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


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.


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.
    More about «Description and operation»:

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    Automatic shutdown (asd) relay sense-pcm input

    Battery voltage-pcm input

    Brake switch-pcm input

    Five volt sensor supplies-primary and secondary

    Fuel level sensor-pcm input

    Engine coolant temperature sensor-pcm input

    Extended idle switch-pcm input

    Oxygen sensor-pcm input

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    Intake manifold air temperature sensor-pcm input

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    Oil pressure sensor-pcm input

    Power grounds

    Power steering pressure switch- pcm input

    Sensor return-pcm input

    Throttle position sensor (tps)-pcm input

    Vehicle speed and distance sensor- 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

    Radiator fan relay-pcm output

    Throttle body

    Jeep Cherokee Service Manual / Fuel system / Fuel injection system / Description and operation / Auto shutdown (asd) relay-pcm output

    Jeep Cherokee Service Manual


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