GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Other than checking for a worn grommet and loose electrical connectors, the only service possible is a unit replacement if the diagnosis shows a malfunctioning manifold absolute pressure (MAP) sensor.

    Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  1. Disconnect the negative battery cable.

  2. Object Number: 421253  Size: SH
  3. Disconnect the MAP sensor harness connector.
  4. Notice: Do not rotate or pry on the MAP sensor when removing. Damage to the MAP sensor or the intake manifold may result.


    Object Number: 421259  Size: SH

    Important: If the original MAP sensor is to be reused after removing the MAP sensor from the intake manifold, replace the MAP sensor to intake manifold grommet.

  5. Remove the MAP sensor by pulling straight up with a slight rocking motion.
  6. Remove the MAP sensor grommet.
  7. Discard the MAP sensor grommet.

Installation Procedure


    Object Number: 421259  Size: SH
  1. Install a new MAP sensor grommet on the MAP sensor.
  2. Install the MAP sensor.

  3. Object Number: 421253  Size: SH
  4. Connect the MAP sensor harness connector.
  5. Connect the negative battery cable.