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OBD II Fault Code

  • OBD II P257A

OBD-II Code Climate control systems will not work is defined as a Vacuum Reservoir Control Circuit/Open

Diesel vehicles have a separate vacuum pump an reservoir because they cannot utilize vacuum from the engine the way a gasoline vehicles can. The engine control module (PCM) tells the vacuum pump when to turn on an off. If the PCM cannot control the pump, it will set code P257A.

Climate control systems will not work Symptoms

  • Climate control systems will not work

Common Problems That Trigger the P257A Code

  • Damaged vacuum reservoir
  • Powertrain Control Module (PCM) failure
  • Wiring issue
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