How To Test The EGR Valve (1996-2001 4.3L V6 Chevrolet S10 Pickup, GMC Sonoma)

TEST 2: EGR Pintle Position Sensor Performance Test

When the EGR valve is energized and its pintle opens to allow exhaust gas into the intake manifold, the pintle position voltage signal increases.

When the EGR valve receives the command to close, the pintle position voltage signal decreases.

Generally, if the pintle position sensor fails, its output voltage value will remain stuck at one voltage value as the pintle opens/closes.

In this test section, we'll check if the pintle position signal increases/decreases using a multimeter and by physically pushing and releasing the pintle into the valve.

CAUTION: The EGR valve has to be removed from the engine to perform this test. If the engine has been running for any length of time, let it cool down. The EGR valve can get very hot! Take all safety precautions to avoid burning your fingers or hands.

Let's get going:

  1. 1

    Remove the EGR valve from its place on the engine.

    IMPORTANT: Reconnect the EGR valve to its electrical connector if you had to disconnect it before continuing to the next step.

  2. 2

    Place your multimeter in DC Volts mode.

  3. 3

    Connect the red multimeter test lead to the wire that connects to the female terminal labeled with the letter C.

  4. 4

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

  5. 5

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

  6. 6

    Your multimeter should register 0.6 to 0.9 Volts DC at this point.

  7. 7

    With a small screw-driver push the EGR pintle up and into the EGR valve.

  8. 8

    The multimeter should display an increasing voltage reading as you push the EGR pintle up into the EGR valve.

    The maximum attainable voltage, with the EGR valve's pintle fully pressed into the EGR valve, will be about 4.5 Volts DC.

  9. 9

    Release the EGR valve's pintle back to its fully seated position.

  10. 10

    The voltage reading should return to the value you recorded in step 6.

  11. 11

    Repeat steps 7 thru 9 several times to make sure of your test result.

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

CASE 1: The voltage increased/decreased as you pushed/released the EGR pintle. This is the correct test result and tells you the EGR valve's pintle position sensor is working correctly.

You can also conclude that the EGR valve pintle position sensor is getting 5 Volts and Ground from the PCM.

The next step is to ensure that the EGR valve solenoid is getting power. Go to: TEST 5: Making Sure The EGR Solenoid Is Getting 12 Volts.

CASE 2: The voltage DID NOT increase/decrease as you pushed/released the EGR pintle. It's not looking good for the EGR valve, but we still need to make sure the EGR valve pintle position sensor is getting 5 Volts and Ground.

For the first of the next two tests, go to: TEST 3: Making Sure The EGR Valve Pintle Position Sensor Is Receiving 5 Volts.

TEST 3: Making Sure The EGR Valve Pintle Position Sensor Is Receiving 5 Volts

Making Sure The EGR Valve Pintle Position Sensor Is Receiving 5 Volts. How To Test The EGR Valve (1996, 1997, 1998, 1999, 2000, 2001 4.3L Chevrolet S10 Pickup, GMC Sonoma, And Isuzu Hombre)

The pintle position sensor gets 5 Volts DC and Ground from the fuel injection computer. Without 5 Volts and Ground, the sensor does not generate a pintle position voltage signal.

In this section of testing, we'll focus on making sure the pintle position sensor is getting 5 Volts DC at the terminal labeled with the letter D (see image above).

We check that terminal D is providing 5 Volts with the multimeter in Volts DC mode.

If terminal D is supplying 5 Volts to the pintle position sensor, the next step is to make sure it is receiving Ground.

Let's get the ball rolling:

  1. 1

    Place your multimeter in Volts DC mode.

  2. 2

    Disconnect the EGR valve from its pigtail connector.

  3. 3

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

  4. 4

    Gently probe the female terminal labeled with the letter D with the red multimeter test lead.

  5. 5

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

  6. 6

    The multimeter should read 4.5 to 5 Volts.

Let's interpret your test results:

CASE 1: The multimeter registered 5 Volts. This is the correct and expected test result.

Now that you've confirmed that the EGR valve is receiving 5 Volts, your next step is to see if its getting Ground. For this test, go to: TEST 4: Making Sure The EGR Valve Pintle Position Sensor Is Receiving Ground.

CASE 2: The multimeter DID NOT register 5 Volts. Without these 5 Volts, the EGR valve's pintle position sensor will not function.

Although it's beyond the scope of this tutorial, your next step is to find out why these 5 Volts are missing and restore them.

Chevrolet Vehicles:

  • S10 Pickup 4.3L
    • 1996, 1997, 1998, 1999, 2000, 2001

GMC Vehicles:

  • Sonoma 4.3L
    • 1996, 1997, 1998, 1999, 2000, 2001

Isuzu Vehicles:

  • Hombre 4.3L
    • 1998, 1999, 2000