OBD-II trouble code
P0313: Misfire Detected With Low Fuel Level
The engine misfired while the tank was nearly empty. This is a condition report, not a component failure — and the most common correct response to it is to put fuel in the car.
Quick facts
- System
- Powertrain
- Category
- Ignition / Misfire
- Severity
- Medium severity
- Drivable
- Usually safe to drive short-term
- Repair cost range
- $0 – $1,200
- DIY difficulty
- Beginner DIY
What does P0313 mean?
P0313 exists to prevent a specific and expensive mistake. Misfire monitoring is sensitive, and a nearly empty tank produces misfires that have nothing wrong with the engine at all. When the fuel level drops far enough, the pickup screen at the bottom of the in-tank pump module can be uncovered by cornering, braking, accelerating or simply sitting on a slope. The pump then draws vapour instead of liquid, rail pressure dips for a fraction of a second, and several cylinders lean out at once. The module sees the misfire, checks the fuel level sender, finds it below the threshold, and files P0313 instead of blaming a cylinder.
Read that way, the code is doing you a favour. It is telling you that the misfire it just recorded is not admissible evidence about your ignition system, and that the correct next step is to fill the tank, clear the code, and drive normally for a few days before diagnosing anything. A very large share of P0313 cases end there.
The cases that do not end there split into two useful groups. The first is a fuel level sender reading lower than the tank actually is. Senders wear at the resistive track, and a sender stuck low will attach the low-fuel excuse to genuine misfires — which means the code is quietly suppressing information you need. If P0313 appears with a gauge showing half a tank, or appears immediately after refuelling, suspect the sender before the engine. The second is a fuel delivery problem that only exposes itself at low level: a pump losing output, a partially blocked pickup screen, or a pump module whose reservoir no longer holds fuel around the intake. Those produce P0313 at a quarter tank on a car that behaves perfectly when full, and they are real faults.
There is a maintenance point buried in this code that owners rarely hear. The fuel surrounding an in-tank electric pump is what carries heat away from it. Habitually running the tank down to the warning light shortens pump life, and a driver who sees P0313 more than once is being told something about their refuelling habits as much as about their car.
Common causes
- Driving with the fuel level at or below the low-fuel warning threshold
- Fuel pickup uncovering on gradients, hard cornering or sustained braking with a nearly empty tank
- Fuel level sender reading low, attaching the low-fuel condition to an unrelated genuine misfire
- Weak fuel pump that maintains pressure only while fully submerged
- Blocked or collapsed fuel pump pickup screen
- Damaged in-tank pump module reservoir that no longer retains fuel around the pickup
- Contaminated or water-bearing fuel drawn from the very bottom of the tank
Symptoms
- Check engine light on, sometimes flashing briefly while the misfire is active
- Stumble, surge or hesitation that appears only when the tank is low
- Rough running on hills, in long sweeping bends or under hard braking
- Engine smooths out completely within a few miles of refuelling
- Fuel gauge reading that does not match the amount of fuel the tank actually accepts
- Occasional stall at low fuel level in extreme cases
Diagnostic steps
- 1.Check the fuel level first and note it before anything else. If the tank is genuinely low, refuel to at least half, clear the code and drive for several days before diagnosing further.
- 2.Read the freeze frame and look at the recorded fuel level. That single value tells you whether the module set the code on a plausible reading or an implausible one.
- 3.Compare the fuel level percentage reported by the scan tool against the dash gauge and against the amount of fuel required to fill the tank. A sender that under-reads is a fault in its own right and it hides other faults.
- 4.Look for accompanying misfire codes. P0313 with a specific cylinder code stored alongside it points at a real cylinder problem that happened to be recorded while the tank was low.
- 5.If the fault repeats on a full tank, measure fuel pressure and volume under load. A pump that holds pressure at idle and drops it under demand is failing regardless of what the gauge reads.
- 6.Inspect the in-tank pump module and pickup screen if the vehicle has a history of being run to empty, and check for debris or a distorted reservoir.
- 7.Consider fuel quality. Water and sediment settle to the lowest point in the tank, which is exactly what the pump draws from when the level is minimal.
Repair cost
$0 – $1,200
The cheapest genuine repair for this code is a tank of fuel, and it is the right answer more often than any other. Beyond that, a diagnostic appointment is $100 to $180. A fuel level sender or sender-and-float assembly is $250 to $600 fitted, and on many vehicles it is part of the same module as the pump. Fuel pump module replacement runs $500 to $1,200 depending on whether the tank has an access panel or has to be dropped. Draining and cleaning a contaminated tank is $200 to $600.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with fuel pump replacement preselected. Adjust labor rate and vehicle category to fit your situation.
DIY vs shop
This is a beginner-friendly repair. Common hand tools, a free afternoon, and a willingness to follow a procedure are usually enough. The risk of causing a bigger problem is low if you read up on your specific vehicle first.