What P0233 means
The fuel pump circuit has two sides: the primary circuit is the engine module's output to the fuel pump relay coil (or to a pump control module), the secondary circuit is the power circuit from relay contact or module to the pump itself.
How the engine computer detects it
P0233 reports brief, recurring dropouts in the pump power circuit that count neither as steadily low nor high. The secondary circuit is the power side of the same pump, not a second pump. No manufacturer using this code was found – GM counts intermittent faults within P0231/P0232/P023F, Ford's relay systems only use P0230–P0232; the description follows CARB's output monitoring requirement and Ford's description of the power circuit. Symptoms are occasional stumbling, stalling or starting problems.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Occasional stumbling or jerking
- Engine stalls now and then
- Occasional starting problems
- Check engine light on
Common causes
- Loose contact at pump connector, tank flange or relay socket Most likely
- Relay contacts burnt (intermittently high resistance) Possible
- Harness chafing at underbody or tank with intermittent contact Possible
- Pump motor with commutator or brush dropouts Less likely
How to diagnose P0233
- Read every stored code with an OBD-II scanner. If misfire or fuel trim codes are there too, fix those first: they often cause this one.
- Inspect the parts involved: fuel pump, fuel pump relay, fuel pump wiring.
- Work through the causes above from most to least likely, cheapest checks first.
- Clear the code and drive a full drive cycle to confirm the repair held.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 2
- Fuel and air metering (injector circuit)
- 33
- Specific fault
Questions drivers ask
Can I drive with code P0233?
Usually yes for a short time, if the car drives normally, the temperature gauge reads normal and the check engine light is steady. If the light flashes, the engine loses power or overheats, or other warning lights come on, pull over and have it checked.
Will my car pass an emissions inspection with P0233?
Probably not in states that test vehicles with an OBD-II scan: an emissions-related code that keeps the check engine light on is usually an automatic fail. Rules differ by state and county, so check yours.
Will P0233 clear by itself?
The light can go off after several drive cycles without the fault, but the code returns if the cause is still there. After a repair, the readiness monitors need a full drive cycle before an inspection.
Can I fix P0233 myself?
Often yes, with an OBD-II scanner and basic tools. Difficulty: medium. Start with the cheapest checks before replacing expensive parts.
This page is general information, not a substitute for a professional diagnosis. Repair costs are rough estimates for parts and labor and vary by vehicle and region.