How To Test The EVAP Purge Solenoid (2003-2007 Chevrolet Express, GMC Savana)

There's a super easy way I've been testing the EVAP purge solenoid that I'm gonna share with you in this tutorial. The best part of all is that you don't need any expensive diagnostic equipment to find out if it's good or bad.

In this tutorial, I'll show you how to test it in a step-by-step way. You'll easily find out if the EVAP purge solenoid is bad or not.

APPLIES TO: This tutorial applies to the following vehicles:

• Chevrolet Express 1500, 2500, 3500: 2003, 2004, 2005, 2006, 2007.
• GMC Savana 1500, 2500, 3500: 2003, 2004, 2005, 2006, 2007.

EVAP VENT SOLENOID: The following tutorial will help you test the EVAP vent solenoid:

• How To Test The EVAP Vent Solenoid (2003-2013 Chevrolet Express, GMC Savana)

Symptoms Of A Bad EVAP Purge Solenoid

When the EVAP purge solenoid goes bad, it often stays stuck in its closed position, which means the fuel vapors stored in the EVAP carbon canister stay put instead of being purged (sucked) into the intake manifold to be burned in the cylinders.

But here's the interesting thing: a faulty EVAP purge solenoid typically doesn't mess with how the engine performs or how the vehicle drives.

Generally you'll only see one or more of the following symptoms:

1. The check engine light will be illuminated by one of the following trouble codes:
   • P0443: EVAP System Purge Control Valve Circuit Malfunction.
2. Pressure in the gas tank when you remove the gas tank cap.
3. Your Express (Savana) van fails the emissions test.
4. Difficulty filling up the gas tank with fuel.

What Does The EVAP Purge Solenoid Do?

The canister purge solenoid is a crucial part of the evaporative emissions (EVAP) system in your V8 Chevrolet Express or GMC van.

The EVAP system's job is to keep the fuel vapors being produced in the gas tank from escaping into the environment. It does this by trapping those vapors in a carbon canister and then recycling them back into the engine to burn them as fuel.

The EVAP purge solenoid is the key component that gets those trapped fuel vapors back into the engine. It's the gatekeeper of the whole EVAP system. Most of the time, it's in the OFF position, keeping those fuel vapors locked up in the EVAP carbon canister, away from the intake manifold.

Sooner or later the fuel injection computer is gonna decide it's time to empty the carbon canister of its stored fuel vapors and will command the EVAP purge solenoid ON. In this ON state, the purge solenoid opens the gate and lets the fuel vapors flow into the intake manifold where they can be used as fuel by the engine.

Generally when the purge solenoid fails, it stays stuck in its closed position, which means the fuel vapors stay stuck in the canister instead of getting used by the engine like they should.

Where To Buy The EVAP Purge Solenoid

The AC-Delco brand is the original equipment (O.E.) part for your Chevrolet Express (GMC Savana). Dorman is another trusted brand.

The following links will help you comparison shop for the EVAP purge solenoid:

NOTE: Not sure if the EVAP purge solenoid fits your particular Express or Savana van? Don't worry. Once you get to the site, they'll ask you for the specifics of your van and make sure its the right one. If it isn't, they'll find you the right one.

What Tools Do I Need?

To test the EVAP purge solenoid, you'll need:

• A multimeter.
• Two jumper wires with insulated alligator clips.

The insulated alligator clips will help you avoid shorting the jumper wires together when connecting them to the male spade terminal of the EVAP purge solenoid when bench-testing it.

You'll need hand tools to remove the EVAP purge solenoid from its place underneath your Chevrolet Express (GMC Savana).

TEST 1: Making Sure That The EVAP Purge Solenoid Is Getting Power

To get our EVAP purge solenoid diagnostic started, we're gonna check if the EVAP purge solenoid is getting 10 to 12 Volts from it's 2-wire electrical connector.

This voltage is supplied by the pink (PNK) wire that connects to the female terminal labeled with the letter A in the illustration of the solenoid's 2-wire connector above.

We'll do a simple multimeter voltage test to check for the presence of these 10 to 12 Volts.

OK, let's start:

1. 1

   Disconnect the EVAP purge solenoid from its connector.

2. 2

   Place your multimeter in Volts DC mode.

3. 3

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

4. 4

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

5. 5

   With the red multimeter test lead, gently probe the terminal labeled with the letter A.
   
   Terminal A is the one that connects to the PNK wire.

6. 6

   The multimeter should register 10 to 12 Volts.

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

CASE 1: 10 to 12 Volts DC are present. This is the correct and expected test result.

The next step is to go to: TEST 2: Making Sure The EVAP Solenoid Is Blocking Fuel Vapor Intake.

CASE 2: The indicated voltage is not present. Without power, the EVAP purge solenoid will not function.

This is usually caused by one of two things:

• There's an open-circuit problem in the wiring between the EVAP purge solenoid's connector and the underhood fuse box.
• The ENG 1 fuse is blown in the underhood fuse box (not very common).

Your next step is to check the fuse and retest for the presence of 10 to 12 Volts in terminal A.