P014C
P014C, P014D, P015A, P015B, A/F SENSOR 1
DTC Logic
DTC DETECTION LOGIC
To judge malfunctions, this diagnosis measures response time of the A/F signal computed by ECM from the A/
F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel feedback control constant, and the A/F sensor 1 temperature index. Judgment is based on whether the compensated time (the A/F
signal cycling time index) is inordinately long or not.
DTC CONFIRMATION PROCEDURE
1. PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
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 more than 11 V at idle.
Do you have CONSULT?
YES- GO TO 2.
NO- GO TO 5.
2. PERFORM DTC CONFIRMATION PROCEDURE-1
With CONSULT
1.Start engine and warm it up to normal operating temperature.
2.Turn ignition switch OFF and wait at least 10 seconds.
3.Turn ignition switch ON.
4.Turn ignition switch OFF and wait at least 10 seconds.
5.Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
6.Let engine idle for 1 minute.
7.Increase the engine speed up to about 3,600 rpm and keep it for 10 seconds.
8.Fully release accelerator pedal and then let engine idle for about 1 minute.
9.Check the items status of "DATA MONITOR" as follows.
NOTE:
If "PRSNT" changed to "ABSNT", refer to "Component Function Check" Specification Value.
Is "PRSNT" displayed on CONSULT screen?
YES- GO TO 4.
NO- GO TO 3.
3. PERFORM DTC CONFIRMATION PROCEDURE-2
With CONSULT
Perform DTC confirmation procedure-1 again.
Is "PRSNT" displayed on CONSULT screen?
YES- GO TO 4.
NO- Refer to "Component Function Check" Specification Value.
4. PERFORM DTC CONFIRMATION PROCEDURE-2
With CONSULT
1.Wait for about 20 seconds at idle.
2.Check the items status of "DATA MONITOR" as follows.
NOTE:
If "CMPLT" changed to "INCMP", refer to "Component Function Check" Specification Value.
Is "CMPLT" displayed on CONSULT screen?
YES- GO TO 5.
NO- Refer to "Component Function Check" Specification Value.
5. PERFORM SELF-DIAGNOSIS
With CONSULT
Check the "SELF-DIAG RESULT".
Is any DTC detected?
YES- Proceed to "Diagnosis Procedure" .
NO- INSPECTION END
6. CHECK AIR-FUEL RATIO SELF-LEARNING VALUE
With GST
1.Start engine and warm it up to normal operating temperature.
2.Select Service $01 with GST.
3.Calculate the total value of "Short term fuel trim" and "Long term fuel trim" indications.
Is the total percentage within ±15%?
YES- GO TO 8.
NO- GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.
- Intake air leaks
- Exhaust gas leaks
- Incorrect fuel pressure
- Lack of fuel
- Fuel injector
- Incorrect PCV hose connection
- PCV valve
- Mass air flow sensor
- Repair or replace malfunctioning part.
8. PERFORM DTC CONFIRMATION PROCEDURE
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.Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5.Let engine idle for 1 minute.
6.Increase the engine speed up to about 3,600 rpm and keep it for 10 seconds.
7.Fully release accelerator pedal and then let engine idle for about 1 minute.
8.Check 1st trip DTC.
Is 1st trip DTC detected?
YES- Proceed to "Diagnosis Procedure" .
NO- INSPECTION END
Diagnosis Procedure
1. CHECK GROUND CONNECTION
1.Turn ignition switch OFF.
2.Check ground connection E15. Refer to "Circuit Inspection" Circuit Inspection.
Is the inspection result normal?
YES- GO TO 2.
NO- Repair or replace ground connection.
2. RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1. Refer to "Exploded View" Exploded View.
- GO TO 3.
3. CHECK EXHAUST GAS LEAK
1.Start engine and run it at idle.
2.Listen for an exhaust gas leak before three way catalyst (manifold).
Is exhaust gas leak detected?
YES- Repair or replace.
NO- GO TO 4.
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.
5. CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE
1.Clear the mixture ratio self-learning value. Refer to "Work Procedure" Work Procedure.
2.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" P0171 or "DTC Logic" P0172.
NO- GO TO 6.
6. CHECK AIR FUEL RATIO (A/F) SENSOR 1 POWER SUPPLY CIRCUIT
1.Disconnect 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 8.
NO- GO TO 7.
7. DETECT MALFUNCTIONING PART
Check the following.
- IPDM E/R harness connector F42
- Harness for open or short between A/F sensor 1 and fuse
- Repair or replace harness or connectors.
8. 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 9.
NO- Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to "Component Inspection" P0031.
Is the inspection result normal?
YES- GO TO 10.
NO- GO TO 13.
10. CHECK MASS AIR FLOW SENSOR
Refer to "Component Inspection" P0101.
Is the inspection result normal?
YES- GO TO 11.
NO- Replace mass air flow sensor. Refer to "Removal and Installation" Removal And Installation.
11. CHECK PCV VALVE
Refer to "Inspection" Service and Repair.
Is the inspection result normal?
YES- GO TO 12.
NO- Repair or replace PCV valve. Refer to "Exploded View" Exploded View.
12. CHECK INTERMITTENT INCIDENT
Perform "Intermittent Incident" 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" Exploded View.
CAUTION:
- Discard any 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 sensor, clean exhaust system threads using Oxygen Sensor Thread Cleaner
[commercial service tool (J-43897-18 or J43897-12)] and approved Anti-seize Lubricant (commercial service tool).
- INSPECTION END