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Pinpoint Test Av : A Loud Popping Sound Is Heard From The Speakers When Cycling The Ignition

WARNING: This page is about a different car, the 2016 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

  1. AV1 CHECK THE START SENSE CIRCUIT FOR A SHORT TO GROUND

    • Ignition OFF.
    • Disconnect: ACM C240A .
    • Disconnect: PCM C175B .
    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C240A-3
      GFD134423Courtesy of FORD MOTOR COMPANY
      Ground

    Is the resistance greater than 10, 000 ohms? 

    Yes  GO to  AV2.
    No  REPAIR the circuit.
  2. AV2 CHECK THE START SENSE CIRCUIT FOR AN OPEN

    • Measure:
      Positive Lead Measurement / Action Negative Lead
      C240A-3
      GFD134423Courtesy of FORD MOTOR COMPANY
      C175B-62

    Is the resistance less than 3 ohms? 

    Yes  GO to  AV3.
    No  REPAIR the circuit.
  3. AV3 CHECK FOR CORRECT ACM OPERATION

    • Ignition OFF.
    • Disconnect and inspect all the ACM connectors and related in-line connectors.
    • Repair:
      • Corrosion (clean module pins or install new connectors or terminals)
      • Damaged or bent pins (install new terminals or pins)
      • Pushed-out pins (install new pins as necessary)
    • Reconnect the ACM connectors and related in-line connectors. Make sure they seat and latch correctly.
    • Operate the system and determine if the concern is still present.

    Is the concern still present? 

    Yes  CHECK OASIS for any applicable TSBs. If a TSB exists for this concern, DISCONTINUE this test and FOLLOW TSB instructions. If no TSBs address this concern, INSTALL a new ACM. REFER to Audio Control Module (ACM) .
    No  The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.