BCM Code B336: Loss Of IPC Data: Notes
WARNING: This page is about a different car, the 1990 Cadillac Seville and 1990 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
If BCM loses data communication with IPC and ignition is on, Code B336 will be set. The problem is a result of 7-volt or ground fault to IPC or double open circuit in data communication line between IPC and BCM. If this failure occurs, cruise control will disengage (if engaged) and headlights (if on) will function on low beam.