P0464: The fuel level sensor signal changes erratically or drops out in a way a real fuel level can't
Fuel level sensor circuit intermittent
Severity: Monitor
The engine runs normally; the problem is a fuel gauge that may jump around or read wrong. TroubleCodes.net rates it moderate because you could run out of fuel with the gauge still showing some. Track your mileage and get it fixed when convenient.
It gets more serious if:
- Inspect soon: Get it inspected soon if the fuel gauge becomes erratic, sticks, or reads empty or full regardless of the real level, because you could run out of fuel without warning. Track your mileage between fill-ups until it's fixed.
P0464 in short
P0464 means the fuel level sensor signal is jumping around in a way real fuel can't, usually from a worn sender track, a loose or corroded connection, or a damaged wire. The engine runs normally, but the fuel gauge may swing or read wrong. Track mileage between fill-ups and get the sender circuit checked.
The fuel level sender is a float on an arm that wipes across a resistor track. The computer expects the reading to change slowly as fuel is used, apart from sloshing.
P0464 sets when the reading changes too fast or too often. On Saab's GM-based 9-4X it sets when fuel level changes by more than 10% for 30 seconds in two of three tests, and the gauge then defaults to empty. On the Subaru-built 9-2X it needs two drive cycles in a row, and the check is whether sender resistance changes smoothly as the float moves.
A worn spot on the resistor track is the classic cause, which is why the gauge swings before the light comes on. Vehicles with saddle tanks have two senders, and both may need checking.
Most likely causes
These are general causes for this code across vehicles. None is specific to one make or model.
Cause 1: Worn fuel level sender track or wiper
Common general cause- Why it ranks here
- Saab's procedure checks for smooth resistance change across both senders, and a Hyundai dealer found both Santa Fe senders out of spec and replaced them.
- What would change this
- Likelier if resistance jumps or drops out as the float is moved slowly.
Cause 2: Loose, corroded or water-damaged connector or wiring
Common general cause- Why it ranks here
- Saab points to poor contact at the computer or meter connectors when the senders test good, and TroubleCodes.net lists corroded or damaged wiring.
- What would change this
- Likelier if the gauge flickers over bumps or the code returns after a sender replacement.
Cause 3: Fuel varnish or sulfur deposits on the sender contacts
Possible — needs testing- Why it ranks here
- TroubleCodes.net mentions varnish on some Ford senders, and AA1Car says high-sulfur fuel can corrode contacts and create dead spots.
- What would change this
- Likelier if the problem started after a particular fill-up.
Cause 4: Instrument cluster or control module fault
Possible — needs testing- Why it ranks here
- TroubleCodes.net rates a computer fault as rare.
- What would change this
- Only after the sender and wiring test good.
What to test first
Start at step 1. Each result tells you what it means and where to go next.
Step 1: Read all codes, and check for P0462 or P0463 first; watch the live fuel level reading while driving over rough road
IfP0462 or P0463 is also stored
It meansDiagnose the high or low circuit fault first.
IfReading jumps with bumps
It meansA loose connection or worn sender spot.
Step 2: Check sender resistance while moving the float slowly through its travel (both senders on saddle tanks), then check the connectors at the computer and instrument cluster
Warning:Reaching the sender means opening the fuel tank; fuel vapour is flammable. This is a job for a shop.
IfResistance jumps or drops out at points
It meansThe sender is worn.
IfSender smooth but connectors loose or corroded
It meansRepair the connection.
Points to: Loose, corroded or water-damaged connector or wiring
IfEverything tests good
It meansSuspect the cluster or control module.
Symptoms
- Check engine light
- Fuel gauge swings, sticks or reads wrong Gets more serious: stop and have it checked.
- Low fuel warning comes on with fuel in the tank
- Engine stops or won't start while the gauge still shows fuel Gets more serious: stop and have it checked.
How to fix
Step 1: Until it's fixed, refuel by distance driven rather than by the gauge.
Step 2: Ask a dealer whether your fuel level senders are covered by an emissions or extended warranty before paying for the repair.
Parts and cost context
- Fuel level sensor (sending unit):Cars with saddle tanks have two senders; a shop should test both, and the connectors, before replacing either. Labour varies; get a quote.
Labor varies by vehicle and shop; get a quote before you approve a repair.
Compare used part prices on PartPriceGuideOn your vehicle
HyundaiYour car
2007–2009 · Santa Fe
Supported by vehicle dataOwner complaints to NHTSA describe P0464 with a swinging fuel gauge; in one, a dealer found both sending units out of spec and replaced them.
Related codes
P0464 questions
Is it safe to drive with a fuel level sensor code?
The engine itself isn't affected, but the gauge can't be trusted. Fill up by distance driven rather than by the gauge, keep the tank above a quarter, and get it repaired before a long trip.
Sources and review
- P0464 Fuel Level Sensor Circuit Intermittent
- Saab 9-4X (2011) DTC P0461, P0464, P2066, P2067 or P2068 (fuel level sensor)
- Saab 9-2X (2005) 2.5i DTC P0464 Fuel Level Sensor Circuit Intermittent
- NHTSA complaint ODI 10923989: 2008 Hyundai Santa Fe, dealer found P0464 and out-of-spec fuel level senders
- Fuel Gauge Diagnosis
- Last reviewed
- Written by
- Saurabh K.
- Editorial review
- Pending
- Technician review
- Technician review pending
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