DTC P2A00: A/F Sensor Circuit Slow Response (Bank 1 Sensor 1): Procedure

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
5. Read the DTCs.

   Result

   Result	Proceed to
   DTC P2A00 is output	A
   DTC P2A00 and other DTCs are output	B

   HINT: 

   If any DTCs other than P2A00 are output, troubleshoot those DTCs first.

B → See step   13 

A: Go to next step 

1. Connect the Techstream to the DLC3.
2. Start the engine.
3. Turn the Techstream on.
4. Warm up the engine and run the engine at an engine speed of 2500 rpm for approximately 90 seconds.
5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume / Gas AF Control / AFS Voltage B1S1 and O2S B1S2.
6. Perform the Control the Injection Volume operation with the engine idling.
7. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS Voltage B1S1 and O2S B1S2) displayed on the Techstream.

   HINT: 

   • Change the fuel injection volume within the range of -12% to +12%. The injection volume can be changed in fine gradations.
   • The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor has a maximum output delay of approximately 20 seconds.
   • If the sensor output voltage does not change (almost no reaction) while performing the Active Test, the sensor may be malfunctioning.

   Techstream Display (Sensor)	Injection Volume	Status	Voltage
   AFS Voltage B1S1 (Air fuel ratio)	+12%	Rich	Below 3.1 V
   AFS Voltage B1S1 (Air fuel ratio)	-12%	Lean	Higher than 3.4 V
   O2S B1S2 (Heated oxygen)	+12%	Rich	Higher than 0.55 V
   O2S B1S2 (Heated oxygen)	-12%	Lean	Below 0.4 V

   RESULT
   
   

   Status of AFS Voltage B1S1	Status of O2S B1S2	Air Fuel Ratio Condition and Air Fuel Ratio Sensor Condition	Proceed to
   Lean/Rich	Lean/Rich	Normal	A
   Lean	Lean	Actual air fuel ratio lean	B
   Rich	Rich	Actual air fuel ratio rich	B
   Lean	Lean/Rich	Air fuel ratio sensor malfunction	C
   Rich	Lean/Rich	Air fuel ratio sensor malfunction	C

   • Lean: During the Control the Injection Volume Active Test, the air fuel ratio sensor output voltage (AFS Voltage B1S1) is consistently higher than 3.4 V, and the heated oxygen sensor output voltage (O2S B1S2) is consistently below 0.4 V.
   • Rich: During the Control the Injection Volume Active Test, the AFS Voltage B1S1 is consistently below 3.1 V, and the O2S B1S2 is consistently higher than 0.55 V.
   • Lean/Rich: During the Control the Injection Volume Active Test, the output voltage of the heated oxygen sensor alternates correctly.

   HINT: 

   Refer to "Data List / Active Test" [AFS Voltage B1S1 and O2S B1S2]. Refer to DATA LIST / ACTIVE TEST .

B → See step   4 

C → See step   8 

A: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear the DTCs. Refer to DTC CHECK / CLEAR .
5. Turn the ignition switch off and wait for at least 30 seconds.
6. Turn the ignition switch to ON.
7. Turn the Techstream on.
8. Start the engine and warm it up.
9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
11. Input the DTC: P2A00.
12. Check the DTC judgment result.
    RESULT
    
    

    Result	Proceed to
    NORMAL (DTC is not output)	A
    ABNORMAL (DTC P2A00 is output)	B

B → See step   8 

A → See step   14 

NG → See step   15 

OK: Go to next step 

1. Check the intake system. Refer to ON-VEHICLE INSPECTION .

NG → REPAIR OR REPLACE INTAKE SYSTEM 

OK: Go to next step 

1. Check the fuel pressure. Refer to ON-VEHICLE INSPECTION - Step 2 .

NG → See step   12 

OK: Go to next step 

1. Inspect the fuel injector assembly. Refer to INSPECTION .

NG → See step   16 

OK: Go to next step 

1. Replace the air fuel ratio sensor. Refer to REMOVAL .

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear the DTCs. Refer to DTC CHECK / CLEAR .
5. Turn the ignition switch off and wait for at least 30 seconds.
6. Turn the ignition switch to ON.
7. Turn the Techstream on.
8. Start the engine and warm it up.
9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
11. Input the DTC: P2A00.
12. Check the DTC judgment result.
    RESULT
    
    

    Result	Proceed to
    ABNORMAL (DTC P2A00 is output)	A
    NORMAL (DTC is not output)	B

B → END 

A: Go to next step 

1. Replace the ECM. Refer to REMOVAL .

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Turn the Techstream on.
4. Clear the DTCs. Refer to DTC CHECK / CLEAR .
5. Turn the ignition switch off and wait for at least 30 seconds.
6. Turn the ignition switch to ON.
7. Turn the Techstream on.
8. Start the engine and warm it up.
9. Drive the vehicle in accordance with the driving pattern described in Confirmation Driving Pattern.
10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
11. Input the DTC: P2A00.
12. Check that the DTC judgment result is NORMAL.

NEXT → END 

1. Check the fuel lines for leaks or blockage.

NG → REPAIR OR REPLACE FUEL LINE 

OK → See step   17