Aura, Outlook 2007

Heated Oxygen Sensor

Print

Operation



Heated oxygen sensors (HO2S) are used for fuel control and post catalyst monitoring. Each HO2S compares the oxygen content of the surrounding air with the oxygen content in the exhaust stream. The HO2S must reach operating temperature to provide an accurate voltage signal. A heating element inside the HO2S minimizes the time required for the sensor to reach operating temperature. Voltage is provided to the heater by an ignition voltage circuit through a fuse. With the engine running, ground is provided to the heater by the HO2S heater low control circuit, through a low side driver within the Engine Control Module (ECM). The ECM uses pulse width modulation (PWM) to control the HO2S heater operation to maintain a specific HO2S operating temperature range.

Removal & Installation



2.4L Engine
Sensor 1

NOTE
The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor. Also the use of excessive force may damage the threads in the exhaust manifold/pipe.


NOTE
The in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the Heated Oxygen sensor (HO2S).

  1. Remove the Connector Position Assurance (CPA) retainer.
  2.  
  3. Disconnect the engine wiring harness electrical connector from the HO2S electrical connector.
  4.  
  5. Remove the HO2S connector clip from the thermostat housing tab.
  6.  
  7. Remove the HO2S.
  8.  

To install:


NOTE
A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.

  1. Installation is the reverse of removal, tighten the sensor to 31 ft. lbs. (42 Nm).
  2.  

Sensor 2

NOTE
The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor. Also the use of excessive force may damage the threads in the exhaust manifold/pipe.


NOTE
The in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the Heated Oxygen sensor (HO2S).

  1. Raise and safely support the vehicle.
  2.  
  3. Remove the Connector Position Assurance (CPA) retainer.
  4.  
  5. Disconnect the engine wiring harness electrical connector from the HO2S electrical connector.
  6.  
  7. Remove the HO2S connector clip from the thermostat housing tab.
  8.  
  9. Remove the HO2S.
  10.  

To install:


NOTE
A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.

  1. Installation is the reverse of removal, tighten the sensor to 31 ft. lbs. (42 Nm).
  2.  

3.5L Engine
Bank 1 Sensor 1
  1. Remove the intake manifold cover.
  2.  
  3. Remove the Connector Position Assurance (CPA) retainer.
  4.  
  5. Disconnect the engine wiring harness electrical connector from the Heated Oxygen sensor (HO2S) electrical connector.
  6.  
  7. Remove the HO2S electrical connector rosebud clip from the ignition coil bracket.
    NOTE
    The oxygen sensor may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage threads in the exhaust manifold or the exhaust pipe.

  8.  
  9. Remove the HO2S.
  10.  

To install:


NOTE
A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.

  1. Installation is the reverse of removal, tighten the sensor to 31 ft. lbs. (42 Nm).
  2.  

Bank 1 Sensor 2
  1. Raise and support the vehicle.
  2.  
  3. Remove the Connector Position Assurance (CPA) retainer.
  4.  
  5. Disconnect the engine Heated Oxygen sensor (HO2S) electrical connector from the engine wiring harness electrical connector.
    NOTE
    The oxygen sensor may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage threads in the exhaust manifold or the exhaust pipe.

  6.  
  7. Remove the HO2S.
  8.  

To install:


NOTE
A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.

  1. Installation is the reverse of removal, tighten the sensor to 31 ft. lbs. (42 Nm).
  2.  

Bank 2 Sensor 1
  1. Remove the Connector Position Assurance (CPA) retainer.
  2.  
  3. Disconnect the engine wiring harness electrical connector from the Heated Oxygen sensor (HO2S) electrical connector.
  4.  
  5. Remove the HO2S rosebud clip from the oil level indicator tube tab.
    NOTE
    The oxygen sensor may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage threads in the exhaust manifold or the exhaust pipe.

  6.  
  7. Remove the HO2S
  8.  

To install:


NOTE
A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.

  1. Installation is the reverse of removal, tighten the sensor to 31 ft. lbs. (42 Nm).
  2.  

Bank 2 Sensor 2
  1. Raise and support the vehicle.
  2.  
  3. Remove the Connector Position Assurance (CPA) retainer.
  4.  
  5. Disconnect the Heated Oxygen sensor (HO2S) electrical connector from the engine wiring harness electrical connector.
    NOTE
    The oxygen sensor may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage threads in the exhaust manifold or the exhaust pipe.

