P0233

Universal

Fuel Pump Secondary Circuit Intermittent

Definition source: General OBD-II reference catalog
Definition verification: Not independently verified for display.
Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium
Medium Severity

The engine computer has detected an intermittent electrical condition in the fuel pump’s secondary circuit. This circuit helps operate or control the pump, which supplies fuel to the engine. A fault that comes and goes may cause poor running, stalling, or difficulty starting, but the code does not by itself prove that the pump needs replacement.

Report an error with this code

⚠️ Before You Begin (Safety First)

If the engine stalls, will not start reliably, or loses power in traffic, stop driving when it is safe and arrange diagnosis or towing. If you smell fuel or see a fuel leak, switch off the engine, keep away from ignition sources, and get professional help. Avoid working on fuel-system wiring near spilled fuel.

Common Symptoms

  • The engine may crank without starting if an intermittent circuit fault prevents the fuel pump from operating when needed.
  • The engine may hesitate, run poorly, or lose power if fuel delivery is interrupted intermittently.
  • The engine may stall if the circuit fault occurs while driving.
  • The warning light may be on even when no noticeable symptoms are present, especially if the fault is intermittent.

Common Causes

  • Loose, damaged, corroded, or intermittently connected wiring or connectors in the fuel pump secondary circuit.
  • An intermittent fault in a relay, fuse connection, or other circuit connection, depending on the vehicle design.
  • A fuel pump with an intermittent electrical fault; the code alone does not confirm that the pump is faulty.
  • An intermittent ground or control-side problem in the circuit.
  • A fault in a related control component, which should be considered only after the circuit and connections are tested.

Diagnostic Steps

  1. Note whether the vehicle has trouble starting, stalls, or loses power, and avoid driving it if those symptoms make it unsafe.
  2. Use a compatible scan tool to record the code and any related codes before clearing anything; related information can help guide diagnosis.
  3. With the vehicle safely parked and the ignition off, visually inspect accessible fuel-pump circuit wiring and connectors for looseness, damage, corrosion, or signs of overheating. Do not disconnect components unless the vehicle-specific procedure permits it.
  4. Check the owner’s manual for the correct fuse identification and inspect the relevant fuse only if it is safely accessible. A fuse that is blown may indicate another fault, so do not install a higher-rated fuse or repeatedly replace it.
  5. If the fault persists or requires electrical measurements, have a qualified technician test the circuit using vehicle-specific service information rather than replacing the pump based on the code alone.

When to Call a Professional

A technician can check stored and pending codes, review available fuel-pump control data, and test the circuit for intermittent power, ground, connection, or control problems. Diagnosis may require reproducing the fault while monitoring the circuit. Exact test points and procedures depend on the vehicle.

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Commonly Asked Questions

Does P0233 mean the fuel pump must be replaced?

No. It indicates an intermittent condition in the fuel pump secondary circuit. Wiring, connections, a relay or another circuit component may be involved, so testing is needed before replacing parts.

Can I keep driving with P0233?

That depends on the symptoms. If the engine stalls, loses power, or is unreliable to start, stop driving when safe and arrange diagnosis. A vehicle with no noticeable symptoms should still be checked because the fault may return.

Why might there be no symptoms if the code is stored?

An intermittent electrical fault may not be present all the time. The vehicle can run normally between occurrences, or the warning light may appear before the fault causes noticeable symptoms.

What should be checked first?

A technician should review related codes and available data, then inspect and test the fuel pump circuit and its connections. The exact checks depend on the vehicle’s model, year, and engine.

Browse Available Code Guides

Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.