P233F code meaning
Fuel Pressure Regulator B Solenoid Supply Voltage Control Circuit High
Powertrain system Generic code P23xx codes Check engine light
What P233F means
P233F is set when the feed line of the fuel pressure regulator B solenoid carries voltage even though the ECM has its high-side driver switched off. GM's 2025 diesel table 25OBDG04A describes this test for the rail pressure regulator valve: in the off state the voltage across the driver should be large; if it is low, the line is fed from elsewhere, as if tied to power through less than half an ohm. As with the ground short, 61 failures in 122 samples of 6.25 ms decide, and the code is Type A. A permanently powered feed means the valve can only be controlled via the low side, or is energised continuously if that side is also faulty, so rail pressure may drift from target. Typical findings are a harness touching a battery feed or a damaged connector. P233E is the low counterpart.
P233F at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P233F
- Check engine light on in the first trip
- Rail pressure too high or unstable
- Reduced engine power possible
Common causes of P233F
- Most likelyRegulator supply wire touching a battery or ignition feed
- PossibleBent or bridged pins in the regulator connector
- Less likelyHigh-side driver in the engine control module stuck on
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Fuel pressure regulator bEngine control moduleWiring harness
What each part of P233F means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 3 | Area: ignition system or misfire. |
| 3F | The exact fault in that area. |
What to do next
- Note P233F and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P233F
What does P233F mean?
P233F means "Fuel Pressure Regulator B Solenoid Supply Voltage Control Circuit High". P233F is set when the feed line of the fuel pressure regulator B solenoid carries voltage even though the ECM has its high-side driver switched off. It is a generic code, so it means the same on every make.
Is it safe to drive with P233F?
Drive gently and only to a workshop. With P233F the car can go into limp mode (reduced power) to protect itself.
Will P233F fail an emissions test?
Yes, it can. P233F is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P233F to fix?
Difficulty: medium. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will P233F clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.