H3 2006

Heated Oxygen Sensor

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Component Description



Specific to:

Hummer H3 2006-2010

The Oxygen Sensor is a zirconium dioxide electronic device that measures the proportion of oxygen (O2) content in the exhaust gas. The sensor operates by measuring the difference between the oxygen content in the exhaust gas and the external air, and generates a variable voltage signal as the ratio between the two changes. The function of the oxygen sensor is to monitor the air-fuel ratio of the engine, determine if the mixture is rich or lean, and provide feedback (real-time information) to the Powertrain Control Module (PCM) so that the air-fuel ratio may be automatically adjusted.

Location



Specific to:

Hummer H3 2006-2010

Refer to the graphics in the Removal and Installation section for the location(s).

Operation



Fuel Trim

Specific to:

Hummer H3 2006-2010

Fuel trim is the PCM parameter that is used to adjust the air-fuel mixture. The ideal HO2S feedback value is 0.45 volts DC, which is indicated when air and fuel are at the stoichiometric ratio of 14.7:1. This value is determined by oxygen sensor feedback, and provides the final data for the PCM in determining the correct air-fuel mixture.

Oxygen Sensor Heater

Specific to:

Hummer H3 2006-2010

In order to achieve operating temperature and enter closed loop more quickly, modern oxygen sensors have built-in heating elements.

Removal & Installation



Specific to:

Hummer H3 2006-2010


CAUTION
Be careful of the following:



Do not remove the pigtail from either the heated oxygen sensor (HO2S) or the oxygen sensor (O2S).
 
Removing the pigtail or the connector will affect sensor operation.
 
Handle the oxygen sensor carefully. Do not drop the HO2S. Keep the in-line electrical connector and the louvered end free of grease, dirt, or other contaminants. Do not use cleaning solvents of any type.
 
Do not repair the wiring, connector or terminals. Replace the oxygen sensor if the pigtail wiring, connector, or terminal is damaged.
 
This external clean air reference is obtained by way of the oxygen sensor signal and heater wires. Any attempt to repair the wires, connectors, or terminals could result in the obstruction of the air reference and degraded sensor performance.
 


CAUTION
The following guidelines should be used when servicing the heated oxygen sensor:



Do not apply contact cleaner or other materials to the sensor or vehicle harness connectors. These materials may get into the sensor causing poor performance.
 
Do not damage the sensor pigtail and harness wires in such a way that the wires inside are exposed. This could provide a path for foreign materials to enter the sensor and cause performance problems.
 
Ensure the sensor or vehicle lead wires are not bent sharply or kinked. Sharp bends or kinks could block the reference air path through the lead wire.
 
Do not remove or defeat the oxygen sensor ground wire, where applicable. Vehicles that utilize the ground wired sensor may rely on this ground as the only ground contact to the sensor. Removal of the ground wire will cause poor engine performance.
 
Ensure that the peripheral seal remains intact on the vehicle harness connector in order to prevent damage due to water intrusion. The engine harness may be repaired using Packard's Crimp and Splice Seals Terminal Repair Kit. Under no circumstances should repairs be soldered since this could result in the air reference being obstructed.
 

3.5L & 3.7L Engines

NOTE
When replacing the HO2S perform the following:




  1. A code clear with a scan tool, regardless of whether or not a DTC is set
  2.  
  3. HO2S heater resistance learn reset with a scan tool, where available
    NOTE
    Perform the above in order to reset the HO2S resistance learned value and avoid possible HO2S failure.

  4.  

HO2S Sensor 1

Specific to:

Hummer H3 2006-2010

  1. Remove the right front fender wheelhouse panel.
  2.  
  3. Disconnect the Heated Oxygen Sensor (HO2S) electrical connector from the following:

    The engine wiring harness electrical connector
     
    The camshaft cover

    Click image to see an enlarged view

    Fig. Disconnect the Heated Oxygen Sensor (HO2S) electrical connector

     

  4.  
  5. Using the J 39194-B remove the HO2S from the exhaust manifold.

    Click image to see an enlarged view

    Fig. Using the J 39194-B remove the HO2S from the exhaust manifold

  6.  

To install:


NOTE
Use special anti-seize compound on the HO2S threads. The compound consists of graphite suspended in fluid and glass beads. The graphite burns away, but the glass beads remain, making the sensor easier to remove. New service sensors already have the compound applied to the threads. If you remove an oxygen sensor and if for any reason you must install the same oxygen sensor, apply the anti-seize compound to the threads before reinstallation.

  1. Coat the threads of the HO2S with the anti-seize compound P/N 5613695, or equivalent if necessary.
  2.  
  3. Using the J 39194-B, install the HO2S into the exhaust manifold. Tighten the HO2S to 31 ft. lbs. (42 Nm).
  4.  
  5. Connect the HO2S electrical connector to the following:

    The engine wiring harness electrical connector
     
    The camshaft cover
     

  6.  
  7. Install the right front fender wheelhouse panel.
  8.  

