Escalade, Suburban 1500 & 2500, Tahoe, Yukon, Yukon XL 1500 & 2500 (2006-2007), Yukon Denali and Yukon Denali XL (2005-2006)

Manifold Absolute Pressure Sensor

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Operation



Using the pressure and temperature data, the PCM calculates the intake air mass. It is connected to the engine intake manifold and takes readings of the absolute pressure.

Atmospheric pressure is measured both when the engine is started and when driving fully loaded, then the pressure sensor information is adjusted accordingly.

Removal & Installation



  1. Detach the electrical connection from the MAP sensor.
  2.  
  3. Remove the screws securing the sensor, then remove it from the intake manifold.
  4.  
  5. Installation is the reverse of removal. If reusing the sensor, replace the seal.

    Click image to see an enlarged view

    Fig. MAP sensor mounting

  6.  

Testing



  1. Turn ON the ignition, with the engine OFF, and remove the MAP sensor.
  2.  
  3. Install a 3 amp fused jumper wire between the 5-volt reference circuit and the corresponding terminal of the MAP sensor.
  4.  
  5. Install a jumper wire between the low reference circuit of the MAP sensor and ground.
  6.  
  7. Install a jumper wire at the MAP sensor signal circuit.
  8.  
  9. Connect a digital multimeter between the jumper wire from the MAP sensor signal circuit and ground.
  10.  
  11. Install hand vacuum pump to the MAP sensor vacuum port. Slowly apply vacuum to the sensor while observing the voltage on the multimeter. The voltage should vary between 0-5.2 volts without any spikes or dropouts.
  12.  
  13. If the voltage is not within the specified range or is erratic, replace the MAP sensor.
  14.  

 
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