2003 chevy 1500 4.8 4x4 no comunication from bcm , theft light on flashes, abs/parking light on , puts truck in limp whith lean fuel out... replaced key lock cyl/ and switch also bcm still same thing cked grounds under dr door ok????? dont know what to do amp gage speraticly drops down to 9 amps then will go back up just sitting there with not doing nothing????