  6.  
  7. Remove the HO2S
  8.  

To install:


NOTE
A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.

  1. Installation is the reverse of removal, tighten the sensor to 31 ft. lbs. (42 Nm).
  2.  

3.6L Engine
Bank 1 Sensor 1
  1. Remove the fuel injector sight shield.
  2.  
  3. Remove the engine wiring harness Heated Oxygen sensor (HO2S) electrical connector clip from the engine harness.
  4.  
  5. Remove the Connector Position Assurance (CPA) retainer from the HO2S electrical connection.
  6.  
  7. Disconnect the engine wiring harness electrical connector from the HO2S electrical connector.
  8.  
  9. Raise and support the vehicle to an appropriate height to reach the HO2S.
  10.  
  11. Remove the HO2S from the exhaust manifold.
  12.  

To install:


NOTE
A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.

  1. Installation is the reverse of removal, tighten the sensor to 31 ft. lbs. (42 Nm).
  2.  

Bank 1 Sensor 2
  1. Raise and support the vehicle.
  2.  
  3. Remove the Connector Position Assurance (CPA) retainer from the Heated Oxygen sensor (HO2S) electrical connection.
  4.  
  5. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector.
  6.  
  7. Remove the bank 1 sensor 2 HO2S from the catalytic converter
  8.  

To install:


NOTE
A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.

  1. Installation is the reverse of removal, tighten the sensor to 31 ft. lbs. (42 Nm).
  2.  

Bank 2 Sensor 1
  1. Remove the fuel injector sight shield.
  2.  
  3. Remove the air cleaner outlet duct.
  4.  
  5. Remove the Connector Position Assurance (CPA) retainer from the Heated Oxygen sensor (HO2S) electrical connection.
  6.  
  7. Disconnect the engine wiring harness electrical connector from the HO2S electrical connector .
  8.  
  9. Remove the HO2S electrical connector clip from the engine wiring harness tab.
  10.  
  11. Remove the HO2S from the exhaust manifold.
  12.  

To install:


NOTE
A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.

  1. Installation is the reverse of removal, tighten the sensor to 31 ft. lbs. (42 Nm).
  2.  

Bank 2 Sensor 2
  1. Raise and support the vehicle.
  2.  
  3. Remove the Connector Position Assurance (CPA) retainer from the Heated Oxygen sensor (HO2S) electrical connection.
  4.  
  5. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector.
  6.  
  7. Remove the bank 2 sensor 2 HO2S from the catalytic converter.
  8.  

To install:


NOTE
A special anti-seize compound is used on the heated oxygen sensor threads. The compound consists of a liquid graphite and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.

  1. Installation is the reverse of removal, tighten the sensor to 31 ft. lbs. (42 Nm).
  2.  

Testing



2.4L Engine


Click image to see an enlarged view

Fig. Heated Oxygen sensor (HO2S) 1 terminals-2.4L engine (A) HO2S Low Signal Sensor 1 (B) HO2S High Signal Sensor 1 (C) HO2S Heater Low Control Sensor 1 (D) Ignition 1 Voltage



Click image to see an enlarged view

Fig. Heated Oxygen sensor (HO2S) 2 terminals-2.4L engine (A) HO2S Low Signal Sensor 2 (B) HO2S High Signal Sensor 2 (C) Not available (D) Ignition 1 Voltage (E) HO2S Heater Low Control Sensor 2

  1. Disconnect the sensor.
  2.  
  3. Turn the ignition ON, connect a test lamp between the HO2S heater voltage supply circuit terminal D and ground. The lamp should illuminate. If the lamp does not illuminate, test the voltage supply circuit for an open/high resistance or a short to ground. If the circuit tests normal and its fuse is open, replace the HO2S.
  4.  
  5. Turn the ignition OFF, connect a test lamp between the HO2S low control circuit terminal C and battery voltage. The lamp should not illuminate. If the lamp illuminates, test the low control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  6.  
  7. With the engine running, leave the test lamp connected from the previous step. The lamp should flash or be ON steady. If the test lamp is not on steady or flashing, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
    NOTE
    The output driver should detect a short to voltage and turn OFF. If a resistance fault is present, the driver will remain ON and the scan tool will display more than 0.0 amp. Less than 10 ohms of resistance may set a DTC. Performing this test may set additional DTCs

