1985 Mercedes Benz 190D AutomaticFACTORY OEM SERVICE PROCEDURE

Pressure Control Flap

A vacuum operated pressure control flap is located in the air guide housing and is used to increase vacuum in the intake manifold. When the engine is running in EGR mode, the pressure control flap closes the fresh air duct. In closed condition, a minimum opening remains between pressure control flap and air guide housing which increases vacuum.

NOTE: DO NOT manually operate the linkage on vacuum control unit for pressure control flap.
Factory Service Tools

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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.