Getting ready for another emissions test? Make sure your vehicle will pass even the most stringent of smog tests by keeping your EGR (exhaust gas recirculation) system in prime shape. Conduct thorough testing of the EGR parts to ensure that the system is working properly. To test the EGR position sensor, follow the steps listed below.
Difficulty level: Moderate
- Vacuum pump
- Ohm or digital volt meter
Step 1: Locate the EGR valve position sensor. In most vehicles, this sensor can be found on the EGR valve.
Step 2: Once you've found the EGR valve position sensor, look for its middle wire. That's the "Signal Return" wire. It's where you'll attach the red positive meter lead. Just push the meter lead into the sensor's wiring connector.
Step 3: Take your black negative meter lead and connect it to your engine block. Make sure both connections are secure.
Step 4: Start your engine and look at the digital volt or ohm meter. While the engine is idling, the meter should read anywhere between 0.24 and 0.67 volts. Now, turn the ignition key to the "Run" position.
Step 5: Find the EGR valve and locate its vacuum port side. There should be a vacuum line connected to it. Simply unplug this line.
Step 6: Using your handheld vacuum pump, bring in four inches of vacuum to the valve's vacuum port.
Step 7: Check your meter. At this point, the voltage shown should be anywhere from 2.15 to 2.65 volts.
Step 8: Now, try applying eight inches of vacuum to the vacuum port. The meter should display a number that ranges from 3.9 to 4.4 volts.
Step 9: If your meter's readings are off, or if the voltage keeps dropping to zero, replace your current EGR valve position sensor.
When conducting this test , don't use an analog meter. The analog meter will be using high current flow that may damage your engine computer. Use a digital ohm or volt meter instead.