Just found your site and first post so here goes.I have a 2002 Grand Caravan and driving to work this morning the check engine light came on. I did the key on - off and and the engine light did not blink but I got 5 chimes, a pause and then a single chime so I am assuming this is an error 51. The van itself is driving fine. The only problem we have at the moment is the passenger window motor needs to be replaced. Any help on what this code is would be greatly appreciated. Thank you in advance for your help!!

 

I have a 97 Caravan, and the code P0051 means the O2 sensor on 'bank 2', 'sensor 1' heater has a low or faulty circuit. This was pretty common in the 1st couple years of ownership. Pick up a scan tool and check it. If it is the O2 sensor you can replace it yourself and reset the MIL.