2002 mercedes ml 500, 97000 miles error code P0446 INSTALL GAS CAP reset system code come on ever 1hr engine run ok ,it need new plugs, fuel miles in town 13 mpg
2002 Mercedes-Benz ml 500 v8
change gas cap check line to fuel tank
P0446 relates to a fuel tank shutoff valve not a purge system leak. Test for voltage at the valve. It is most likely time to replace the charcoal shut off valve.
4 years experience, Mercedes Benz Master Certified
is the charcoal shut off valve in the right hand side?
On that model I believe it is hidden by the frame above the spare tire. I will check when I arrive at work tomorrow and verifiy in the morning.
I was correct. The shut off valve is above the spare tire in the rear of the vehicle. Good Luck!Kevin