Quote Originally Posted by jonw View Post
Funny thing we had same problem last week. turned out to be separation arcing on transfer unit( broken housing the clip that holds it). don't know why it flagged up sc204 must be spiking something.. we insulated separation to test.
I know this is a 9 year old posting but thank you none the less. After 2 new BICU's and POlygon motors I found the grounding clip was likely not making contact with the rear bearing on the transfer roller. THis all started after I replaced the transfer case assy.