RAM 1500 Van V8-5.2L CNG VIN T (1999)
Automatic Shut Down (ASD) Relay: Description and Operation
AUTOMATIC SHUTDOWN (ASD) RELAY - PCM INPUT
Power Distribution Center (PDC) Location
A 12 volt signal at this input indicates to the PCM that the ASD has been activated. The ASD relay is located in the Power Distribution Center
(PDC). The PDC is located in the engine compartment next to the battery. Refer to label on PDC cover for relay location. The relay is used to
connect the oxygen sensor heater element, ignition coil and fuel injectors to 12 volt + power supply.
This input is used to sense that the ASD relay is energized. If the powertrain control module (PCM) does not see 12 volts at this input when the
ASD should be activated, it will set a diagnostic trouble code (DTC).
The ASD relay is located in the Power Distribution Center (PDC).
The ASD supplies battery voltage to the fuel injectors and ignition coil(s). With certain emissions packages it also supplies voltage to the oxygen
sensor heating elements. 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.
AUTO SHUTDOWN (ASD) RELAY - PCM OUTPUT
The ASD relay is located in the Power Distribution Center (PDC).
The ASD supplies battery voltage to the fuel injectors and ignition coil(s). With certain emissions packages it also supplies voltage to the oxygen
sensor heating elements. 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.
Refer to Instrument Panel and Gauges for additional information.
AUTOMATIC SHUTDOWN (ASD) RELAY
As one of its functions, the ASD relay will supply battery voltage to the ignition coil. The ground circuit for the ASD relay is controlled by the
Powertrain Control Module (PCM). The PCM regulates ASD relay operation by switching the ground circuit on-and-off.
