It shuts down the voltage to the primary coil on the distributor, power to fuel injectors, and fuel pump also.
http://www.thecarconnection.com/Enthusiasts/Ask_a_Mechanic/Ask_A_Mechanic_October_13_2006.S209.A10959.html
In PDC, two large relays on the B side, closest to the fender. One is the fan relay, one is the ASD relay. It may be labeled "engine relay"
It is abbreviated ASD
Chrysler doesn't use shut off switches. The fuel system is computer controlled with relays.
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