TEST 2: Verifying The MAF Sensor Is Getting Power

How To Test The MAF Sensor (2.5L Grand Vitara -2.5L Chevy Tracker)

Before we condemn the MAF sensor as bad (if it didn't pass TEST 1) we need to make sure that it's getting power. Power is in the form of battery voltage.

The wire that delivers power to the MAF sensor is the blue with black stripe (BLU/BLK) wire (of the MAF sensor engine wiring harness MAF sensor connector).

To check for this voltage, we'll do a simple multimeter voltage test. These are the steps:

NOTE: The connector in the illustration above is the connector on the MAF sensor itself and NOT the engine wiring harness MAF connector.

  1. 1

    With your multimeter still in Volts DC mode from the previous test and the key on (but engine off).

  2. 2

    Probe the BLU/BLK) wire of the MAF sensor connector. This is the wire that connects to MAF sensor pin 3 in the illustration above.

    You can test for these 12 Volts with the MAF sensor's electrical connector connected to the MAF sensor or not, just avoid probing the front of the connector.

  3. 3

    Now Ground the black multimeter test lead on the battery's negative post.

  4. 4

    If the BLU/BLK wire has power, your multimeter will register 10 to 12 Volts DC.

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

CASE 1: The BLU/BLK wire, of the MAF sensor connector, has 10 to 12 Volts DC: This is the correct test result.

Now that you have confirmed that the MAF sensor is getting power, the next step is to check that it's getting Ground. Go to: TEST 3: Verifying The MAF Is Getting Ground.

CASE 2: The BLU/BLK wire, of the MAF sensor connector, DOES NOT have 10 to 12 Volts DC: This results lets you know that the MAF sensor is not bad, since without these 12 Volts DC, the MAF sensor can not function.

Although it's beyond the scope of this article to troubleshoot the cause of these missing 12 Volts, you have now eliminated the MAF sensor as bad. Resolving the issue that is keeping these 12 Volts from being supplied will solve the MAF sensor issue on your 2.5L Grand Vitara (or 2.5L Chevrolet Tracker).

TEST 3: Verifying The MAF Sensor Is Getting Ground

How To Test The MAF Sensor (2.5L Grand Vitara -2.5L Chevy Tracker)

Up to this point, your tests have:

  1. Confirmed a MAF sensor code is lighting up the check engine light (P0101, P0102, or P0103).
  2. Confirmed that the MAF sensor's voltage signal is stuck in one voltage value (TEST 1).
  3. Confirmed the MAF sensor is getting power on the BLU/BLK wire.

Now you need to make sure that the gray with yellow stripe (GRY/YEL) wire of the MAF sensor electrical connector is feeding the MAF sensor with ground.

Testing for Ground is done with another simple multimeter voltage test.

NOTE: The connector in the illustration above is the connector on the MAF sensor itself and NOT the engine wiring harness MAF connector.

IMPORTANT: Be careful that you don't intentionally or accidentally short the GRY/YEL wire to battery power or you'll fry your Suzuki Grand Vitara's PCM. Checking for Ground by doing a voltage test with a multimeter, as described in the test steps below, is a safe way to test this circuit.

These are the steps:

  1. 1

    With your multimeter still in Volts DC mode from the previous test and the Key On (but engine Off).

  2. 2

    Probe the GRY/YEL wire with the black multimeter test lead.

    NOTE: It doesn't matter if you probe this circuit (wire) with the connector connected to the MAF sensor or not, but do not probe the front of the connector (if you decide to unplug the connector to test for this path to Ground).

  3. 3

    Now connect the red multimeter test lead on the battery's positive (+) Post.

  4. 4

    If the GRY/YEL wire has Ground, then your multimeter will register 10 to 12 Volts DC.

OK, let's take a look at what your results mean:

CASE 1: The multimeter confirms that the GRY/YEL wire is feeding Ground to the MAF sensor: This is the correct test result and confirms that the MAF sensor is bad and needs to be replaced.

Here's why: So far you verified:

  1. That the MAF sensor is not producing the correct signal voltage values when you accelerate/decelerate the engine (TEST 1).
  2. That it is being fed with power (TEST 2).
  3. That the MAF sensor does have a solid path to Ground (TEST 3).

These test results, interpreted together, indicate that the MAF sensor is bad.

CASE 2: The multimeter confirms that the GRY/YEL wire IS NOT feeding Ground to the MAF sensor: double check your multimeter connections and repeat the test... if your multimeter results still do not indicate 12 Volts, then the mass air flow (MAF) sensor is not fried and not the cause of the MAF sensor diagnostic trouble code (DTC) issue.

Here's why: Without a good path to Ground, that the PCM provides internally, the MAF sensor will not work. With this test result, you have eliminated the MAF sensor as bad.

Suzuki Vehicles:

  • Grand Vitara 2.5L V6
    • 1999, 2000, 2001, 2002, 2003, 2004, 2005

Chevrolet Vehicles:

  • Tracker 2.5L V6
    • 2001, 2002, 2003, 2004