HO2S Sensor 2

Specific to:

Hummer H3 2006-2010

  1. Raise and support the vehicle.
  2.  
  3. Disconnect the Heated Oxygen Sensor (HO2S) electrical connector from the engine wiring harness connector.

    Click image to see an enlarged view

    Fig. Disconnect the heated oxygen sensor (HO2S) electrical connector (3) from the engine wiring harness (2) connector (1)

  4.  
  5. Using the J 39194-B, remove the HO2S from the catalytic converter.

    Click image to see an enlarged view

    Fig. Using the J 39194-B, remove the HO2S (1) from the catalytic converter

  6.  

To install:


NOTE
Use special anti-seize compound on the HO2S threads. The compound consists of graphite suspended in fluid and glass beads. The graphite burns away, but the glass beads remain, making the sensor easier to remove. New or service sensors already have the compound applied to the threads. If you remove an oxygen sensor and if for any reason you must reinstall the same oxygen sensor, apply the anti-seize compound to the threads before reinstallation.

  1. Coat the threads of the HO2S with the anti-seize compound P/N 5613695, or equivalent if necessary.
  2.  
  3. Using the J 39194-B, install the HO2S into the catalytic converter. Tighten the HO2S to 31 FT. LBS. (42 Nm).
  4.  
  5. Connect the HO2S electrical connector to the engine wiring harness connector.
  6.  
  7. Lower the vehicle.
  8.  

5.3L Engine
Bank 1, Sensor 1

Specific to:

Hummer H3 2006-2010

  1. Raise and suitably support the vehicle.
  2.  
  3. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector.

    Click image to see an enlarged view

    Fig. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector

  4.  
  5. Remove the HO2S wiring from under the rear HO2S electrical connector.
  6.  
  7. Remove the HO2S.

    Click image to see an enlarged view

    Fig. Remove the HO2S (1)

  8.  

To install:


NOTE
A special anti-seize compound is used on the HO2S threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away, but the glass beads remain, making the sensor easier to remove. New, or service replacement sensors already have the compound applied to the threads. If the sensor is removed from an exhaust component and if for any reason the sensor is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

  1. If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
    NOTE
    Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

  2.  
  3. Install the HO2S. Tighten the sensor to 31 ft. lbs. (42 Nm).
  4.  
  5. Route the HO2S wiring under the rear HO2S electrical connector.
  6.  
  7. Connect the HO2S electrical connector to the engine wiring harness electrical connector.
  8.  
  9. Lower the vehicle.
  10.  

Bank 1, Sensor 2

Specific to:

Hummer H3 2006-2010

  1. Raise and suitably support the vehicle.
  2.  
  3. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector.

    Click image to see an enlarged view

    Fig. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector

  4.  
  5. Remove the HO2S wiring from under the rear HO2S electrical connector.
  6.  
  7. Remove the HO2S.

    Click image to see an enlarged view

    Fig. Remove the HO2S (2)

  8.  

To install:


NOTE
A special anti-seize compound is used on the HO2S threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away, but the glass beads remain, making the sensor easier to remove. New, or service replacement sensors already have the compound applied to the threads. If the sensor is removed from an exhaust component and if for any reason the sensor is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

  1. If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
    NOTE
    Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

  2.  
  3. Install the HO2S. Tighten the sensor to 31 ft. lbs. (42 Nm).
  4.  
  5. Route the HO2S wiring under the rear HO2S electrical connector.
  6.  
  7. Connect the HO2S electrical connector to the engine wiring harness electrical connector.
  8.  
  9. Lower the vehicle.
  10.  

Bank 2 Sensor 1

Specific to:

Hummer H3 2006-2010

  1. Raise and suitably support the vehicle.
  2.  
  3. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector.

    Click image to see an enlarged view

    Fig. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector

  4.  
  5. Remove the HO2S wiring from under the rear HO2S electrical connector.
  6.  
  7. Remove the HO2S.

    Click image to see an enlarged view

    Fig. Remove the HO2S (1)

  8.  

To install:


NOTE
A special anti-seize compound is used on the HO2S threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away, but the glass beads remain, making the sensor easier to remove. New, or service replacement sensors already have the compound applied to the threads. If the sensor is removed from an exhaust component and if for any reason the sensor is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

  1. If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
    NOTE
    Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

  2.  
  3. Install the HO2S. Tighten the sensor to 31 ft. lbs. (42 Nm).
  4.  
  5. Route the HO2S wiring under the rear HO2S electrical connector.
  6.  
  7. Connect the HO2S electrical connector to the engine wiring harness electrical connector.
  8.  
  9. Lower the vehicle.
  10.  

Bank 2 Sensor 2

Specific to:

Hummer H3 2006-2010

  1. Raise and suitably support the vehicle.
  2.  
  3. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector.

    Click image to see an enlarged view

    Fig. Disconnect the HO2S electrical connector from the engine wiring harness electrical connector

  4.  
  5. Remove the HO2S wiring from under the rear HO2S electrical connector.
  6.  
  7. Remove the HO2S.

