The increasing complexity of car electronics requires an ever advancing portfolio of diagnostic methods to pinpoint the root cause of the problem at hand. "The Good Stuff" is a collection of those methods, which we consider critical to our success.!...
Tracking down the offending circuit, whether a fuse blows on a constant or intermittent basis, is never easy. With the proliferation of low current automotive electronic devises today, fuses typically feed multiple circuits. Manually separating harness connection points or cutting into harness splice packs one by one in order to install your Ammeter and find the offending leg of a circuit can turn into a game of blind ditch digging in a hurry.
What is needed is a better way to “see” the offending circuit while using a map to enable us to dig a minimum of holes. A low current...
Airbag Testing
Airbag and seat belt detonator assemblies don’t use a separate removable resistance sensors, however they do have an intrinsic resistance value that the airbag ECU uses to “sense” a defective airbag circuit. With that in mind we can substitute a potentiometer (pot’) in place of the actual airbag assembly in order to determine if the airbag resistance itself is out of specification or if there is a defect within the harness going to the suspect airbag circuit or the module itself.I typically use 0 - 25 Ohm range pot to test airbag systems. You only need two of three...