H3 2006

Manifold Absolute Pressure Sensor

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Location



Specific to:

Hummer H3 2006-2010

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

Operation



Specific to:

Hummer H3 2006-2010

The Manifold Absolute Pressure (MAP) Sensor is a piezoelectric (pressure-sensitive) electronic device that monitors the intake manifold vacuum and atmospheric pressure. The MAP Sensor operates within a 5 volt DC reference range, and provides a linear input signal to the Powertrain Control Module (PCM) that is based upon a comparison of air density and intake manifold vacuum under measured operating conditions. The PCM uses data from the MAP Sensor to calculate air-fuel mixture, ignition timing, and fuel injector pulse width.

Removal & Installation



3.5L & 3.7L Engines

Specific to:

Hummer H3 2006-2010

  1. Disconnect the Manifold Absolute Pressure (MAP) sensor electrical connector.
  2.  
  3. Press the retainer locking tabs inward, then pull the retainer up to remove.

    Click image to see an enlarged view

    Fig. Press the retainer locking tabs inward, then pull the retainer(1) up to remove, remove the MAP sensor (2) from the intake manifold (3)

  4.  
  5. Remove the MAP sensor from the intake manifold.
  6.  
  7. Inspect the MAP sensor seal for damage, and replace as necessary.
  8.  

To install:

  1. Lightly lubricate the MAP sensor seal with clean engine oil, to aid in installation.
  2.  
  3. Install the MAP sensor into the intake manifold.
  4.  
  5. Install the MAP sensor retainer.
  6.  
  7. Connect the MAP sensor electrical connector.
  8.  

5.3L Engine

Specific to:

Hummer H3 2006-2010

  1. Remove the upper intake manifold cover.
  2.  
  3. Disconnect the engine wiring harness electrical connector from the Manifold Absolute Pressure (MAP) sensor.
  4.  
  5. Remove the MAP sensor retainer from the intake manifold.
  6.  
  7. Remove the MAP sensor from the intake manifold.

    Click image to see an enlarged view

    Fig. MAP sensor location-5.3L engine

  8.  

To install:


NOTE
Lightly coat the MAP sensor seal with clean engine oil before installing the sensor.

  1. Install the MAP sensor into the intake manifold.
  2.  
  3. Install the MAP sensor retainer to the intake manifold.
  4.  
  5. Connect the engine wiring harness electrical connector to the MAP sensor.
  6.  
  7. Install the upper intake manifold cover.
  8.  

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.  

MAP Circuit Testing

Specific to:

Hummer H3 2006-2010

Use a suitable scan tool, a Graphing Multi-Meter (GMM), or a Digital Volt-Ohm Meter (DVOM) in order to view the MAP data.

MAP Sensor logic is relative to the scale of resistance: when the manifold absolute pressure is low, the voltage is decreased. When the coolant temperature is high, the voltage is increased.

Inspect the air intake tube, the engine air filter, and the MAP sensor for contamination and physical damage in order to verify that the air induction system is in proper working order. If an air induction system fault is evident, repair as required before continuing.

If a DVOM is being used, additional information may be acquired by taking measurements at the sensor connector as well as the PCM connector. If a significant voltage drop is measured (greater than 0.5 volts DC), check the wiring harness and connections for corrosion, poor pin connections, or damaged wires.

If all engine wiring and pin connections are confirmed, disconnect the MAP Sensor to verify the signal with a DVOM, and verify PCM communication before replacing the MAP Sensor.

Click image to see an enlarged view

Fig. MAP Sensor Range Chart

MAP Sensor Strategy

Specific to:

Hummer H3 2006-2010

The MAP Sensor provides a linear input signal to the Powertrain Control Module (PCM) for a number of engine control system calculations. The MAP signal is compared with Mass Air Flow (MAF), Intake Air Temperature (IAT), and Fuel Trim (HO2S) in order to determine the correct air-fuel mixture for measured operating conditions.

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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