P0234 OBD II Trouble Code Turbocharger/Supercharger Overboost Condition DTC

Symptoms of P0234 OBD II Trouble Code

  • The service engine soon or check engine light will illuminate.
  • You will experience a loss of power.
  • The engine may show signs of overheating.
  • The transmission may show signs of overheating and harsh shifting.
  • Additional codes associated with the condition set by P0234 may be present to help identify the cause. Codes are available for all electrical components utilized by the engine management computer for the control of boost levels.
  • The engine may display signs of pre-ignition in the form of knocking.
  • The engine may display ignition misfiring.

Common Causes of P0234 OBD II Trouble Code

  • In lieu of further trouble codes associated with the overboost condition it would be safe to say the problem is mechanical. The operation of the wastegate is the most probable.
  • The wastegate is either stuck closed causing the turbo to spin higher than normal, thus causing the overboost.
  • The rod from the wastegate actuator to the wastegate on the turbo is bent.
  • A hose came off the wastegate or boost controller.
  • A supply house to the boost controller or from the controller to the wastegate is clogged.
  • Dodge trucks with a Cummins diesel have a peculiar problem. They run fine but the check engine light comes on and sets code P0234 at an idle, yet the light goes out several minutes later at cruise speeds. The digital boost control gauge is connected into the MAP sensor which has an intermittent fault at idle yet does not set a code. Replacement of the MAP sensor corrects this.