GSIC - Global Service Information Center

### DTC P0135/21 Oxygen (A/F) Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)

## for Preparation Click here

## DESCRIPTION

Refer to DTC P0130/21 (Click here).

DTC No. | DTC Detection Condition | Trouble Area

P0135/21

Open or short in heater circuit of oxygen sensor for 0.5 seconds or more

1. Open or short in heater circuit of oxygen sensor
2. Heated oxygen sensor
3. ECM

HINT:

  Sensor 1 refers to the sensor closer to the engine assembly.

## WIRING DIAGRAM

Refer to DTC P0130/21 (Click here).

## INSPECTION PROCEDURE

HINT:

  Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions 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.

1.INSPECT HEATED OXYGEN SENSOR

1. Disconnect the H6 sensor connector.

1. Measure the resistance of the sensor.

   Standard resistance:

     Tester Connection | Condition | Specified Condition
     1 (HT) - 2 (+B) | 20°C (68°F) | 5 to 10 Ω
     1 (HT) - 4 (E) | - | 10 kΩ or higher

| NG |

REPLACE HEATED OXYGEN SENSOR

OK |

2.CHECK WIRE HARNESS (+B VOLTAGE)

1. Disconnect the H6 heated oxygen sensor connector.

1. Turn the ignition switch ON.

1. Measure the voltage of the wire harness side connector.

   Standard voltage:

     Tester Connection | Specified Condition
     H6-2 (+B) - Body ground | 9 to 14 V

| OK |

Go to step 4

NG |

3.INSPECT INTEGRATION RELAY (MAIN RELAY)

1. Remove the integration relay from the engine room junction block (Click here).

1. Measure the voltage of the MAIN relay.

   Standard voltage:

     Tester Connection | Condition | Specified Condition
     1J-5 - Body ground | Ignition switch ON | 10 to 14 V

| NG |

REPLACE INTEGRATION RELAY

OK |

4.CHECK WIRE HARNESS (HEATED OXYGEN SENSOR - ECM, MAIN RELAY)

1. Disconnect the H6 sensor connector.

1. Disconnect the E12 ECM connector.

1. Disconnect the 1J connector from the engine room junction block (Click here).

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

   Standard resistance:

     Tester Connection | Specified Condition
     H6-1 - E12-1 (HT1A) | Below 1 Ω
     H6-2 (+B) - 1J-5 | Below 1 Ω
     H6-1 or E12-1 (HT1A) - Body ground | 10 kΩ or higher
     H6-2 (+B) or 1J-5 - Body ground | 10 kΩ or higher

| NG |

REPAIR OR REPLACE HARNESS AND CONNECTOR

OK |

5.CHECK IF DTC OUTPUT RECURS

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 the DTCs.

   Result:

     Display (DTC output) | Proceed to
     No output | A
     Heated oxygen sensor circuit DTCs | B

| B |

REPLACE ECM

A |

CHECK FOR INTERMITTENT PROBLEMS