How To Test The MAP Sensor (2008-2012 2.4L Chevrolet Malibu)

TEST 2: Verifying MAP Sensor Has 5 Volts And Ground

If you've reached this point then the MAP sensor did not pass TEST 1. In some cases the MAP sensor doesn't create a decreasing/increasing voltage signal because it's not receiving either 5 Volts or Ground.

So what we're going to do in this test section is to make sure that the MAP sensor is getting 5 Volts and Ground from its electrical connector.

5 Volts are provided by the gray (GRY) wire of the MAP sensor's electrical connector.

Ground is provided by the orange with black stripe (ORG/BLK) wire of the MAP sensor's electrical connector.

IMPORTANT: Ground is provided by the fuel injection computer to the MAP sensor. So be careful not to pass 12 Volts (battery power) to the Ground wire of the MAP sensor's electrical connector or you will fry the computer. The multimeter voltage test I'm suggesting in the test instructions below is a safe way of checking for the presence of Ground in the orange with black stripe wire.

These are the test steps:

1. 1

   Place your multimeter in Volts DC mode.

2. 2

   Turn the key the ON position but don't start the engine.

3. 3

   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.

4. 4

   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 MAP sensor is getting 5 Volts and Ground. This is the correct and expected test result.

You can conclude that the MAP sensor is defective, on your 2.4L Chevrolet Malibu (Pontiac G6), if you have confirmed that:

• The MAP sensor is not creating a decreasing/increasing voltage signal when you apply/release vacuum to it (TEST 1).
• The MAP sensor is getting 5 Volts DC and Ground from the fuel injection computer.

CASE 2: The MAP sensor IS NOT getting 5 Volts. These missing 5 Volts will cause the MAP sensor to not work.

The most likely cause of these missing 5 Volts is an open-circuit problem in the gray wire of the MAP sensor's electrical connector.

Although it's beyond the scope of this tutorial to troubleshoot these missing 5 Volts, you have eliminated the MAP sensor itself as the cause of the MAP sensor trouble code lighting up the check engine light on your 2.4L Chevrolet Malibu (Pontiac G6).

CASE 3: The MAP sensor IS NOT getting Ground. This Ground will cause the MAP sensor to not work.

The most likely cause of this missing Ground is an open-circuit problem in the pink with black stripe wire of the MAP sensor's electrical connector.

Although it's beyond the scope of this tutorial to troubleshoot this missing Ground, you have eliminated the MAP sensor itself as the cause of the MAP sensor trouble code lighting up the check engine light on your 2.4L Chevrolet Malibu (Pontiac G6).