    Click image to see an enlarged view

    Fig. Remove the HO2S (2)

  8.  

To install:


NOTE
A special anti-seize compound is used on the HO2S threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away, but the glass beads remain, making the sensor easier to remove. New, or service replacement sensors already have the compound applied to the threads. If the sensor is removed from an exhaust component and if for any reason the sensor is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

  1. If reinstalling the old sensor, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
    NOTE
    Replacement components must be the correct part number for the application. Components requiring the use of the thread locking compound, lubricants, corrosion inhibitors, or sealants are identified in the service procedure. Some replacement components may come with these coatings already applied. Do not use these coatings on components unless specified. These coatings can affect the final torque, which may affect the operation of the component. Use the correct torque specification when installing components in order to avoid damage.

  2.  
  3. Install the HO2S. Tighten the sensor to 31 ft. lbs. (42 Nm).
  4.  
  5. Route the HO2S wiring under the rear HO2S electrical connector.
  6.  
  7. Connect the HO2S electrical connector to the engine wiring harness electrical connector.
  8.  
  9. Lower the vehicle.
  10.  

Testing



Specific to:

Hummer H3 2006-2010


NOTE
Refer to the Electrical Wiring Diagram for component and connector locations, connector views, and circuit-specific information.

Connection & Wiring Diagnosis

Specific to:

Hummer H3 2006-2010

Refer to the Electrical Wiring Diagram for component and connector locations, connector views, and circuit-specific information.

Many intermittent open or short circuits may be caused by wiring harness and connector movement due to vibration, engine torque, bumps and rough pavement, etc.

  1. Test the wiring harness and connectors by performing the following tests:

    Move the related connectors and wiring while monitoring the appropriate scan tool data.
     
    Move the related connectors and wiring with the component commanded ON and OFF. Using a suitable the scan tool, observe the component operation.
     
    With the engine running, move the related connectors and wiring while monitoring component operation.
     
    If harness or connector movement affects the data displayed, the component and system operation, or the engine operation, inspect and repair the harness or connections as necessary.
     

  2.  
  3. Test the connector terminal pins and/or wiring by performing the following tests:

    Inspect for incorrect mating of the connector halves, or terminals not fully seated in the connector body.
     
    Inspect for improperly formed or damaged terminals and test for incorrect terminal tension.
     
    Inspect for poor terminal to wire connections including terminals crimped over insulation. This requires removing the terminal from the connector body.
     
    Inspect for corrosion or water intrusion. Pierced or damaged insulation can allow moisture to enter the wiring. The conductor can corrode inside the insulation with little visible evidence. Look for swollen and/or brittle sections of wire in the suspect circuits.
     
    Inspect for wires that are broken inside the insulation by gently pulling on suspect sections of wiring.
     

  4.  

Heated Oxygen Sensor Strategy

Specific to:

Hummer H3 2006-2010

The oxygen sensor operates most effectively when an operating temperature of 1,472° F (800° C) or higher is reached and maintained. When the oxygen sensor reaches the specified temperature and begins sending the feedback signal, the PCM uses the information to enter closed loop mode, which is defined as the PCM having full control of the air-fuel ratio. In order to achieve operating temperature and enter closed loop more quickly, modern oxygen sensors have built-in heating elements.

Oxygen Sensor Heater

Specific to:

Hummer H3 2006-2010

The oxygen sensor heater may be tested by performing a resistance test; the sensor must be disconnected from the main engine wiring harness. If the circuit resistance is greater than 5.0 ohms, replace the HO2S. Refer to the Electrical Wiring Diagram for specific circuit information and connector views.

Click image to see an enlarged view

Fig. Normal pre-catalyst HO2S reading



Click image to see an enlarged view

Fig. Normal post-catalyst HO2S reading

Post-Catalyst Sensor 2

Specific to:

Hummer H3 2006-2010

A properly operating #2, or rear heated oxygen sensor (HO2S) should display flat feedback voltage of less than 0.2 volts DC . Use a suitable scan tool or a Graphing Multi-Meter (GMM) in order to view HO2S data.

If the feedback signal displays a cross-count, this is usually an indication of a faulty catalytic converter. If the feedback signal is flat, but is greater than 0.5 volts DC, additional diagnosis is required in order to determine the proper function of the HO2S, or if a fault exists in any related sub-systems.

Pre-Catalyst Sensor 1

Specific to:

Hummer H3 2006-2010

A properly operating #1, or front heated oxygen sensor (HO2S) should display a cross count of eight oscillations or more within ten seconds, within a voltage range of 0.2 - 0.8 volts Cause a suitable scan tool or a Graphing Multi-Meter (GMM) in order to view HO2S data.

If the feedback signal is not within the specified range, additional diagnosis is required in order to determine the proper function of the HO2S, or if a fault exists in any related sub-systems.

Related Diagnostic Trouble Codes

Specific to:

Hummer H3 2006-2010



Click image to see an enlarged view

Fig. Related Diagnostic Trouble Codes

 
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