How To Test The MAP Sensor (2004, 2005 2.2L Chevrolet Classic, 2004, 2005, 2006 2.2L Chevrolet Malibu, And 2002, 2003, 2004, 2005 2.2L Pontiac Grand Am)

Testing the manifold absolute pressure (MAP) sensor on the 2004-2005 2.2L Chevrolet Classic, the 2004-2006 2.2L Chevrolet Malibu or the 2002-2005 2.2L Pontiac Grand Am can be easily done with just a simple multimeter.

In this tutorial I'll explain how to test it so that you can find out if it's defective or not.

NOTE: This tutorial applies to the following vehicles (since they use the exact same MAP sensor):

  1. 2004, 2005 2.2L Chevrolet Classic.
  2. 2004, 2005, 2006 2.2L Chevrolet Malibu.
  3. 2002, 2003, 2004, 2005 2.2L Pontiac Grand Am.

Puedes encontrar este tutorial en Español aquí: Cómo Probar El Sensor MAP (2004-2006 2.2L Chevrolet Malibu y 2002-2005 Pontiac Grand Am) (en: autotecnico-online.com).

Symptoms Of A Bad MAP Sensor

MAP Sensor Pin Out. How To Test The MAP Sensor (2004, 2005 2.2L Chevrolet Classic, 2004, 2005, 2006 2.2L Chevrolet Malibu, And 2002, 2003, 2004, 2005 2.2L Pontiac Grand Am)

The MAP sensor's job is to let your 2.2L Chevrolet Malibu (Classic) or 2.2L Pontiac Grand Am's fuel injection computer know how much vacuum pressure exists in the intake manifold when the engine is running.

It uses this information for a few things but mainly to calculate the engine's load.

Being that it's a critical component of the engine management system, when it fails you're going to see one of the following symptoms:

  1. Check engine light (CEL) is shining nice and bright on the instrument cluster.
  2. DTC P0107 MAP sensor Circuit Low Voltage.
  3. DTC P0108 MAP sensor Circuit High Voltage.
  4. Rough idle.
  5. ‘Rotten egg’ smell coming from the exhaust.
  6. Won't pass the state mandated emissions test.
  7. Bad gas mileage.
  8. Lack of power, rough idle, or hesitation.
  9. Engine cranks a long time before starting.

The MAP sensor is a 3 wire type sensor. This means that it has a power wire, a Ground wire and a signal wire. The table below has a brief description of each:

Terminal Wire Description
A ORG/BLK Ground
B LT GRN MAP Signal
C GRY 5 Volts

TEST 1: Testing The MAP Sensor Voltage Signal

Testing The MAP sensor Voltage Signal. How To Test The MAP Sensor (2004, 2005 2.2L Chevrolet Classic, 2004, 2005, 2006 2.2L Chevrolet Malibu, And 2002, 2003, 2004, 2005 2.2L Pontiac Grand Am)

For our very first test we are going to connect our multimeter to the middle wire of the MAP sensor.

This wire is wire that takes the MAP sensor signal to the fuel injection computer.

We're then going to apply vacuum to the MAP sensor so that we can monitor the MAP sensor signal on our multimeter.

As vacuum is being applied to the MAP sensor, it's a voltage signal should decrease. Once we release the vacuum be applied to it, the voltage signal should increase back to the original voltage value noticed at the beginning of the test.

If the MAP sensor is defective the signal voltage will stay stuck in one value as we manually apply vacuum to it.

IMPORTANT: The MAP sensor must remain connected to its electrical connector for this test to work. To access the voltage inside the wire you'll need to use a back probe or a wire piercing probe. You can see an example of this tool here: Wire Piercing Probe.

NOTE: If you don't have a vacuum pump to apply vacuum to the manifold absolute pressure (MAP) sensor -don't worry. You can use your mouth to apply vacuum to it.

Let's get started:

  1. 1

    Remove the MAP sensor from the intake manifold.

  2. 2

    Connect your vacuum pump to the MAP sensor's vacuum inlet port. Reconnect the MAP sensor to its connector if you disconnected it.

  3. 3

    Set your multimeter's selector to Volts DC mode.

  4. 4

    Connect the red test lead to the LT GRN wire of the MAP sensor's connector. This wire is identified by the letter B in the photo above.

    Remember, the MAP sensor must remain connected to its 3 wire connector.

  5. 5

    Ground the black multimeter test lead directly on the battery negative (-) terminal.

  6. 6

    Turn the Key on but don't start the engine. This will power up the MAP sensor and you should see a reading of 4.7 Volts DC on your multimeter.

  7. 7

    Now, apply vacuum to the MAP sensor with the vacuum pump (or your mouth). The voltage signal value should decrease.

    If you're using a vacuum pump: At 5 in.Hg → 3.9 Volts. At 10 in.Hg → 3 Volts. At 15 in.Hg → 2.1 Volts. At 20 in.Hg → 1.2 Volts.

  8. 8

    Release the vacuum. Once released, your multimeter should show the original voltage value.

    Repeat this test step several times making sure that each time the voltage decreases/increases as you apply/release vacuum.

Let's take a look at what your test results mean:

CASE 1: The MAP voltage signal decreased and increased as you applied and released vacuum. This test result lets you know that the MAP sensor is working correctly and thus is not defective.

With this test result you can also conclude that the MAP sensor is getting both power (5 Volts) and Ground from your 2.2L Chevy Malibu (Classic) or 2.2L Pontiac Grand Am's fuel injection computer.

CASE 2: The MAP voltage signal DID NOT decrease/increase as you applied/released vacuum. This test result usually indicates that the MAP sensor is defective but not always.

The next test is to make sure that the MAP sensor is getting 5 Volts and Ground from your 2.2L Malibu (Classic) or Grand Am's fuel injection computer. If the MAP sensor is getting power and Ground, then you can conclude that it's defective. For these tests go to: TEST 2: Verifying MAP Sensor Has 5 Volts And Ground.

CASE 3: Multimeter DID NOT register any voltage. This test result usually indicates that the MAP sensor is defective but not always.

The next test is to make sure that the MAP sensor is getting 5 Volts and Ground from your 2.2L Malibu (Classic) or Grand Am's fuel injection computer. If the MAP sensor is getting power and Ground, then you can conclude that it's defective. For these tests go to: TEST 2: Verifying MAP Sensor Has 5 Volts And Ground.