Wrangler 4WD L4-150 2.5L VIN P MFI (1998)
Powertrain Control Module: Description and Operation
(ASD) Relay Sense-PCM Input
AUTOMATIC SHUTDOWN (ASD) RELAY SENSE-PCM INPUT
Fig. 2 Power Distribution Center (PDC)
A 12 volt signal at this input indicates to the powertrain control module (PCM) that the Automatic Shutdown (ASD) has been activated. The ASD
relay is located in the Power Distribution Center (PDC). The PDC is located in the engine compartment (Fig. 2). Refer to label on PDC cover for
relay location. The ASD relay is used to connect the oxygen sensor heater elements, ignition coil, and fuel injectors to the 12 volt + power supply.
Jeep models of previous years had used the ASD relay to apply the 12 volt + power supply to the generator field source (+) circuit. This generator
circuit is now supplied 12 volts + directly from the PCM.
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).
