Powertrain Control Module Controlled Air Conditioning (A/C) Circuit Diagnosis

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    Circuit Description

    When an A/C mode is selected, the A/C control head or the A/C programmer supplies a 12 volt signal to the PCM A/C request input. The A/C compressor clutch relay is controlled by the PCM. The PCM provides a ground path for the A/C relay c...

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    Service Manual Table of Contents

    Document Tags

    Document Title: Powertrain Control Module Controlled Air Conditioning (A/C) Circuit Diagnosis

    circuit

    when

    mode

    selected

    control

    head

    programmer

    volt

    signal

    request

    compressor

    clutch

    relay

    ground

    engaged

    battery

    voltage

    engine

    following

    conditions

    greater

    pressure

    psi

    refrigerant

    sensor

    speed

    time

    diagnostic

    check

    poor

    connection

    harness

    terminals

    disconnect

    ignition

    observe

    connector

    test

    diagnosis

    replacement

    feed

    determines

    problem

    vehicle

    powertrain

    module

    action

    value

    system

    important

    temperature

    start

    hvac

    scan

    tool

    switch

    turn

    measure

    specified

    open

    found

    repair

    procedures

    electrical

    heater

    ventilation

    conditioning

    connect

    resistance

    reference

    locate

    refer

    probe

    light

    replace

    short

    complete

    compressor relay

    pressure sensor

    engine speed

    speed greater

    relay control

    control circuit

    harness connector

    clutch engaged

    ignition feed

    feed circuit

    powertrain control

    control module

    clutch control

    ignition switch

    turn ignition

    measure voltage

    request circuit

    voltage measure

    specified value

    problem found

    repair repair

    diagnosis problem

    conditioning hvac

    circuit poor

    refrigerant pressure

    signal circuit

    volt reference

    reference circuit

    ground circuit

    test light

    short ground

    pressure signal

    locate repair

    repair short

    action complete

    diagnosis action

    throttle angle greater

    head pressure greater

    pressure greater psi

    engine speed greater

    speed greater rpm

    check following conditions

    relay control circuit

    diagnostic trouble codes

    compressor clutch engaged

    compressor clutch engage

    ignition feed circuit

    powertrain control module

    control module replacement

    module replacement programming

    compressor clutch control

    clutch control circuit

    powertrain board diagnostic

    important continuing diagnosis

    continuing diagnosis following

    diagnosis following conditions

    must ambient temperature

    ambient temperature greater

    engine coolant temperature

    start idle engine

    mode hvac control

    hvac control head

    turn ignition switch

    voltage measure specified

    measure specified value

    problem found repair

    found repair repair

    repair repair procedures

    diagnosis problem found

    circuit poor connection

    refrigerant pressure sensor

    volt reference circuit

    sensor ground circuit

    resistance higher specified

    higher specified value

    connector test light

    test light ground

    check poor connections

    problem found replace

    found replace loose

    replace loose terminals

    loose terminals necessary

    refer repair procedures

    compressor clutch electrical

    open short ground

    refrigerant pressure signal

    pressure signal circuit

    ground voltage measure

    reference circuit poor

    signal circuit poor

    locate repair short

    repair short voltage

    control circuit repair

    circuit repair procedures

    diagnosis action complete