Self-Diagnostic Mode

1984 Plymouth Horizon Base, 1.6 ASECTION Self-Diagnostic Mode
WARNING: This page is about a different car, the 1994 Chrysler LeBaron. However, it is still accessible from the selected car via links, so may be relevant.

VTSS self-diagnostic mode verifies operation of all monitored switches/circuits. There are NO codes for the VTSS, only symptoms. To enter self-diagnostic mode without DRB, turn ignition switch to ACC (accessory) position 3 times, leaving switch in this position.

Upon entering self-diagnostic mode, horn should sound at each of the following events, to indicate proper operation.

  • Beginning with doors closed, open then close each door. The horn should sound when door ajar switch closes and then again when switch opens. Wait one second when opening/closing door ajar switch (door).
  • Open and close hood. The horn should sound when hood is opened then closed. Actuate power door locks in both the lock and unlock direction. The horn should sound after each actuation.
  • Using key, rotate each door lock cylinder to unlock position. The horn should sound when switch closes and then again when switch opens. Wait one second when opening/closing switch, or the horn will not sound.
  • Turn ignition switch to RUN position. Horn should sound once to indicate proper operation of ignition (switch) input. This step will also take VTSS module out of self-diagnostic mode.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.