Testing the MAP sensor on the 2007 and 2008 3.5L Chevy Malibu is a piece of cake, especially because the MAP sensor sits right on top of the intake manifold and is easy to get to.
In this tutorial, I'll explain how to test it using a multimeter and a vacuum pump.
Contents of this tutorial:
You can find this tutorial in Spanish here: Cómo Probar El Sensor MAP (2007-2008 3.5L Chevrolet Malibu) (at: autotecnico-online.com).
NOTE: You can find the MAP sensor test for the 2004-2006 3.5L Chevrolet Malibu here: How To Test The MAP Sensor (2004-2006 3.5L Malibu).
Symptoms Of A Bad MAP Sensor
The MAP sensor on your 2007-2008 3.5L Chevy Malibu is a key component of the engine management system.
Its job is to measure the amount of vacuum inside the intake manifold so that the fuel injection computer can calculate engine load.
Being that it's a critical component of the fuel injection system, when it fails the PCM is going to light up the check engine light with one or more of the following MAP sensor trouble codes:
- P0107: Manifold absolute pressure (MAP) sensor circuit low voltage.
- P0108: Manifold absolute pressure (map) sensor circuit high voltage.
- P1106: Manifold absolute pressure (map) sensor circuit intermittent high voltage.
- P1107: Manifold absolute pressure (map) sensor circuit intermittent low voltage.
Besides having the check engine light illuminated by a MAP sensor trouble code, you're also going to see one or more of the following symptoms:
- Extended cranking time. In other words the engine takes longer than usual to start.
- Black smoke coming out of the tailpipe.
- Once the engine starts, the engine idles rough and may even stall.
- The engine does not start.
- Lack of power when accelerating the engine under load.
- Bad gas mileage.
MAP Sensor Connector Pinout
The MAP sensor connector above applies only to the 2007-2008 3.5L Chevrolet Malibu.
Gray (GRY) wire (1): 5 Volts DC input. This voltage is provided by your Chevy Malibu's fuel injection computer.
Orange with black stripe (ORG/BLK) wire (2): Ground input. This Ground is provided by your Chevy Malibu's fuel injection computer.
Light green (LT GRN) wire (3): MAP signal output to the fuel injection computer.
Where To Buy The MAP Sensor And Save
The MAP sensor on your 2007-2008 3.5L Chevrolet Malibu is not an expensive engine management component. You can find this bad boy in just about any auto parts store. The following links will help you to comparison-shop and hopefully save you a few bucks (I've also added the MAP sensor connector link):
2007 MAP Sensor:
2008 MAP Sensor:
TEST 1: MAP Sensor Signal Voltage Test
The thing to know about the MAP sensor is that when it's not getting vacuum, it's MAP voltage signal is around 4 to 4.5 Volts DC.
Once vacuum is applied to it, the MAP signal voltage decreases. The more vacuum is applied to it, smaller the voltage output.
Knowing this will help us to diagnose the MAP sensor's performance since we're going to manually apply vacuum to it and see the voltage it is creating.
If the MAP sensor on your 2007 - 2008 3.5 Chevy Malibu is defective, then its signal voltage will stay stuck at a specific value no matter how much vacuum you apply to it with your vacuum pump.
IMPORTANT: The MAP sensor must remain connected to its electrical connector while you perform the test described in this section (or the test won't work). To read the MAP signal inside the wire you'll need to use a back probe on the connector or a wire piercing probe on the wire. You can see an example of this tool here: Wire Piercing Probe Review (Power Probe PWPPPPP01).
These are the test steps:
- 1
Remove the MAP sensor from the intake manifold .
Reconnect the MAP sensor back to its electrical connector if you disconnected it to remove it. - 2
Place your multimeter in Volts DC mode.
- 3
With the red multimeter test lead probe the gray (GRY) wire of the MAP sensor connector.
- 4
Ground the black multimeter test lead directly on the battery negative (-) terminal.
- 5
Connect your vacuum pump to the MAP sensor's vacuum inlet nipple.
- 6
Turn the key on but don't crank or start the engine .
The MAP sensor voltage should be around 4.4 to 4.8 Volts without applying vacuum to the sensor. - 7
Apply vacuum to the MAP sensor with the vacuum pump.
The MAP sensor's voltage signal should decrease as you apply vacuum. - 8
Release the vacuum you applied to the MAP sensor with the vacuum pump.
The MAP sensor's voltage signal should increase back to the value you noticed in step 6.
Let's examine your test results:
CASE 1: The MAP signal voltage decreased/increased as you applied/released vacuum. This is the correct and expected test result. With this result you can conclude that the MAP sensor, on your 3.5L Chevy Malibu, is in good working condition.
You can also skip the next two tests because this test result let you know that the MAP sensor is getting both power and Ground.
CASE 2: The MAP signal voltage did not decrease/increase as you applied/released vacuum. This test result generally tells you that the MAP sensor is defective.
To be absolutely sure that your Chevy Malibu MAP sensor is bad, we need to make sure that it's getting power and Ground. Go to: TEST 2: Making Sure The MAP Sensor Is Getting Power.
