OBD-II trouble code
P0233: Fuel Pump Secondary Circuit Intermittent
SAE J2012 APR2002: fuel pump secondary circuit intermittent. The 1999 Ford PCED section 4 prints P0230, P0231, and P0232 and does not print this code. The printed pair is diagnosis only.
Quick facts
- System
- Powertrain
- Category
- Fuel & Air Metering
- Severity
- High severity
- Drivable
- No — stop driving until repaired
- Repair cost range
- $130 – $180 (check engine light diagnosis and testing, labor only; the fuel pump relay and the in-tank pump are outside this pair)
- DIY difficulty
- Advanced DIY
Browse every code in P0200–P0299, or start from the full code library.
What does P0233 mean?
SAE J2012 APR2002 names P0233 Fuel Pump Secondary Circuit Intermittent. Section 3.9 defines intermittent/erratic as a signal that is temporarily discontinuous, a fault too brief to count as an open or a short, or a rate of change that is excessive. P0231 is secondary low and P0232 is secondary high. Those need the fault to stay present in the command state their tests use. P0233 is the dropout that does not stay.
The 1999 Ford PCED section 4 entries that were checked define P0230, P0231, and P0232. They do not define P0233. The P0231 fail is no B+ on the fuel-pump monitor wire with the pump commanded on. The P0232 fail is voltage on that wire with the pump commanded off, from a lost ground path through the pump or from a short to power. A glitch that ends before either command state is held is not those fails. Do not copy the Mustang 4.6L resistor note or the Lightning 5.4L inertia-switch note onto this code. Those sentences are on the P0231 line.
Capture the dropout with a recording while the harness at the relay and along the pump feed is moved, key on, in park, pump commanded in the state this chart uses. Do not do that from the driver's seat on the road. When the fault is present, test short to ground and short to power separately, relay removed and pump unplugged so the motor winding is not the path. Continuity of the feed is both ends disconnected, ignition off, and again while the wire is flexed. A still check can pass the break.
RepairPal's relay average is $89–$108 and the pump average is $1,344–$1,513. Both belong to faults that test as a bad relay or an open pump, which are the P0230 and P0232 lists. They are outside this diagnosis pair. An intermittent connector was not given its own parts-and-labor total. Depressurize before a fuel fitting is opened. Support the vehicle on a lift or stands before anyone goes under it to trace the feed.
Common causes
- A relay socket or a pump-feed connector that opens when it is moved and reads intact when it is still
- A break too short for the P0231 or P0232 command-state test in this chart
- A short to ground or a short to power that is only present while the harness is flexed, tested as two results
- The 1999 Ford P0231 Mustang or Lightning notes, which that section does not attach to P0233
- A relay or a pump replaced while the recording is clean
- A primary-circuit fault, P0230, which is the relay coil rather than the secondary feed
Symptoms
- P0233 stored
- A stall or a no-start that is gone when the vehicle is sitting still in the bay
- A recorded loss of the secondary feed that a single voltage check does not repeat
- P0231 or P0232 if the same fault holds in the commanded-on or commanded-off state
- No Ford PCED paragraph to quote, because the section that was checked does not list this code
Diagnostic steps
- 1.Save the recording or the freeze frame before the code is cleared. Do not road-test with the driver watching the tool.
- 2.Confirm the code is P0233. P0231 and P0232 have Ford tests. This code was not in that section 4 list.
- 3.Key on, in park, command the pump in the state this chart uses and record the secondary feed or the FPM line while the relay socket and the feed harness are moved. Hands stay clear of the belt and the fan if the engine is running for a later check.
- 4.When the dropout is present: relay out, pump unplugged. Short to ground on the feed. Short to power on the feed. Continuity with both ends off, ignition off, while the wire is flexed. Do not let one of those stand in for the others.
- 5.A relay click without a resistance check is the incomplete test on RepairPal's relay page. Use it when the relay is actually the part being judged, and know whether the coil is switched ground or switched power.
- 6.Do not drop the tank on the strength of this code alone. If the diagram later sends you to the pump, depressurize and support the vehicle. That pump price is not the pair below.
- 7.Leave the natural-gas shutoff wording on the P0230, P0231, and P0232 paragraphs that contain it.
- 8.Verify with another recorded flex of the harness, pump commanded, not only with a cleared code.
Repair cost
$130 – $180 (check engine light diagnosis and testing, labor only; the fuel pump relay and the in-tank pump are outside this pair)
RepairPal's check engine light diagnosis and testing, updated 3 September 2026, is $125–$183 labor, rounded to $130–$180. The fuel pump relay average is $89–$108 and the fuel pump replacement average is $1,344–$1,513. Both are outside the pair. The 1999 Ford PCED section that defines those parts does not define P0233. Do not read $130–$180 as a pump.
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DIY vs shop
This is an advanced DIY job. It typically requires specialty tools, scan-tool access, lifting equipment, or careful sequencing to avoid causing new failures. Plan for extended downtime and have a backup vehicle. Most owners are better served by a shop that has done this repair before.