Dodge Durango

 Service Manual

Fuel System » Fuel injection system » Description and operation
Auto shutdown (asd) relay-pcm output

DESCRIPTION

The 5-pin, 12-volt, Automatic Shutdown (ASD) relay is located in the Power Distribution Center (PDC). Refer to label on PDC cover for relay location.

OPERATION

The ASD relay supplies battery voltage (12+ volts) to the fuel injectors and ignition coil(s). With certain emissions packages it also supplies 12-volts to the oxygen sensor heating elements.

The ground circuit for the coil within the ASD relay is controlled by the Powertrain Control Module (PCM). The PCM operates the ASD relay by switching its ground circuit on and off.

The ASD relay will be shut-down, meaning the 12-volt power supply to the ASD relay will be de-activated by the PCM if:

• the ignition key is left in the ON position. This is if the engine has not been running for approximately 1.8 seconds.
• there is a crankshaft position sensor signal to the PCM that is lower than pre-determined values

The PCM will sense if or when the ASD relay has been activated through a "sense circuit". Refer to Automatic Shut-Down (ASD) Relay Sense-PCM Input for additional information.

Powertrain control module (pcm)

Modes of operation

Automatic shutdown (asd) relay sense-pcm input

Battery voltage-pcm input

Brake switch-pcm input

Engine coolant temperature sensor-pcm input

Five volt sensor supplies-primary and secondary

Ignition circuit sense-pcm input

Intake manifold air temperature sensor-pcm input

Manifold absolute pressure (map) sensor-pcm input

Oil pressure sensor-pcm input

Oxygen sensor (o2s)-pcm input

Power grounds

Power steering pressure switch- pcm input

Sensor return-pcm input

Throttle position sensor (tps)-pcm input

Vehicle speed and distance-pcm input

Auto shutdown (asd) relay-pcm output

Ccd bus (+/-) circuits-pcm outputs

Data link connector-pcm input and output

Fuel injectors-pcm output

Fuel pump relay-pcm output

Idle air control (iac) motor-pcm output

Oxygen sensor heater relays-pcm output

Radiator cooling fan relay-pcm output

Throttle body