How To Test The EVAP Vent Solenoid (1999-2002 V8 Chevrolet Silverado, GMC Sierra)

Cleaning The EVAP Vent Solenoid

Because of where it's located, the EVAP vent solenoid's air filter can become clogged with dust/dirt.

Once the vent solenoid's air filter becomes clogged with dust, fresh air intake will be blocked to the EVAP carbon canister. This in turn will cause the fuel injection computer to set an EVAP system trouble code.

Thankfully cleaning the EVAP vent solenoid isn't hard, since it can be done with compressed air.

OK, these are the cleaning steps:

1. 1

   Blow compressed air into the fresh air outlet port.

2. 2

   Dust should blow out the end labeled fresh air intake in the photo above.

3. 3

   Continue blowing compressed air into the fresh air outlet port until dust no longer comes out the fresh air intake side of the air filter canister.

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

CASE 1: The compressed air blew out all of the dust clogging the EVAP vent solenoid's air filter. The EVAP vent solenoid is ready to be bench-tested. Go to TEST 3: Bench Testing The EVAP Vent Solenoid.

CASE 2: The compressed air DID NOT pass thru' the EVAP vent solenoid. This usually happens when the EVAP vent solenoid has failed internally and is stuck in its ON state. Replace the EVAP vent solenoid.

More Chevrolet Silverado (GMC Sierra) Tutorials

You can find a complete list of V8 Chevrolet Silverado (GMC Sierra) tutorials in this index:

• GM 4.8L, 5.3L, 6.0L Index Of Articles.

Here's a small sample of the tutorials you'll find in the index:

• Resistance Specifications Of The TAC Electronic Throttle Body.
• How To Test The GM Accelerator Pedal Position (APP) Sensor 2.
• How To Test The MAF Sensor (GM 4.8L, 5.3L, 6.0L, 8.1L).
• Blown Head Gasket Test (GM 4.8L, 5.3L, 6.0L).