Rick's Free Auto Repair Advice


P0406 Exhaust Gas Recirculation (EGR) A Circuit High

If you have a P0406 Exhaust Gas Recirculation (EGR) A Circuit High trouble code, read this to understand what it means.

Engines recirculate a small amount of exhaust back into the intake manifold to reduce combustion temperatures and lower smog causing oxides of nitrogen emissions. The computer commands the EGR valve to open a certain amount and then checks to make sure it’s operating properly. One way to check is to mount a position sensor on the shaft of the EGR valve and generate a voltage value depending on how far the shaft moves. If the computer senses too high of a reading from the position sensor, it will set a P0406 code. That can either mean a bad position sensor, a bad EGR valve, or a wiring problem in the circuit. Don’t automatically assume it’s a bad EGR valve.

© 2012 Rick Muscoplat

Posted on by Rick Muscoplat

Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN