I have a 2008 Express 2500 with an intermittent loss of communication to ABS module when vehicle is first started up and idle. When driving, light goes out and does not come back on until engine is switched off and started again. I did the full truck ground wire re-seating to bare metal connections and dielectric grease. I noticed a pink wire that runs from drivers seat fuse panel, through floor board and goes into harness but it looks like it was not done by factory. I don't have a schematic on the harness and GM's fix is to replace ABS module and wire harness, $1400.00. Any help would be appreciated