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

TEST 2: Verifying MAP Sensor Has 5 Volts And Ground

Usually when you get a MAP signal voltage stuck in one value it means that the MAP sensor itself is bad.

In some cases this test result is usually due to the fact that the MAP sensor isn't getting power or Ground.

So in this last test section we're going to make sure that the MAP sensor is getting power (5 Volts DC) and Ground from your 2.2L Chevy Malibu (Classic) or 2.2L Pontiac Grand Am's fuel injection computer.

IMPORTANT: Since the MAP sensor gets Ground from your 2.2L Chevrolet Malibu (Classic) or Pontiac Grand Am's fuel injection computer you need to be careful not to short-circuit the Ground wire to 12 Volts (battery power). Or you're going to fry the fuel injection computer. The multimeter voltage test I'm outlining in the test instructions below is a safe way to test for Ground.

These are the test steps:

1. 1

   Place your multimeter in Volts DC mode and turn the key on but don't start the engine.

2. 2

   Verify that the GRY wire has voltage (4.5 to 5 Volts DC) with the key on but engine off.
   
   Connect the red multimeter test lead (using the appropriate tool) to the GRY wire. Connect the black multimeter test lead to the negative battery terminal.
   
   Your multimeter should read 4.5 to 5 Volts DC.

3. 3

   Verify that the ORG/BLK wire has Ground with the key on but engine off.
   
   Connect the black multimeter test lead (using the appropriate tool) to the ORG/BLK wire. Connect the red multimeter test lead to the positive battery terminal.
   
   Your multimeter should read 12 Volts DC.

These are what the test results mean:

CASE 1: The multimeter confirms that the MAP sensor is being fed power and Ground. This is the correct test result.

You can conclude that the manifold absolute pressure (MAP) sensor is defective only if you have:

• Verified that the MAP sensor is not creating a voltage signal that decreases/increases as you apply/release vacuum to it.
• The MAP sensor is getting both 5 Volts and Ground.

If you need to buy the MAP sensor, check my MAP sensor recommendations here: Where To Buy The MAP Sensor And Save.

CASE 2: Multimeter confirms that the MAP sensor IS NOT being fed 5 Volts. Without these 5 Volts the MAP sensor will not function.

The most likely cause of these missing 5 Volts is an open-circuit problem in the wire (that feeds this voltage to the MAP sensor).

CASE 3: Multimeter confirms that the MAP sensor IS NOT being fed Ground. Without this Ground the MAP sensor will not function.

The most likely cause of this missing Ground is an open-circuit problem in the wire (that feeds this Ground to the MAP sensor).

More GM 2.2L Test Tutorials

If this tutorial was helpful, be sure and take a look at all of the 2.2L GM test tutorials in this index:

• GM 2.2L Index Of Articles.