What P064A means
Demand-controlled fuel systems drive the pump through a separate pump control module; the engine module sets the target and reads its status back.
How the engine computer detects it
P064A means this module reports an internal fault. Ford gasoline engines encode the status as a duty cycle on a monitor line – 30 % (±4 %) means internal driver fault, 20 % invalid data (P025B), no signal U0109 – and set the code after 2–5 s; Ford's 2023 diesel checks the period of the monitor signal (0–1.2 s, 0.5 s). GM's pump module sets P064A when its output stage exceeds 150 °C (302 °F) (3 of 15 samples), with the lamp after two trips; Ford gasoline stores it without the lamp. Pump output may be reduced or switched off, so low fuel pressure, stalling or a no-start can follow. A stiff, worn pump drawing high current can overheat the module.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light (GM) or stored code only (Ford gasoline)
- Hard start, stumbling or lack of power from low fuel pressure
- Stalling or no start if the pump is switched off
- Fuel pressure codes as well (e.g. P0087)
Common causes
- Pump control module faulty internally (output stage, electronics) Most likely
- Output stage overheating from a stiff or worn pump or poor module cooling Possible
- Supply or ground fault or corrosion at the module (often on frame or tank) Possible
- Disturbed monitor line, so a wrong duty cycle is read Less likely
How to diagnose P064A
- 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 control module, fuel pump, module power supply.
- 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
- 6
- Computer and output circuits
- 4A
- Specific fault
Questions drivers ask
Can I drive with code P064A?
Drive gently and only as far as you need to. The engine computer may limit power to protect the engine, so avoid highways and heavy traffic until it's fixed. If the check engine light starts flashing, pull over.
Will my car pass an emissions inspection with P064A?
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 P064A 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 P064A 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.