Oh, I hate my EGR valve!!! I'm on my third EGR and my code P0405 has just started popping up again!
Here is a
nice video explaining your P1405 error code.
In my case, I had a couple codes originally, but after cleaning the OEM EGR valve pintle, I was able to eliminate one code, leaving just the P0405. My OEM and 3-month old NAPA EGR valve were returning the same error, which led me to believe it was something else. After months of troubleshooting, I took the VX to a local shop, who compared my EGR valves to a shelf unit, determining both of my units to be faulty. The NAPA was still under warranty, and they replaced it for free.
But, now the same code has returned (after driving in the rain) which makes me suspect that something is causing my VX to burn up EGR valve electronics. Interestingly, the code has only popped up when I moved the VX from one location to another when cold, maybe running for one minute. The code then popped up on the next restart. I've been able to clear the code each time. Today I have to do the same thing - move my car out of the garage into the driveway for garage maintenance, so I will be able to verify if the code is repeatable. If the code returns today, I will be calling the local shop for their opinion. I'm hoping they will bench test my EGR valve for free, and if it reports faulty I will have to either buy a case of eBay valves, or have them chase down an electrical problem in my VX.
Did I mention - I hate my EGR valve!!