No Crank Loss Of Communication With High Speed GMLAN - keywords BCM data EBCM ECM no start TCM VCIM

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

A customer may comment of a no crank condition, may have multiple MILs illuminated or a dealer may experience loss of communication to all High Speed GMLAN modules with various communication DTCs stored. This may become an intermittent concern and be difficult for the technician to duplicate.

Have the dealer inspect for damaged wiring at the steering column. This condition can be very intermittent, depending on the position of the steering wheel and how often the Tilt/Telescopic position is adjusted. It will be necessary to remove the upper and lower column trim covers to inspect the harness for damage. There are two harnesses on the right hand side of the column that go up to the steering wheel area. One or both of these harnesses may be chaffing against the column's Tilt/Telescopic adjustment mechanism. The wire harness may have a rubber band on it that holds a loop in the harness, pushing it into this adjustment mechanism. Please remove this rubber band, repair damaged wiring following published wire repair procedures and re-position the harness away from the adjustment mechanism.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.