Powertrain, generic (extended)

P233D Fuel Pressure Regulator B Solenoid Supply Voltage Control Circuit/Open

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Where the ECM switches the solenoid of fuel pressure regulator B on both sides, the ground-side line is checked under P2294 to P2296 and the feed from the high-side driver under P233D to P233F. P233D is the open-circuit code for that feed. No manufacturer documents it publicly: GM's 2025 diesel table 25OBDG04A, where regulator B is the rail pressure regulator valve, contains only the low and high codes of this circuit and folds a broken feed into its regulator tests. The basis is therefore CARB's rule that output components be checked for circuit continuity. An open feed leaves the valve without current regardless of command, so the ECM loses its means of setting rail pressure; depending on the system the pressure rises or collapses, typically with reduced power.

Likely causes

Supply wire to the regulator solenoid broken or terminal loose
Corrosion at the regulator connector
Regulator solenoid winding open
High-side driver in the engine control module faulty

Symptoms

  • Check engine light on
  • Rail pressure not controllable, reduced power
  • Possibly hard starting or stalling

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–700
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

fuel pressure regulator bengine control modulewiring harness

Related codes

P233EP233FP2294P2293P00C8

References: law.cornell.edu, gsi.ext.gm.com.