Dakota R/T 2WD V8-5.9L VIN Z LDC (1999)
Automatic Shut Down (ASD) Relay: Description and Operation
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.
AUTOMATIC SHUTDOWN (ASD) RELAY SENSE-PCM INPUT
Power Distribution Center (PDC)
A 12 volt signal at this input indicates to the Powertrain Control Module (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. 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 only to sense that the ASD relay is energized. If the PCM does not see 12 volts at this input when the ASD should be activated,
it will set a Diagnostic Trouble Code (DTC).
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, ignition coil and oxygen (O2S) 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.
CCD BUS (+1-) CIRCUITS-PCM OUTPUTS
The Powertrain Control Module (PCM) sends certain output signals through the CCD bus circuits. These signals are used to control certain
instrument panel located items and to determine certain identification numbers.
