Dodge Repair Questions? Ask a Mechanic for Answers ASAP
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Code 42 tells us there is a problem with the ASD system but isn't specific whether it's a control or output situation.
Control for the ASD is a ground circuit provided by the PCM (your engine controller) through the magnetic windings of the relay. Power to the windings is supplied by fuse "D" of the power distribution center, the underhood fuse box. This fuse also supplies power to the PCM. My info is sketchy and doesn't detail much more than a location for the fuse. It's located in the outer row of LARGE fuses in the PDC, and if looked at with the outer rail upward... is the fourth fuse from the left. A 30-amp circuit.
It might be something as simple as just replacing (or substituting) the ASD relay. If the engine fires up if you use another relay like A/C compressor... you're done.
Being able to extract codes from your PCM means it's been awake most of the time and perhaps the whole time (a major determining factor). Sometimes the code 42 is a sideshow, something that distracts us from the real act.
Try swapping a relay from a non-critical circuit to the ASD location and see what happens. You could buy a fresh relay but I try to keep costs as low as possible in the early stages of diagnosis. If you know the borrowed relay to be good, go ahead and swap it out.
You can test for ASD power output at the coil (unhandy) or at the injectors (easier). The green/ orange wire at the injectors or coil will be ASD output circuit and should show system voltage when the engine is cranked or running. System voltage varies and compares to what you would see when testing voltage at the battery directly.
This is just the start. If you find the relay swap to be ineffective, let me know and I'll shoot you some more in-depth testing.