QuestionMy van popped the Check Engine Light last week. I found out how to check the codes online and got a code reading of P0406 . I found the meaning of this code to be: "Exhaust Gas Recirculation Sensor A Circuit High."
What does this mean, and why can none of my local parts stores seem to find the EGR sensor if this is indeed the part that needs to be replaced?
AnswerHi Eric,
This system is a little bit beyond the year limits of my claim of "expertise". I suspect the sensor is built-in to the egr valve's solenoid itself, thus no part would be available. I have a 2001 manual that lists the menaing as the voltage on the sensor cicuit exceeds 5V, as the basis for setting the code. That could be due to the following:
egr position sensor sweep (that must mean something related to the solenoid motion being out of range)
the signal sensor circuit could be shorted to the 5 volt supply system
the signal sensor circuit could be shorted to the battery
the solenoid assembly could have an internal failure
the egr position sensor signal circuit open
sensor ground circuits open
a faulty powertrain controller
Without a circuit diagram I think the best bet if the part is not too expensive would be to replace the egr solenoid, and also check the electrical wires supplying it for burnthrough of the insulation, etc.
Roland
