Hey I have a 2006 ford five hundred and one day the engine started shaking and the check engine light came on and the air conditioner stopped working. The fan works but the air conditioner wont blow out real cold air. So i took it to a place that will check it for u for free. its a transmission place so they didnt know that much for sure but they pulled this code up. it was p0351 and they wrote beside that ignition coil and below that they wrote (A) pri/sec circuit fault. They said they think that it needs an ignition coil replaced but theyre not for sure cause they only deal with transmissions and there wasn't anything wrong with my transmission. Can anyone help?