RAM 2500 Truck 2WD L6-359 5.9L DSL Turbo VIN D FI (1997)
Automatic Shut Down (ASD) Relay: Description and Operation
Power Distribution Center
DESCRIPTION
This circuit controls operation of the Automatic Shut Down (ASD) relay. It provides the necessary power to operate the generator field control for
charging system operation.
OPERATION
The ground circuit for the coil in the ASD relay is controlled by the Powertrain Control Module (PCM). The PCM operates the relay by switching
the ground circuit ON and OFF.
CIRCUIT OPERATION
Circuit A16 from fuse 4 in the Power Distribution Center (PDC) supplies battery voltage to the contact side of the Automatic Shut Down (ASD)
relay. Circuit A16 is HOT at all times.
When the ignition switch is in the START or RUN position, it connects circuit Al from fuse 3 in the PDC to circuit A21. Circuit A21 powers
circuit F18 through fuse 9 in the fuse block. Circuit F18 supplies battery voltage to the coil side of the ASD relay. The Powertrain Control Module
(PCM) provides the ground path for the coil side of the relay on circuit K51. Circuit K51 connects to cavity 51 of the PCM connector.
When the PCM provides grounds the ASD relay, the relay contacts close and connect circuit A16 to circuit A1 42. Circuit K125 splices to supply
voltage to the fuel injectors, ignition coil, and heated oxygen sensor. Circuit K125 also connects to cavity 57 of the PCM.
