is the inspection result normal?
YES: GO TO 8.
NO: Repair open circuit, short to ground or short to power in harness or connectors.
- CHECK A/F SENSOR 1 HEATER
Refer to "COMPONENT INSPECTION (A/F SENSOR 1 HEATER) ".
Is the inspection result normal?
YES: GO TO 9.
NO: GO TO 12.
- CHECK MASS AIR FLOW SENSOR
Check both mass air flow sensor (bank 1) and mass air flow sensor (bank 2).
Refer to "COMPONENT INSPECTION (MAF SENSOR) ".
Is the inspection result normal?
YES: GO TO 10.
NO: Replace malfunctioning mass air flow sensor. Refer to. "EXPLODED VIEW ".
- CHECK PCV VALVE
Refer to "INSPECTION ".
Is the inspection result normal?
YES: GO TO 11.
NO: Repair or replace PCV valve. Refer to "EXPLODED VIEW ".
- CHECK INTERMITTENT INCIDENT
Refer to "INTERMITTENT INCIDENT ".
Is the inspection result normal?
YES: GO TO 12.
NO: Repair or replace malfunctioning part.
- REPLACE A/F SENSOR 1
Replace malfunctioning 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).
: INSPECTION END