How To Test The EVRV Solenoid (1988-1993 2.8L Chevrolet S10, GMC S15 Pickup, GMC Sonoma)

TEST 4: Is The EVRV Solenoid Stuck Open? PART 1

Is The EGR Vacuum Solenoid Stuck Open? How To Test The EGR Vacuum Solenoid (1988, 1989, 1990, 1991, 1992, 1993 2.8L V6 Chevrolet S10 Pickup, GMC S15 Pickup, And GMC Sonoma)

In this test section section, we'll check if the EVRV solenoid is stuck open and allowing vacuum to flow from its vacuum port 2 to its vacuum port 1 while disconnected from its electrical connector.

If vacuum is flowing from one port to the other, you can conclude that the EVRV solenoid is defective and needs to be replaced.

If no vacuum flows from one port to the other, we can move on to the next test.

Let's get testing:

  1. 1

    Disconnect the EVRV solenoid from its electrical connector.

  2. 2

    Disconnect the vacuum line that connects to the EGR valve.

    NOTE: Leave the other end of the vacuum line connected to the EVRV solenoid.

  3. 3

    Disconnect the vacuum line that connects to the EVRV solenoid port labeled with the number 2 in the photo above.

  4. 4

    Connect a vacuum pump to the EVRV solenoid port 2.

  5. 5

    Apply vacuum to the EVRV solenoid with the vacuum pump.

  6. 6

    The vacuum hose that connects to the EGR valve should NOT have vacuum while applying a vacuum with the vacuum pump.

    NOTE: The vacuum line you're checking for vacuum is the one you disconnected in step 2.

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

CASE 1: The EVRV solenoid is allowing vacuum to flow to the EGR valve. This test result tells you that the EVRV solenoid is stuck open.

You can conclude that the EVRV solenoid is bad and needs replacement if you have:

  • Confirmed the EVRV solenoid is getting vacuum (TEST 1).
  • Confirmed the EVRV solenoid is getting 12 Volts and Ground (TEST 2 and TEST 3).
  • Confirmed in this test section that the EVRV solenoid is stuck open.

CASE 2: The EVRV solenoid IS NOT allowing vacuum to flow to the EGR valve. This is the correct test result.

The next step is to perform this same test but with the EVRV solenoid connected to its electrical connector. Go to: TEST 5: Is The EVRV Solenoid Stuck Open? PART 2.

TEST 5: Is The EVRV Solenoid Stuck Open? PART 2

Is The EGR Vacuum Solenoid Stuck Open? How To Test The EGR Vacuum Solenoid (1988, 1989, 1990, 1991, 1992, 1993 2.8L V6 Chevrolet S10 Pickup, GMC S15 Pickup, And GMC Sonoma)

In the previous test step, we checked to see if the EVRV solenoid was stuck open with its electrical connected disconnected.

In this test section, we'll repeat the same test but with the EVRV solenoid connected to its electrical connector.

Let's get testing:

  1. 1

    Reconnect the EVRV solenoid to its electrical connector.

  2. 2

    Disconnect the vacuum line that connects to the EGR valve.

    NOTE: Leave the other end of the vacuum line connected to the EVRV solenoid.

  3. 3

    Disconnect the vacuum line that connects to the EVRV solenoid valve port marked with number 2 in the photo above.

  4. 4

    Connect a vacuum pump to the EVRV solenoid port 2.

  5. 5

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

  6. 6

    Apply vacuum to the EVRV solenoid with the vacuum pump.

  7. 7

    The vacuum hose that connects to the EGR valve should NOT have vacuum while applying a vacuum with the vacuum pump.

    NOTE: The vacuum line you're checking for vacuum is the one you disconnected in step 2.

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

CASE 1: The EVRV solenoid is allowing vacuum to flow to the EGR valve. This test result tells you that the EVRV solenoid is open (ON) and it should not be.

The most likely cause of this problem is:

  • The gray (GRY) wire has a short-to-Ground problem.
  • The fuel injection computer has failed (very rare).

Although it's beyond the scope of this tutorial, your next step is to check the continuity of the GRY wire between the EVRV solenoid connector and the fuel injection computer connector.

CASE 2: The EVRV solenoid IS NOT allowing vacuum to flow to the EGR valve. This is the correct and expected test result.

Your next step is to go to: TEST 6: Energizing The EVRV Solenoid.

Chevrolet Vehicles:

  • S10 Pickup 2.8L
    • 1988, 1989, 1990, 1991 1992, 1993

GMC Vehicles:

  • S15 Pickup 2.8L
    • 1988, 1989, 1990
  • Sonoma 2.8L
    • 1991, 1992, 1993
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