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

DESCRIPTION

CONFIRMATION DRIVING PATTERN

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FOR ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P2A00)

INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

CHECK HARNESS AND CONNECTOR (AIR FUEL RATIO SENSOR - ECM)

PERFORM CONFIRMATION DRIVING PATTERN

CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)

REPLACE AIR FUEL RATIO SENSOR

PERFORM CONFIRMATION DRIVING PATTERN

CHECK WHETHER DTC OUTPUT RECURS (DTC P2A00)

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 driving 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 and turn the intelligent tester on [A].
   
3. Enter the following menus: Powertrain / Engine and ECT / DTC / Clear.
   
4. Clear DTCs.
   
5. Start the engine and warm it up until the engine coolant temperature is 75°C (167°F) or higher [B].
   
6. Drive the vehicle at 60 km/h (37 mph) or more for 20 minutes or more [C].
   

   CAUTION:

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

   HINT:

   1. This step is performed to complete ethanol concentration learning.
      
   2. If DTC P2A00 is output when any of the following conditions is met, it is necessary to complete ethanol concentration learning to meet preconditions.
      
   1. The battery has been disconnected and reconnected.
      
   2. The DTCs have been cleared.
      
   3. Both fuel tank assemblies (main and sub tanks) have been filled with fuel.
      
7. Drive the vehicle at a constant speed between 64 km/h and 120 km/h (40 mph and 75 mph) for 10 minutes or more [D].
   
8. Turn the ignition switch off.
   
9. Repeat steps [B] and [D] above.
   
10. Enter the following menus: Powertrain / Engine and ECT / DTC.
    
11. Check if any DTCs (any pending DTCs) are output.
    

WIRING DIAGRAM

INSPECTION PROCEDURE

HINT:

Intelligent tester only:

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 determine whether the air fuel ratio sensor, heated oxygen sensor and other potential trouble areas are malfunctioning.

1. Connect the intelligent tester to the DLC3.
   
2. Start the engine.
   
3. Turn the tester on.
   
4. Warm up 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 for A/F Sensor.
   
6. Perform the "Control the Injection Volume for A/F Sensor" operation with the engine idling (press the RIGHT or LEFT button to change the fuel injection volume).
   
7. Monitor the output voltages of the air fuel ratio and heated oxygen sensors (AFS 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 12.5%.
   
2. The sensors react in accordance with increases and decreases in the fuel injection volume.
   

Standard:

Tester Display (Sensor)	Injection Volume	Status	Voltage
AFS Voltage B1S1 (Air fuel ratio sensor)	+12.5%	Rich	Below 3.1 V
	-12.5%	Lean	Higher than 3.4 V
O2S B1S2 (Heated oxygen sensor)	+12.5%	Rich	Higher than 0.55 V
	-12.5%	Lean	Below 0.4 V

NOTICE:

The air fuel ratio sensor has an output delay of a few seconds and the heated oxygen sensor (sensor 2) output has a maximum output delay of approximately 20 seconds.

Case	Air Fuel Ratio Sensor (Sensor 1) Output Voltage	Heated Oxygen 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
4			Fuel injector assembly 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 / View / AFS Voltage B1S1 and O2S B1S2.
   

HINT:

1. Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. 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.
   
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.
   

NOTICE:

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

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 relating to the A/F sensor (DTCs for the A/F sensor heater or A/F sensor admittance) are output, troubleshoot those DTCs first.

1. Inspect the air fuel ratio sensor (HILUX_TGN26 RM000001421010X.html).
   

1. Disconnect the air fuel ratio sensor connector.
   

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

   Standard Voltage:

   Tester Connection	Switch Condition	Specified Condition
   C85-2 (+B) - Body ground	Ignition switch ON	11 to 14 V

3. Turn the ignition switch off.
   

4. Disconnect the ECM connector.
   

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

   Standard Resistance (Check for Open):

   Tester Connection	Condition	Specified Condition
   C85-3 (A1A+) - C97-7 (A1A+)	Always	Below 1 Ω
   C85-4 (A1A-) - C97-1 (A1A-)	Always	Below 1 Ω
   C85-1 (HA1A) - C97-6 (HA1A)	Always	Below 1 Ω

   Standard Resistance (Check for Short):

   Tester Connection	Condition	Specified Condition
   C85-3 (A1A+) or C97-7 (A1A+) - Body ground	Always	10 kΩ or higher
   C85-4 (A1A-) or C97-1 (A1A-) - Body ground	Always	10 kΩ or higher
   C85-1 (HA1A) or C97-6 (HA1A) - Body ground	Always	10 kΩ or higher

6. Reconnect the ECM connector.
   

7. Reconnect the air fuel ratio sensor connector.
   

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 is not output	B

1. Replace the air fuel ratio sensor (HILUX_TGN26 RM00000142300ZX.html).
   

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 is not output	A
   DTC P2A00 is output	B