97 Caravan Check Engine Light

Hi -
The Check Engine Soon light is on on my 1997 Grand Caravan (3.3l engine).
I checked the codes and got 12 - 31 - 55. According to AllPar.com, that
means the battery has been disconnected recently (it hasn't) and it has a
Bad Evaporator Purge Solenoid Circuit or Driver. The battery could be
because of some corrosion on the terminals? I have no idea what to do to
repair the other code. The gas cap was not loose. Any tips on how to check
this out?
Thanks -
Brian

 

Never mind code 12, that one always comes up when a fault code is set. Also
never mind 55, it is just indicating end of codes. Code 31 does deal with
the fuel evaporative system, but there are several items that can cause code
31. To get more details a proper DTC scanner test is requires. That will
break the code down further. Quick thing to check first though, code 31 can
be set by the system detecting a leak in the fuel evap vacuum system. That
is after all what it is there and is monitoring for. Check the hoses for
disconnects, cracks/leaks, pinches/kinks. 3 from the evap canister - one to
the tank rollover valve, one to the solenoid and onto the throttle body and
one to the canister vent valve and pump. check the connections to the
canister vent valve/pump and also to the solenoid. After that it could be
the pump, the solenoid, or the wiring to either. That is where a proper scan
comes in handy.