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P233A

Fuel Pressure Regulator C Control Circuit Open

The ECU detects an open circuit on the control line for the third (C) fuel pressure regulator. Either the regulator solenoid coil is internally open, the harness is broken, or the connector has lost contact - the ECU cannot drive the regulator and rail pressure cannot be controlled by this stage.

  • Check engine light: Yes
  • Emissions related: Yes
  • Repair difficulty: medium

Symptoms

  • Check engine light on
  • Hard start, no start, or stalling under load
  • Power loss especially at high load or rpm
  • Possible long cranking time

Common causes

Ordered by how often each turns out to be the cause.

  • Open circuit in harness or connectorCommon
  • Regulator solenoid winding openPossible
  • Pin pushed back out of connector bodyLess likely

Parts involved

  • Fuel Pressure Regulator C
  • Fuel Rail
  • Fuel Pump Supply

P233A is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.