GSIC - Global Service Information Center

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

### DTC P2A03 A/F Sensor Circuit Slow Response (Bank 2 Sensor 1)

## for Preparation Click here

## DESCRIPTION

Refer to DTC P2195 (Click here).

DTC No. | DTC Detection Condition | Trouble Area

P2A00
P2A03

Calculated test value for A/F sensor response rate deterioration level is less threshold

1. Open or short in A/F sensor (bank 1, 2 sensor 1)
2. A/F sensor (bank 1, 2 sensor1)
3. ECM

## WIRING DIAGRAM

## INSPECTION PROCEDURE

HINT:

  Intelligent tester only:

  Malfunctioning areas can found by performing the Active Test / Control the Injection volume for A/F sensor operation. The "Control the injection volume for A/F sensor" operation can determine if the A/F sensor, heated oxygen sensor or other potential trouble areas are malfunctioning or not.

Perform Active Test using the intelligent tester.

HINT:

  "Control the injection volume for A/F sensor" is an Active Test which changes the injection volume to -12.5% or +25%.

1. Connect the intelligent tester to the DLC3.
2. Start the engine and turn the tester ON.
3. Warm up the engine by running the engine at 2,500 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. Enter the following monitor items: AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2.
6. Perform the "Control the injection volume for A/F sensor" operation with the engine in a idling condition (press the right or left button).

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 %.

1. Each sensor reacts in accordance with increases and decreases in the fuel injection volume.

Standard:
Tester Display (Sensor) | Injection Volume | Status | Voltage
AFS B1S1 or AFS B2S1 (A/F) | +25 % | Rich | Less than 3.0
AFS B1S1 or AFS B2S1 (A/F) | -12.5 % | Lean | More than 3.35
O2S B1S2 or O2S B2S2 (heated oxygen sensor) | +25 % | Rich | More than 0.55
O2S B1S2 or O2S B2S2 (heated oxygen sensor) | -12.5 % | Lean | Less than 0.4

NOTICE:

  The A/F 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 | Heated Oxygen Sensor (Sensor 2) Output Voltage | Main Suspected Trouble Areas
1 | Injection volume +25 % -12.5 % |  | Injection volume +25 % -12.5 % |  | -
Output voltage More than 3.35 V Less than 3.0 V |  | Output voltage More than 0.55 V Less than 0.4 V |

2

Injection volume
+25 %
-12.5 %

Injection volume
+25 %
-12.5 %

1. A/F sensor
2. A/F sensor heater
   A/F sensor circuit

Output voltage Almost no reaction |  | Output voltage More than 0.55 V Less than 0.4 V |

3

Injection volume
+25 %
-12.5 %

Injection volume
+25 %
-12.5 %

1. Heated oxygen sensor
2. Heated oxygen sensor heater
3. Heated oxygen sensor circuit

Output voltage More than 3.35 V Less than 3.0 V |  | Output voltage Almost no reaction |

4

Injection volume
+25 %
-12.5 %

Injection volume
+25 %
-12.5 %

1. Injector
2. Fuel pressure
3. Gas leakage from exhaust system
   (air-fuel ratio extremely lean or rich)

Output voltage Almost no reaction |  | Output voltage Almost no reaction |

1. Following the A/F CONTROL procedure enables technicians to check and graph the voltage outputs of both the A/F and heated oxygen sensors.
2. Enter the following menus on the tester: Powertrain / Engine and ECT / Active Test / Control the injection volume for A/F sensor and Data List / AFS B1S1 and O2S B1S2 or AFS B2S1 and O2S B2S2.

HINT:

1. Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was running or stopped, 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. These DTCs are related to the A/F sensor.
3. These DTCs are recorded when A/F sensor has malfunction, although the caption is oxygen sensor.

1.CHECK OTHER DTC OUTPUT (BESIDES A/F SENSOR DTC)

1. Connect the intelligent tester to the DLC3.

1. Turn the ignition switch ON and turn the tester ON.

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

1. Read DTCs.

   Result:

     Display | Proceed to
     DTC P2A00 and/or P2A03 are output | A
     DTC P2A00 and/or P2A03 and other codes are output | B

   HINT:
     If any other code besides P2A00 and/or P2A03 are output, perform troubleshooting for those DTCs first.

| B |

GO TO RELEVANT DTC CHART

A |

2.INSPECT AIR FUEL RATIO SENSOR (HEATER RESISTANCE)

1. Disconnect the A/F sensor connector.

1. Measure the resistance of the A/F sensor.

   Standard resistance:

     Tester Connection | Condition | Specified Condition
     1 (HT) - 2 (+B) | 20°C (68°F) | 1.8 to 3.4 Ω at 20°C (68°F)
     1 (HT) - 4 (AF-) | - | 10 kΩ or higher

| NG |

REPLACE AIR FUEL RATIO SENSOR

OK |

3.CHECK WIRE HARNESS (A/F SENSOR -ECM)

1. Disconnect the A18 or A25 A/F sensor connector.

1. Disconnect the E6 ECM connector.

1. Measure the resistance of the wire harness side connectors.

   Standard resistance:

     Tester Connection | Specified Condition
     A18-1 (HT) - E16-2 (HA1A) | Below 1 Ω
     A18-3 (AF+) - E16-22 (A1A+) | Below 1 Ω
     A18-4 (AF-) - E16-30 (A1A-) | Below 1 Ω
     A25-1 (HT) - E16-1 (HA2A) | Below 1 Ω
     A25-3 (AF+) - E16-23 (A2A+) | Below 1 Ω
     A25-4 (AF-) - E16-31 (A2A-) | Below 1 Ω
     A18-1 (HT) or E16-2 (HA1A) - Body ground | 10 kΩ or higher
     A18-3 (AF+) or E16-22 (A1A+) - Body ground | 10 kΩ or higher
     A18-4 (AF-) or E16-30 (A1A-) - Body ground | 10 kΩ or higher
     A25-1 (HT) or E16-1 (HA2A) - Body ground | 10 kΩ or higher
     A25-3 (AF+) or E16-23 (A2A+) - Body ground | 10 kΩ or higher
     A25-4 (AF-) or E16-31 (A2A-) - Body ground | 10 kΩ or higher

| NG |

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK |

4.PERFORM CONFIRMATION DRIVING PATTERN

NEXT |

5.CHECK WHETHER OUTPUT DTC RECURS (P2A00 OR P2A03)

1. Connect the intelligent tester to the DLC3.

1. Turn the ignition switch ON and turn the tester ON.

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

1. Read DTCs.

   Result:

     Display | Proceed to
     DTC P2A00 and/or P2A03 are not output | A
     DTC P2A00 and/or P2A03 are output | B

| B |

CHECK FOR INTERMITTENT PROBLEMS

A |

6.REPLACE AIR FUEL RATIO SENSOR

NEXT |

7.PERFORM CONFIRMATION DRIVING PATTERN

NEXT |

8.CHECK WHETHER DTC OUTPUT RECURS (P2A00 OR P2A03)

1. Connect the intelligent tester to the DLC3.

1. Turn the ignition switch ON and turn the tester ON.

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

1. Read DTCs.

   Result:

     Display | Proceed to
     DTC P2A00 and/or P2A03 are not output | A
     DTC P2A00 and/or P2A03 are output | B

| A |

CHECK AIR FUEL RATIO EXTREMELY LEAN OR RICH

B |

END