How to Test if an EGR Valve is Good or Bad?

[LaJessica]

Testing the EGR valve involves the following steps: 1. Unplug the EGR valve connector. First, locate the power and ground wires of the EGR valve. 2. Connect one end of a 5W test light to a ground point and insert the other end into pin 1 of the EGR connector. If the test light illuminates, it indicates the power wire of the EGR valve, and pin 2 is the negative terminal, which is also the duty cycle signal wire controlled by the engine computer. The remaining three wires are the potentiometer signal wires. 3. Set the multimeter to the 20V range and insert the two probes into the power and ground wires of the potentiometer signal wires. The normal voltage should be 5V. 4. Then, plug the connector back into the EGR valve and measure the signal voltage inside the EGR valve. The normal reading should be around 0.7V. If it exceeds the normal range, the EGR valve is likely damaged. 5. Over time, carbon deposits can form inside the cooler due to the cooling fluid or rapid carbon buildup caused by faults in other working cylinders. You can use a safe solvent or mineral oil to clean the inside of the cooler. Completely fill the EGR cooler module assembly, position the exposed module surface facing upward, and soak the EGR cooler for a period before draining the liquid from it. 6. Rinse with mineral oil or solvent, and use compressed air to dry the inside of the EGR cooler. Shake it intermittently to remove loose debris inside the EGR coolant. Rinse the coolant side of the cooler with water to minimize the chance of solvent or cleaner entering the coolant.