What P0464 means
The fuel level sensor is a float on a resistor track in the tank unit.
How the engine computer detects it
It is no emission part, but other monitors depend on it – the EVAP leak tests, for example, need at least 15 % fuel – so CARB requires it to be monitored and the usual exemption from the warning lamp does not apply. At GM, P0464 is a by-product of the engine-off EVAP leak test: a jump in fuel level with the vent valve closed counts as possible refuelling and aborts the test; if a following check finds no real refuelling, the jump is counted as an intermittent sensor signal (change above 10 % not stable for 30 s, 2 of 3 samples). GM sets the code with MIL on the first trip, because otherwise the leak monitor would be defeated permanently. Ford does not use P0464 and reports jumps as P0461.
Written from public technical sources and not yet checked by a mechanic. How we write these pages
Symptoms
- Check engine light on (GM after one trip)
- Fuel gauge occasionally jumps
- EVAP readiness not set
Common causes
- Loose contact or corrosion at the tank connector or sensor terminal Most likely
- Worn spots on the resistor track (wiper skipping) Most likely
- Chafed wire with intermittent contact Possible
- Car parked on a steep slope or fuel sloshing after switch-off Less likely
How to diagnose P0464
- 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 level sensor a, fuel tank unit, sensor wiring, engine control module.
- 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.
Vehicles that report P0464 most
| Vehicle | Years | Reports | Share | Median miles |
|---|---|---|---|---|
| Hyundai Santa FE | 2007–2009 | 16 | 84k |
Counts of owner complaints to the NHTSA that mention P0464 (17 in total), not failure rates: popular models get more complaints simply because more of them are on the road. Models with fewer than 3 complaints are left out.
Reading the code
- P
- Powertrain
- 0
- Generic (SAE) code
- 4
- Auxiliary emission controls
- 64
- Specific fault
Questions drivers ask
Can I drive with code P0464?
Usually yes for a short time, if the car drives normally, the temperature gauge reads normal and the check engine light is steady. If the light flashes, the engine loses power or overheats, or other warning lights come on, pull over and have it checked.
Will my car pass an emissions inspection with P0464?
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.
Often reported together
Codes that owners mention in the same NHTSA complaints as P0464. They can point to a shared cause, so it's worth checking them together.
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.