Fuel Pump Secondary Circuit Intermittent
What does P0233 mean?
The P0233 code means the vehicle's onboard diagnostic system has detected: Fuel Pump Secondary Circuit Intermittent. This is a critical severity code.
Common Symptoms
- Engine stalls intermittently while driving
- Random loss of power under acceleration
- Check Engine Light comes on and off
- Difficult hot or cold starting
- Engine sputters at highway speeds
Probable Causes (Ranked by Likelihood)
- Loose or corroded fuel pump electrical connector Very High
- Intermittent fuel pump relay failure High
- Chafed or damaged fuel pump wiring harness High
- Fuel pump motor with intermittent internal fault Moderate
- PCM intermittent fuel pump driver signal Low
Step-by-Step Diagnostic Procedure
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Monitor fuel pump current draw with an amp clamp during a road test -- look for intermittent drops to zero
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Wiggle-test the fuel pump connector and wiring harness while monitoring fuel pressure for drops
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Inspect the fuel pump relay socket for burnt or corroded contacts
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Check the fuel pump wiring harness along the frame rail for chafing, heat damage, or rodent damage
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If wiring and relay test good, replace the fuel pump assembly as the internal brushes may be worn
Frequently Asked Questions
Can I drive with code P0233?
No. An intermittent fuel pump circuit is unpredictable and the engine can stall at any time, including at highway speeds. This is a serious safety concern.
Why is this code harder to diagnose than P0230?
Intermittent faults only occur under specific conditions such as heat, vibration, or load. The circuit may test perfectly in the shop, requiring extended monitoring or road testing to catch the fault.
Can rodent damage cause an intermittent fuel pump code?
Yes. Rodents commonly chew on wiring harnesses near the fuel tank. Partially damaged wires can make intermittent contact, causing this code.