How To Test The EGR Valve (1996-1998 2.2L Chevrolet S10, GMC Sonoma)

TEST 4: Making Sure The EGR Valve Pintle Position Sensor Is Receiving Ground

Making Sure The EGR Valve Pintle Position Sensor Is Receiving Ground. How To Test The EGR Valve (1998, 1999, 2000 2.2L Chevrolet S10, GMC Sonoma, And Isuzu Hombre)

So far, your EGR valve diagnostic tests have confirmed that:

  • The EGR valve pintle position signal is stuck in one value (TEST 2).
  • Terminal D is supplying 5 Volts to the EGR valve's pintle position sensor (TEST 3).

The next step is to make sure that the EGR valve's pintle position sensor is receiving Ground when you turn the key to the ON position.

The wire that delivers this Ground is the black (BLK) wire of the EGR valve's connector.

The BLK wire connects to the terminal labeled with the letter B in the illustration above.

CAUTION: Ground is provided internally by the PCM. So be careful and don't short this terminal (circuit) to battery 12 Volts, or you'll fry the PCM. The multimeter voltage test suggested in the instructions below is a safe way to check for the presence of Ground in this circuit.

These are the test steps:

  1. 1

    Place your multimeter in Volts DC mode.

  2. 2

    Disconnect the EGR valve from its pigtail connector.

  3. 3

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

  4. 4

    Gently probe the female terminal labeled with the letter B with black 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 10 to 12 Volts DC.

Let's interpret your test results:

CASE 1: The multimeter registered 10 to 12 Volts. This is the correct and expected test result and confirms the EGR valve pintle position sensor is receiving Ground.

You can conclude that the EGR valve is bad and needs replacement if you have:

  • Confirmed the EGR valve pintle position signal is stuck in one value as you opened/closed the pintle (TEST 2).
  • Confirmed the EGR valve pintle position sensor is receiving 5 Volts (TEST 3).
  • Confirmed the EGR valve pintle position sensor is receiving Ground (this test section).

CASE 2: The multimeter DID NOT register 10 to 12 Volts. This test result confirms the EGR valve pintle position sensor is not receiving Ground. Without it, the EGR valve's pintle position sensor will not be able to create its position signal.

Although it's beyond the scope of this tutorial, your next step is to find out why Ground missing and restore it.

TEST 5: Making Sure The EGR Solenoid Is Getting Ground

Making Sure The EGR Solenoid Is Getting Ground. How To Test The EGR Valve (1998, 1999, 2000 2.2L Chevrolet S10, GMC Sonoma, And Isuzu Hombre)

The EGR valve has an internal solenoid that opens/closes its pintle to allow/shut off exhaust gas flow.

To accomplish this task, the EGR valve's solenoid needs 12 Volts and Ground.

The focus of this test section is to check that the terminal labeled with the letter A is connecting the solenoid to Ground.

The wire that connects to terminal A is the black with white stripe (BLK/WHT) wire of the EGR valve's 5-wire connector.

NOTE: The Ground that the BLK/WHT wire provides is a chassis Ground and is available at all times.

These are the test steps:

  1. 1

    Place your multimeter in Volts DC mode.

  2. 2

    Disconnect the EGR valve from its pigtail connector.

  3. 3

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

  4. 4

    Gently probe the female terminal labeled with the letter A with the black multimeter test lead.

  5. 5

    The multimeter should read 10 to 12 Volts DC.

    NOTE: No need to turn the key to the ON position since this is a chassis Ground and is provided at all times.

Let's interpret your test results:

CASE 1: The multimeter registered 10 to 12 Volts. This is the correct and expected test result and confirms the EGR valve solenoid is receiving Ground.

Your next step is checking the solenoid's resistance. Go to: TEST 6: EGR Solenoid Resistance Test.

CASE 2: The multimeter DID NOT register 10 to 12 Volts. This test result confirms the EGR valve solenoid is not receiving Ground. Without it, the EGR valve solenoid can not move the pintle (up/down).

The most likely cause of this missing Ground is an open-circuit problem in the BLK/WHT wire. Although it's beyond the scope of this tutorial, your next step is to find out why Ground is missing and restore it.

Chevrolet Vehicles:

  • S10 Pickup 2.2L
    • 1998, 1999, 2000

GMC Vehicles:

  • Sonoma 2.2L
    • 1998, 1999, 2000

Isuzu Vehicles:

  • Hombre 2.2L
    • 1998, 1999, 2000