How To Test The GM MAF Sensor Express And Savana Van (2003-2008)

TEST 2: Testing The Power Circuit For 12 Volts

Like any other electrical/electronic component on your Savana van (or Express van), the MAF sensor needs power (in the form of 12 Volts) to work. So, the first test is to verify that it is getting power.

You can use a 12 Volt test light or a multimeter to test for power, although the test steps assume you're using a multimeter.

By the way, I recommend that you test the circuit with the connector connected to the mass air flow (MAF) sensor and using a wire Piercing Probe (or any other appropriate tool) to pierce the wire (to get to the signal). Probing the front of the terminal, to get to the 12 Volt signal, could lead to some major complications.

OK, nuff said, here's the test:

1. 1

   Place the multimeter in Volts DC mode.

2. 2

   Disconnect the MAF sensor from its electrical connector.

3. 3

   With the red multimeter test lead, probe the female terminal that connects to the PNK wire identified with the number 4.

4. 4

   Connect the black multimeter test lead to the battery negative (-) terminal.

5. 5

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

6. 6

   The multimeter should register between 10 to 12 Volts DC.

Let's interpret your test results:

CASE 1: The multimeter registered 10 to 12 Volts DC (or the if the test light came on), then this indicates that the MAF sensor is getting juice (12 Volts). The next step is to verify that it's also getting a good Ground, go to: TEST 3: Testing The Ground Circuit.

CASE 2: The multimeter DID NOT register 10 to 12 Volts DC (or the if the test light DID NOT come on), this exonerates the MAF sensor as being bad, since without 12 Volts, the MAF sensor will not work and this will light up the check engine light (CEL) on your instrument cluster. Repairing the cause of the missing voltage will solve the problem.

TEST 3: Testing The Ground Circuit

So far, you know that the MAF sensor has power. Now you need to test that it has a good path to Ground and in this test, you'll find out if it does or not.

These are the test steps:

1. 1

   Place the multimeter in Volts DC mode.

2. 2

   Disconnect the MAF sensor from its electrical connector.

3. 3

   With the black multimeter test lead, probe the female terminal that connects to the BLK (or BLK/WHT) wire identified with the number 3.

4. 4

   Connect the red multimeter test lead to the battery positive (+) terminal.

5. 5

   The multimeter should register between 10 to 12 Volts DC.

Let's find out what your test results mean:

CASE 1: The multimeter registered 10 to 12 Volts DC. This test result indicates that the MAF sensor is getting Ground.

You can conclude that the MAF sensor is bad and needs to be replaced if you have:

• Confirmed that the MAF sensor's output signal is stuck in one value (TEST 1).
• Confirmed that the MAF sensor is getting power (TEST 2).
• Confirmed that the MAF sensor is getting Ground (this test section).

CASE 2: The multimeter DID NOT register 10 to 12 Volts DC (or the if the test light DID NOT come on). This exonerates the MAF sensor as being bad, since without a good Ground, the MAF sensor will not work.

Repairing the cause of the missing Ground will solve the MAF sensor problem.