Good Morning all

Happy Holidays. About a month I left a post asking about a battery light that would come on and go off even though I had a new alternator and batteries installed. Well yesterday I started the truck and noticed the needle on the battery dial was lower then normal. The truck started but did not seem right. Long story short, I took it back to the shop. I left it running while I was talking the mechanic. When he tested the batteries they were down to 6.45. He told me to shut it off and they put a battery charger on it and charged the batteries. And then replaced the alternator. All is well except for the odometer went to all 8's when they started the truck. The speedometer works, but I cannot get the odometer to show anything but 8's Any ideas what the heck is wrong? It worked fine until the batteries drained due to the bad alternator.

Thanks in advance for all of your help

 

I can honestly say I've never heard of this happening... just searching I see a couple other threads with no real answers on it, but the main suggestion is to check the plugs on the PCM, and ensure they're tight.