P0406 code on a 2008 Dodge Ram 1500 5.7 Hemi?

Question

In February 2014, the engine lite would come on and would remain on. In an effort to troubleshoot the problem (as I am a do-it-yourself kinda guy) I bought an Actron CP9575 AutoScanner OBDII Scan Tool. Using this tool, I would reset the code P0405 code (Exhaust Gas Recirculation Position Sensor Circuit High), clearing the engine light. Within a few driven miles the engine light would re-illuminate. I would reset the code and this process would repeat. I replaced the EGR valve 2/27/14. After clearing the code, the engine line remained off.

Now, 3 months later, I am getting the P0406 code again. However, when I reset the code this go-around the engine light would stay off for a few days, then re-illuminate. I checked the installation done back in February - all bolts and the electrical connection are tight. Could it be the new EGR valve is failing just outside of the 90 day warranty? Just my luck.

Is there anything else that could be causing the P0405 code?

Carl

Answer 1

P0405 EGR position sensor circuit low.

This is circuit low. the EGR sensor circuit is low . One of the jobs for the ECM is to look for open, short and ground ,and rationality. With the EGR plugged in if the sensor circuit goes low then this becomes a EGR problem , With the EGR disconnected the EGR should go high. See if the Actron has a EGR datastream for the EGR and make a comparision of the EGR voltage connected and disconnected with the engine at idle.What usually causes a P0405 is a failed EGR valve shorting internally.