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

for Preparation Click here

DESCRIPTION

HINT:

Sensor 1 refers to the sensor mounted in front of the Three-Way Catalytic Converter (TWC) and located near the engine assembly.

CONFIRMATION DRIVING PATTERN

HINT:

Performing this confirmation pattern will activate the air fuel ratio sensor response monitor.

1. Connect the intelligent tester to the DLC3.
   
2. Turn the ignition switch to ON.
   
3. Turn the tester on.
   
4. Clear the DTCs (Click here).
   
5. Turn the ignition switch off and wait for at least 30 seconds.
   
6. Start the engine and warn it up (until the engine coolant temperature 75°C (167°F)). [A]
   
7. Turn the tester on.
   
8. Drive the vehicle at between 64 km/h and 120 km/h (40 mph and 75 mph) for 3 minutes. However, the vehicle should be driven at a constant speed. [B]
   

   CAUTION:

   When performing the confirmation driving pattern, obey all speed limits and traffic laws.

9. Enter the following menus: Powertrain / Engine and ECT / DTC / Pending.
   
10. Read the pending DTC.
    
11. If a pending DTC is output, the system is malfunctioning.
    

    HINT:

    If a pending DTC is not output, perform the following procedure.

12. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
    
13. Input the DTC P2A00.
    
14. Check the DTC judgment result.
    
    

    Intelligent Tester 

    Tester Display	Description
    NORMAL	DTC judgment completed System normal
    ABNORMAL	DTC judgment completed System abnormal
    INCOMPLETE	DTC judgment not completed Perform driving pattern after confirming DTC enabling conditions
    UNKNOWN	Unable to perform DTC judgment Number of DTCs which do not fulfill DTC preconditions has reached ECU's memory limit

    HINT:

    1. If the judgment result shows ABNORMAL, the system has a malfunction.
       
    2. If the judgment result shows INCOMPLETE or UNKNOWN, perform step [B] and check the DTC judgment result again.
       

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

HINT:

Malfunctioning areas can be identified by performing the Control the Injection Volume for A/F Sensor function provided in the Active Test. The Control the Injection Volume for A/F Sensor function can help to determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.

The following instructions describe how to conduct the Control the Injection Volume for A/F Sensor operation using the intelligent tester.

1. Connect the intelligent tester to the DLC3.
   
2. Start the engine and turn the tester on.
   
3. Warm up the engine at an engine speed of 2500 rpm for approximately 90 seconds.
   
4. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor.
   
5. Perform the Active Test operation with the engine in an idling condition (press the RIGHT or LEFT button to change the fuel injection volume.)
   
6. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AF Voltage B1S1 and O2S B1S2) displayed on the tester.
   

HINT:

1. The Control the Injection Volume for A/F Sensor operation lowers the fuel injection volume by 12.5% or increases the injection volume by 25%.
   
2. Each sensor reacts in accordance with increases and decreases in the fuel injection volume.
   

NOTICE:

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.

Case	A/F Sensor (Sensor 1) Output Voltage	HO2 Sensor (Sensor 2) Output Voltage	Main Suspected Trouble Area
1			-
2			Air fuel ratio sensor Air fuel ratio sensor heater Air fuel ratio sensor circuit
3			Heated oxygen sensor Heated oxygen sensor heater Heated oxygen sensor circuit Gas leak from exhaust system
4			Injector Fuel pressure Gas leak from exhaust system (Air-fuel ratio extremely rich or lean)

1. Following the Control the Injection Volume for A/F Sensor procedure enables technicians to check and graph the voltage outputs of both the air fuel ratio and heated oxygen sensors.
   
2. To display the graph, enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Injection Volume for A/F Sensor / A/F Control System / AF Voltage B1S1 and O2S B1S2.
   

HINT:

1. DTC P2A00 may be set when the air fuel ratio is stuck rich or lean.
   
2. A low air fuel ratio sensor voltage could be caused by a rich air fuel mixture. Check for conditions that would cause the engine to run rich.
   
3. A high air fuel ratio sensor voltage could be caused by a lean air fuel mixture. Check for conditions that would cause the engine to run lean.
   
4. Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air fuel ratio was lean or rich, and other data from the time the malfunction occurred.
   

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the tester on.
   

