Heated Oxygen Sensor (HO2S)

Specifications

Specification

HO2S [Bank 1 / Sensor 1]

Item	Specification
Heater Resistance (Ω)	2,5–4,0 [20 °C]
Type	Linear
Pin	6

HO2S [Bank 1 / Sensor 2]

Item	Specification
Heater Resistance (Ω)	Approximately 9.0 [20 °C]
Type	Binary
Pin	4

Description and Operation

Description

Installed both upstream and downstream of the manifold catalytic converter, the Heated Oxygen Sensor (HO2S) consists of zirconia and alumina. The output voltage of the sensor changes according to the air-fuel ratio. The sensor must be heated to operate properly. To keep it hot, it is equipped with a heater controlled by the ECM through a duty cycle signal. When the exhaust gas temperature is below the specified value, the heater heats the sensor tip.

Circuit Diagrams

Wiring Diagram

[A/T]

[M/T]

Repair Procedures

Inspection

1. 1
   Turn the ignition off.
2. 2
   Disconnect the HO2S connector.
3. 3
   Measure the resistance between terminals 2 and 5 [B1/S1] of the HO2S.

   Specification: 2.4–4.0 [20 °C]

4. 4
   Measure the resistance between terminals 3 and 4 [B1/S2] of the HO2S.

   Specification: Approximately 9.0 [20 °C]

5. 5
   Make sure the resistance is within specification.

Removal

[Bank 1/Sensor 1]

1. 1
   Turn the ignition switch OFF and disconnect the negative (-) battery terminal.
2. 2
   Disconnect the connector (A).
3. 3
   Remove the heated oxygen sensor (B). Heated Oxygen Sensor: 39.2–49 N·m

   

[Bank 1/Sensor 2]

1. 1
   Turn the ignition switch OFF and disconnect the negative (-) battery terminal.
2. 2
   Disconnect the connector (A).

   

3. 3
   Remove the heated oxygen sensor (A). Heated Oxygen Sensor: 39.2–49 N·m

   

Installation

1. Install in the reverse order of removal.