[bfluker90]

i have a 2001 dodge diesel i just bought it the dealer was having a problem with it shutting down and come to find out it was a shut down relay they said the tuner caused it which i was told the tuners wont do that. and sense i bought it it seems to skip at a idle and when i coast to a stop sign or stop light. so im just wondering what is causing this to happen and also i put the tuner back on it today and it is telling me two codes one is p1693(fault in companion modual) and the other is p0645 control circuit/open. what does this mean???????????