1978 GMC C Series TSBs

antilock brake, instrument panel, body control, power interface, etc.) reprogramming. Control module calibrations are regularly updated for many reasons. These reasons may include, but are not limited to: model year change, software corrections, certification compliance, product improvement and specific application requirements. However, the mere existence of a newer control module calibration does not necessarily mean that warranty coverage exists or that the calibration must be installed. It is not our policy to update control modules, under warranty or after warranty, based solely on the availability of a newer calibration file. Below are our guidelines for reprogramming control modules.