For USA and Canada

P0131, P0151 A/F SENSOR 1

DTC Logic


DTC DETECTION LOGIC

To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal is not inordinately low.






DTC CONFIRMATION PROCEDURE


1. PRECONDITIONING

1.Turn ignition switch OFF and wait at least 10 seconds.
2.Turn ignition switch ON.
3.Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:


Before performing the following procedure, confirm that battery voltage is 10.5 V or more at idle.
- GO TO 2.

2. CHECK A/F SENSOR FUNCTION

WITH CONSULT
1.Start engine and warm it up to normal operating temperature.
2.Select "A/F SEN1 (B1)" or "A/F SEN1 (B2)" in "DATA MONITOR" mode with CONSULT.
3.Check "A/F SEN1 (B1)" or "A/F SEN1 (B2)" indication.
WITH GST
Follow the procedure "With CONSULT" above.
Is the indication constantly approx. 0 V?
YES- Go to "Diagnosis Procedure" .
NO- GO TO 3.

3. PERFORM DTC CONFIRMATION PROCEDURE

WITH CONSULT
1.Turn ignition switch OFF and wait at least 10 seconds.
2.Turn ignition switch ON.
3.Turn ignition switch OFF and wait at least 10 seconds.
4.Restart engine.
5.Drive and accelerate vehicle to more than 40 km/h (25 MPH) within 20 seconds after restarting engine.

CAUTION:
Always drive vehicle at a safe speed.
6.Maintain the following conditions for approximately 20 consecutive seconds.





NOTE:
-Keep the accelerator pedal as steady as possible during cruising.
-If this procedure is not completed within 1 minute after restarting engine at step 1, return to step
1.
7.Check 1st trip DTC.
WITH GST
Follow the procedure "With CONSULT" above.
Is 1st trip DTC detected?
YES- Go to "Diagnosis Procedure" .
NO- INSPECTION END


Diagnosis Procedure


1. CHECK AIR FUEL RATIO SENSOR 1 POWER SUPPLY CIRCUIT

1.Disconnect air fuel ratio (A/F) sensor 1 harness connector.
2.Turn ignition switch ON.
3.Check the voltage between A/F sensor 1 harness connector and ground.





Is the inspection result normal?
YES- GO TO 2.
NO- Repair open circuit, short to ground or short to power in harness or connectors.

2. 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.





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





5.Also check harness for short to power.
Is the inspection result normal?
YES- GO TO 3.
NO- Repair open circuit, short to ground or short to power in harness or connectors.

3. CHECK A/F SENSOR 1 GROUND 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.





4.Also check harness for short to power.
Is the inspection result normal?
YES- GO TO 4.
NO- Repair open circuit, short to ground or short to power in harness or connectors.

4. CHECK INTERMITTENT INCIDENT

Perform "Intermittent Incident" Intermittent Incident.
Is the inspection result normal?
YES- GO TO 5.
NO- Repair or replace malfunctioning part.

5. REPLACE A/F SENSOR 1

Replace malfunctioning A/F sensor 1. Refer to "Removal and Installation" Removal and Installation.

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