TEST 4: Testing The EGR Vacuum Regulator Solenoid (Part 1)

Testing The EGR Vacuum Regulator Solenoid (Part 1)

The first part of this test is to verify that the EGR Vacuum Regulator Solenoid is getting getting a good supply of engine vacuum from the intake manifold. Depending on the result of this test, the next test is to check to see if the EGR Vacuum Regulator Solenoid is getting power (12 Volts), in TEST 5.

You can use a vacuum gauge if you want, but it isn't necessary since all we need to ascertain is that engine vacuum is reaching the EGR Valve Vacuum Regulator Solenoid. OK, here's the test:

  1. With the engine off, disconnect the two vacuum hoses that connect to the EGR Valve Vacuum Regulator Solenoid.
    1. These two vacuum lines can be very hard to take off from the EGR Valve Vacuum Regulator Solenoid's nipples, if they have never been removed before.
    2. You have to be very careful as you pull on them since you could break the EGR Vacuum Regulator Solenoid in the process.
  2. Once the vacuum plastic vacuum lines are off, have your helper start the engine.
  3. One of the two vacuum lines/hoses will have engine vacuum.
    1. If the vacuum lines are color coded, the line that is green is the one that usually connects to the intake manifold and is the one that feeds vacuum to the EGR Valve Vacuum Regulator Solenoid.
    2. The other vacuum line is the one that feeds vacuum to the EGR valve once the PCM commands the EGR Valve Vacuum Regulator Solenoid to come on.
    3. If the vacuum lines are not color coded, no big deal... one of the two vacuum hoses/lines will have engine vacuum.

Let's find out what your test results mean:

CASE 1: If engine vacuum was present after the engine was started and was idling, This indicates that the vacuum line is good and delivering the goods to the EGR Vacuum Regulator Solenoid. The next step is now to test the Power Circuit (12 Volt) of the EGR Valve Vacuum Regulator Solenoid, go to: TEST 5: Testing The EGR Vacuum Regulator Solenoid (Part 2).

CASE 2: If engine vacuum WAS NOT present when the engine after the engine was started and was idling: This lack of vacuum will cause the EGR valve not to function and will light up your check engine light (CEL) with an EGR valve fault code. Repairing and/or replacing whatever is necessary to get vacuum to the EGR Vacuum Regulator Solenoid (when the engine is idling) should solve your EGR valve issue on your Ford (or Mercury, or Lincoln) car or truck.

TEST 5: Testing The EGR Vacuum Regulator Solenoid (Part 2)

Testing The EGR Vacuum Regulator Solenoid (Part 2)

The second part of this test is to verify that the EGR Vacuum Regulator Solenoid is getting power (12 Volts). The third part (TEST 6) is to test to see if it is allowing vacuum to pass thru' to the EGR valve while you're driving the vehicle. For now, let's make sure its getting juice.

OK, this test can be performed with the EGR Vacuum Regulator Solenoid connected or disconnected from its connector. The test steps assume that you're testing the circuit with the connector connected to the vacuum Solenoid:

  1. Set your multimeter to Volts DC mode.
  2. Connect the red multimeter test lead (with an appropriate tool) to the wire identified with a number 2 in the photos of the image viewer.
  3. Connect the black multimeter test lead to a good Ground point on the engine or to the battery negative terminal.
  4. Have an assistant turn the key on or start the vehicle and notice the voltage reading on the multimeter.

Let's find out what your test results mean:

CASE 1: If 12 Volts were present when the key was turned to On, This indicates that the power circuit is good and delivering the goods to the EGR Vacuum Regulator Solenoid. The next step is now to dynamically test the EGR Valve Vacuum Regulator Solenoid, go to: TEST 6: Testing The EGR Vacuum Regulator Solenoid (Part 3).

CASE 2: If 12 Volts were NOT present when the key was turned to On, re-check all of your connections and multimeter setup. If the multimeter still does not register this voltage, you must find out why these 12 Volts are missing. These missing 10 to 12 Volts will cause the check engine light (CEL) to illuminate on your instrument cluster. Repairing the cause should solve your EGR valve issue on your Ford car or truck.