How To Test The EVRV Solenoid (1988-1995 4.3L TBI Chevrolet S10 Pickup, GMC S15 Pickup, GMC Sonoma)

TEST 6: Energizing The EVRV Solenoid

In this test section, we'll verify that the fuel injection computer is able to command the EVRV solenoid ON.

We can easily achieve this by bridging (jumpering) the A and B connectors of the DLC connector (see illustration 2 of 2 in the image viewer above).

Once these two terminals are connected together, we'll check that the EVRV solenoid is allowing vacuum to flow from its inlet port to its outlet port.

NOTE: The DLC connector is also known as the ALDL connector in GM tech speak (ALDL = Assembly Line Data Link)

Let's get going:

1. 1

   Connect your vacuum pump to the EVRV solenoid's vacuum inlet port.

2. 2

   Disconnect the vacuum line that connects to the EGR valve.

3. 3

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

4. 4

   Jumper data link connector (DLC) terminals A and B
   
   Jumpering the A and B terminals of the DLC connector will cause the fuel injection computer to energize the EVRV solenoid.

5. 5

   Apply vacuum to the EVRV solenoid with the vacuum pump.

6. 6

   The vacuum hose that connects to the EGR valve should have vacuum while you pump the vacuum pump.

Let's interpret your test result:

CASE 1: The EVRV solenoid allowed vacuum to flow to the EGR valve. This is the correct test result and it confirms that the fuel injection computer is able to activate the EVRV solenoid.

Up to this point, all of the tests you've performed indicate that the EVRV solenoid is functioning correctly (not faulty).

CASE 2: The EVRV solenoid DID NOT allow vacuum to flow to the EGR valve. This usually means that the EVRV solenoid is bad, but we need to perform one more test to make sure. Go to: TEST 7: Making Sure The EVRV Solenoid Is Getting An Activation Signal.

TEST 7: Making Sure The EVRV Solenoid Is Getting An Activation Signal

In this last test section, we're gonna make sure that the activation signal from the fuel injection computer is actually present in the connector.

You'll need a 12 Volt automotive test light for this test procedure.

These are the test steps:

1. 1

   Disconnect the EVRV solenoid from its pigtail connector.

2. 2

   Connect the 12 Volt test light across terminals A and B of the EVRV solenoid's connector.

3. 3

   Have your helper turn the key to the ON position but don't crank or start the engine.

4. 4

   Jumper data link connector (DLC) terminals A and B
   
   Jumpering the A and B terminals of the DLC connector will cause the fuel injection computer to energize the EVRV solenoid.

5. 5

   The 12 Volt test light should come on.

Let's analyze your test result:

CASE 1: The 12 Volt test light came on. This is the correct and expected test result and it tells you that the EVRV solenoid is receiving an activation signal from the fuel injection computer.

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 (TEST 2).
• Confirmed the EVRV solenoid is getting Ground (TEST 3).
• Confirmed the EVRV solenoid is not stuck open (TEST 4 and TEST 5).
• Confirmed the EVRV solenoid is not allowing vacuum to flow to the EGR valve when activated (TEST 6).
• In this test section, confirmed that the EVRV solenoid is receiving an activation signal from the fuel injection computer.

CASE 2: The 12 Volt test light DID NOT come on. This test result tells you that the EVRV solenoid is not receiving an activation signal from the fuel injection computer.

Without this activation signal, the EVRV solenoid will not function and the fuel injection computer will register a trouble code 32 and illuminate the check engine light.

The most likely cause of this missing activation signal is:

• An open-circuit problem in the GRY wire between the EVRV solenoid connector and the fuel injection computer connector.
• The fuel injection computer is bad (very rare).