4. Enter the following menus: Powertrain / Engine and ECT / DTC.
   

5. Read 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	GO TO DTC CHART (Click here)

A

1. Disconnect the air fuel ratio sensor connector.
   

2. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   1 (HA1A) - 2 (+B)	20°C (68°F)	1.8 to 3.4 Ω
   1 (HA1A) - 4 (A1A-)	Always	10 kΩ or higher

   Text in Illustration 

   *1	Component without harness connected (Air Fuel Ratio Sensor)

3. Reconnect the air fuel ratio sensor.
   

NG	REPLACE AIR FUEL RATIO SENSOR (Click here)

OK

1. Disconnect the air fuel ratio sensor connector.
   

2. Turn the ignition switch to ON.
   

3. Measure the voltage according to the value(s) in the table below.
   

   Standard Voltage:

   Tester Connection	Switch Condition	Specified Condition
   B34-2 (+B) - Body ground	Ignition switch ON	11 to 14 V

4. Turn the ignition switch off.
   

5. Disconnect the ECM connector.
   

6. Measure the resistance according to the value(s) in the table below.
   

   Standard Resistance (Check for Open):

   Tester Connection	Condition	Specified Condition
   B34-3 (A1A+) - B8-103 (A1A+)	Always	Below 1 Ω
   B34-4 (A1A-) - B8-126 (A1A-)	Always	Below 1 Ω
   B34-1 (HA1A) - B8-104 (HA1A)	Always	Below 1 Ω

   Standard Resistance (Check for Short):

   Tester Connection	Condition	Specified Condition
   B34-3 (A1A+) or B8-103 (A1A+) - Body ground	Always	10 kΩ or higher
   B34-4 (A1A-) or B8-126 (A1A-) - Body ground	Always	10 kΩ or higher
   B34-1 (HA1A) or B8-104 (HA1A) - Body ground	Always	10 kΩ or higher

7. Reconnect the ECM connector.
   

8. Reconnect the air fuel ratio sensor connector.
   

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

1. Perform the confirmation driving pattern.
   

   HINT:

   Refer to "CONFIRMATION DRIVING PATTERN".

   Result 

   Result	Proceed to
   NORMAL	A
   ABNORMAL	B

B	Go to step 5

A
CHECK FOR INTERMITTENT PROBLEMS (Click here)

1. Replace the air fuel ratio sensor (Click here).
   

NEXT

1. Perform the confirmation driving pattern.
   

   HINT:

   Refer to "CONFIRMATION DRIVING PATTERN".

   Result 

   Result	Proceed to
   NORMAL	A
   ABNORMAL	B

B	Go to step 7

A
END

1. Connect the intelligent tester to the DLC3.
   

2. Turn the ignition switch to ON.
   

3. Turn the tester on.
   

4. Start the engine and warm it up until the engine coolant temperature reaches 75°C (167°F) or more.
   

   HINT:

   The A/C switch and all accessory switches should be off.

5. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the EGR Step Position.
   

6. Check the MAP and Engine Speed in Date List at the idling condition while performing Active Test.
   

   OK:

   MAP and idling condition change in response to EGR step position.
   

   
   

   Standard:

   
   

   -	EGR Step Position (Active Test)
   	0 Steps	0 to 30 Steps
   Idling condition	Steady idling	Idling changes from steady to rough idling
   MAP (Data List)	MAP value is 20 to 40 kPa (150 to 300 mmHg) (EGR valve is fully closed)	MAP value is at least +10 kPa (75 mmHg) higher than when EGR valve is fully closed

   HINT:

   1. Do not leave the EGR valve open for 10 seconds or more during the Active Test
      
   2. Be sure to return the EGR valve to step 0 when Active Test is completed.
      

   Result 

   Result	Proceed to
   NG	A
   OK	B

B	Go to step 9

A

1. Remove the EGR valve assembly (Click here).
   

2. Check for contamination between the EGR valve and housing.
   

   OK:

   No leaks or blockage
   

3. Reinstall the EGR valve assembly (Click here).
   

NG	REPLACE EGR VALVE ASSEMBLY (Click here)

OK

1. Replace the ECM (Click here).
   

NEXT

1. Perform the confirmation driving pattern.
   

   HINT:

   Refer to the CONFIRMATION DRIVING PATTERN.

   Result 

   Result	Proceed to
   NORMAL	A
   ABNORMAL	B

B	REPLACE ECM (Click here)

A
END