Test Ab: Left Seat Belt PRETENSIONER Circuit Short To Battery Or Ignition (DTC B1878): Description
WARNING: This page is about a different car, the 2002 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.
Restraints Control Module (RCM) monitors resistance on left seat belt pretensioner circuits. If RCM detects a short to battery or ignition, it will store Diagnostic Trouble Code (DTC) B1878 in memory and flash Code 17 on AIR BAG warning light.