PO443 Code and Will Not Always Start.

by Ray
(Rochester, NY USA)

My 04 impala has had a starting problem for a couple of months now. I had a new Body Control Module installed last week as it would have several codes when trying to start. I had it towed to a dealer and installed. It still has a starting problem with po443 code and somtimes 2 times. If I leave it for a few hours it will generally start.
Do you know if this code would give this problem of hard to start? Sometimes the security light flashes and somtimes it may not when trying to start. EVAP purge valve C fault. Is C for closed?



Steve Says,


Hi, Ray. Thanks for using my website. Code p0443 is for Evaporative Emission Control System Purge Control Valve Circuit. There are several things to consider.


First of all, yes, it is possible that this has something to do with your starting problem. BUT the first thing that I would do is have the dealer check out the security system and find out why the light comes on. It is possible that this is the source of your starting problems. The security system can create a no-start condition.


That being said if this proves to not be the answer then the next thing I would check would be the Fuel Limiter Vent Valve (FLVV). It is a valve that is located in the fuel tank that will close off the charcoal canister vent port inside the fuel tank. It seals off the vent hose between the fuel tank and the charcoal canister when the tank is full. The fuel tank would have to be removed as well as the fuel pump assembly. After the tank is removed a good technician can tell if this valve is causing the problem or not. Most of the time you can just look inside the tank and see if it is broken and most of the time you can find the valve in the bottom of the tank. If the fuel tank does have to be removed you are looking at probably 4 hrs of labor or so.


It is also possible that you have some other problem with your evap system. You could have a wiring problem or a problem with another of the connectors in the system. You could also have a problem with your cars computer although this would not be likely.