What it means
Open circuit on the secondary fuel pump (transfer/lift pump). Pump cannot be driven.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
The secondary fuel pump, often called a transfer or lift pump, moves fuel toward the engine's main fuel system. The module monitors the pump's secondary electrical circuit and sets P023F when it detects an open circuit, so the pump may not be driven.
Common causes
Most likely first.
- Wiring break
- Pin pushed back out of connector body
- Cracked solder joint inside the module or sensor
Symptoms
- Check engine light on
- Hard start, no start, or stalling under load
- Power loss especially at high load or rpm
- Possible long cranking time
How to diagnose it
- Review freeze-frame data and fuel-system live data to see whether the fault occurred during starting, idling, or a high-load condition.
- Check whether the engine starts and whether it stalls or loses power under load, noting any long cranking time.
- Inspect the secondary pump wiring, connectors, and related fuses for breaks, loose or pushed-back pins, heat damage, or corrosion.
- With the circuit safely disabled as specified by the manufacturer, check continuity through the pump circuit and inspect connector pin fit.
- If the wiring is intact, test the secondary pump and its controlling module or circuit using the manufacturer's procedure.
Common fixes
- Reconnect a loose secondary pump connector or restore a pushed-back terminal.
- Repair a broken wire or damaged connector in the secondary pump circuit.
- Repair a failed internal module connection if testing locates the open there.
- Replace the secondary fuel pump if it fails the specified circuit and operation tests.
Can I keep driving?
A stall or no-start can leave you stranded, so avoid long trips and heavy-load driving; stop in a safe place if the engine begins to stumble or lose power. Do not continue driving if it stalls repeatedly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.