My 2004 Dodge Intrepid is coming up with the codes P1687 and p1681, what does this mean?

Question

I just had the check engine light fixed and it was an oxygen sensor. 2 weeks later these codes are coming up.

Answer 1

P1681 1T PCM 2003 300M, Concorde, Intrepid No Fuel Level Bus Messages Conditions: Key on, and the PCM determined that it did not receive any Fuel Level messages over the Data Bus line for 20 seconds. Possible Causes: Data Bus circuit from BCM to PCM is damaged or it has failed Fuel level Bus message to the PCM is invalid BCM is damaged or has failed PCM unable to communicate with the Body Control Module

P1687 1T PCM 2000-04 300M, Concorde, Intrepid, LHS No Cluster Bus Messages Conditions: Key on or engine running; and the PCM determined that it did not receive any Security Key Bus Messages over the Data Bus line for 20 seconds. This malfunction may be an intermittent problem. Possible Causes: Data Bus circuit from SKIM to PCM is damaged or it is open PCM unable to communicate with the Body Control Module PCM has failed, or the SKIM is damaged or has failed

I got these from the auto repair section of autozone.com as to what they mean, I don't know.  Hope this is a start.  Good Luck.