The EGR vacuum solenoid is a simple ON/OFF solenoid that can easily be tested to determine whether it's good or bad.
In this tutorial, I'll explain how step by step. Then, with your test results, you'll easily and quickly troubleshoot the EGR vacuum solenoid as good or bad.
Contents of this tutorial:
- Symptoms Of A Bad EGR Vacuum Solenoid.
- How The EGR Vacuum Solenoid Works.
- Where To Buy The EGR Vacuum Solenoid And Save.
- TEST 1: Is The EGR Vacuum Solenoid Stuck Open?.
- TEST 2: Applying 12 Volts And Ground To The EGR Vacuum Solenoid.
- TEST 3: EGR Vacuum Solenoid Resistance Test.
- More 2.2L Beretta, Cavalier, Corsica, And Sunfire Diagnostic Tutorials.
You can find this tutorial in Spanish here: Cómo Probar El Solenoide De La Válvula EGR (1992-1995 2.2L Beretta, Cavalier, Corsica, Sunfire) (at: autotecnico-online.com).
APPLIES TO: This tutorial applies to the following vehicles:
- 2.2L Chevrolet Beretta: 1992, 1993, 1994, 1995.
- 2.2L Chevrolet Cavalier: 1992, 1993, 1994, 1995.
- 2.2L Chevrolet Corsica: 1992, 1993, 1994, 1995.
- 2.2L Pontiac Sunfire: 1995.
EGR VALVE TEST: You can find the EGR valve test here:
Symptoms Of A Bad EGR Vacuum Solenoid
The EGR system, which includes the EGR valve and the EGR vacuum solenoid, is monitored by the fuel injection computer as the engine runs.
So when an EGR system malfunction occurs, the fuel injection computer will set an EGR system diagnostic trouble code and illuminate the check engine light.
You'll see the following OBD I EGR system diagnostic trouble code:
- Code 32: EGR system problem.
How The EGR Vacuum Solenoid Works
The EGR vacuum solenoid is the fuel injection computer's component to regulate the vacuum supply to the EGR valve.
As you're probably already aware, when the EGR valve receives vacuum, it opens and allows exhaust gas into the intake manifold.
In a nutshell, this is how the EGR vacuum solenoid works:
- The EGR vacuum solenoid receives 12 Volts DC as soon as the engine is started but remains OFF (does not allow vacuum to pass thru it).
- Once the engine has reached its normal operating temperature and it's under load, the fuel injection computer commands the EGR vacuum solenoid ON.
- The fuel injection computer commands the EGR vacuum solenoid ON by internally grounding it.
- In its ON state, the vacuum solenoid will allow vacuum entering its inlet port to pass to its outlet port. Since the outlet port is connected to the EGR valve, vacuum now reaches the EGR valve.
It's important to note that the EGR vacuum solenoid is normally closed. In other words, it does not allow vacuum to pass from its inlet port to its outlet port (until commanded ON).
Where To Buy The EGR Vacuum Solenoid And Save
The following links will help you comparison shop for the EGR vacuum solenoid of known automotive brands (no knock-off parts).
TEST 1: Is The EGR Vacuum Solenoid Stuck Open?
The EGR vacuum solenoid is normally 'closed' until the fuel injection computer commands it ON.
In this closed state, the EGR vacuum solenoid does not allow vacuum to pass from its inlet port to its outlet port.
To get our EGR vacuum solenoid diagnostic underway, we'll check to see if the solenoid is stuck open, allowing air to pass from one port to the other.
NOTE: You'll need a vacuum hose to attach to the EGR vacuum solenoid's inlet port.
These are the test steps:
Disconnect the EGR vacuum solenoid from its electrical connector .
Remove the EGR vacuum solenoid from its place on the intake manifold.
Connect a vacuum hose to its inlet port .
Blow air through the vacuum hose. You can use your mouth to blow air into the vacuum hose.
Air should not pass to the outlet port .
NOTE: Air may pass thru the solenoid (its vented to atmosphere), but it should NOT come out of its outlet port.
Let's take a look at what your test results mean:
CASE 1: Air DID NOT pass through to the outlet port. This is the correct and expected test result.
The next test is to apply power and Ground directly to the EGR vacuum solenoid. For this test go to: TEST 2: Applying 12 Volts And Ground To The EGR Vacuum Solenoid.
CASE 2: Air passed through to the outlet port. This test result confirms that the EGR vacuum solenoid is bad.
Replace the EGR vacuum solenoid.