  8.  
  9. Turn the
  10.  
  11. Turn the ignition OFF, install a 30A fused jumper wire from the heater voltage supply circuit terminal D to the heater control circuit terminal C.
  12.  
  13. With the engine running, observe with a scan tool that the Heater parameter indicates 0.0A. If more than the specified value, test the heater voltage supply and control circuits for resistance greater than 3 ohms. If the circuits test normal, replace the ECM.
  14.  
  15. If the control module and all circuits test normal, replace the HO2S
  16.  

3.5L And 3.6L Engines
  1. Turn the ignition OFF, disconnect the harness connector at the appropriate HO2S.
  2.  
  3. Turn the ignition OFF, disconnect the harness connector at the appropriate HO2S. ON, verify that a test lamp illuminates between the appropriate HO2S heater voltage supply circuit terminal D and ground. If the test lamp does not illuminate, test the HO2S heater voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal and the HO2S heater voltage supply circuit fuse is open, test all components connected to the fuse and replace as necessary.
  4.  
  5. Turn the ignition ON, verify that a test lamp does not illuminate between the appropriate HO2S heater voltage supply circuit terminal D and the appropriate HO2S heater low control circuit terminal C. If the lamp illuminates, test the HO2S heater low control circuit for a short to ground.
  6.  
  7. If the circuit tests normal, replace the ECM.
  8.  
  9. With the engine running, leave the test lamp connected from the previous step. The lamp should flash or be ON steady. If the test lamp is not ON steady or flashing, test the HO2S heater low control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the ECM.
    NOTE
    The output driver should detect a short to voltage and turn OFF. If a resistance fault is present the driver will remain ON and the scan tool will display more than 0.0 amp. Less than 10 ohms of resistance may set a DTC.


    NOTE
    Performing this test may set additional DTCs.

  10.  
  11. Turn the ignition OFF, install a 30A fused jumper wire between the appropriate HO2S heater voltage supply circuit terminal D and the appropriate HO2S heater low control circuit terminal C.
  12.  
  13. With the engine running, verify the appropriate scan tool HO2S Heater parameter is less than 0.1 amp. f more than the specified range, test the HO2S heater voltage supply and HO2S heater low control circuits for more than 1 ohm of resistance. If the circuits test normal, replace the ECM.
  14.  
  15. If the ECM and all circuits test normal, replace the appropriate HO2S.

    Click image to see an enlarged view

    Fig. Heated Oxygen sensor (HO2S) sensor terminals bank 1 sensor 1-3.5L and 3.6L engines (A) HO2S Low Signal (Bank 1 Sensor 1) (B) HO2S High Signal (Bank 1 Sensor 1) (C) HO2S Heater Low Control (Bank 1 Sensor 1) (D) Ignition 1 Voltage



    Click image to see an enlarged view

    Fig. Heated Oxygen sensor (HO2S) sensor terminals bank 1 sensor 2-3.5L and 3.6L engines (A) HO2S Low Signal (Bank 1 Sensor 2) (B) HO2S High Signal (Bank 1 Sensor 2) (C) HO2S Heater Low Control (Bank 2 Sensor 1) (D) Ignition 1 Voltage



    Click image to see an enlarged view

    Fig. Heated Oxygen sensor (HO2S) sensor terminals bank 2 sensor 1-3.5L and 3.6L engines (A) HO2S Low Signal (Bank 2 Sensor 1) (B) HO2S High Signal (Bank 2 Sensor 1) (C) HO2S Heater Low Control (Bank 2 Sensor 1) (D) Ignition 1 Voltage



    Click image to see an enlarged view

    Fig. Heated Oxygen sensor (HO2S) sensor terminals bank 2 sensor 2-3.5L and 3.6L engines (A) HO2S Low Signal (Bank 2 Sensor 2) (B) HO2S High Signal (Bank 2 Sensor 2) (C) HO2S Heater Low Control (Bank 2 Sensor 2) (D) Ignition 1 Voltage

  16.  

 
label.common.footer.alt.autozoneLogo