Fuel level genuinely very low, allowing the pump to pick up air or fuel to slosh away from the pickup; Weak fuel pump or blocked fuel pump strainer or filter reducing delivery when the tank is low; Faulty or inaccurate fuel level sender giving a low reading when the tank is not actually low, with an unrelated misfire present; Underlying ignition fault such as worn spark plugs, failing coil or damaged HT leads that shows up under marginal fuel supply; Fuel pressure regulator fault or restricted fuel line (design varies by model and engine); Injector fault or vacuum leak causing a lean misfire that becomes worse with low fuel pressure.

P0313

Misfire Detected With Low Fuel.

Generic
Powertrain
Generic code
Medium severity

How this code is built

P: SystemPowertrain
0: Defined bySAE, the same on every car
3: AreaIgnition system or misfire
13: FaultThe specific fault in that area

What it means

P0313 is the generic code for a misfire detected while the fuel level is low. The engine control unit monitors crankshaft speed for the small variations that indicate a cylinder is not firing properly. If it detects misfires while the fuel level sensor reports a very low level, it sets this code, because fuel starvation or fuel slosh may be responsible.

Symptoms

Fuel warning light on or fuel level very low when the fault appears
Engine running roughly or hesitating, especially on corners, hills or braking
Engine judder or stumbling under acceleration
Malfunction indicator lamp on, possibly flashing during a severe misfire
Engine cutting out or struggling to restart with a nearly empty tank
Reduced power

Possible causes

Fuel level genuinely very low, allowing the pump to pick up air or fuel to slosh away from the pickuplikely
Weak fuel pump or blocked fuel pump strainer or filter reducing delivery when the tank is lowpossible
Faulty or inaccurate fuel level sender giving a low reading when the tank is not actually low, with an unrelated misfire presentpossible
Underlying ignition fault such as worn spark plugs, failing coil or damaged HT leads that shows up under marginal fuel supplypossible
Fuel pressure regulator fault or restricted fuel line (design varies by model and engine)rare
Injector fault or vacuum leak causing a lean misfire that becomes worse with low fuel pressurerare

How to diagnose

Read all stored and pending codes and the freeze frame data, noting fuel level, engine load, speed and which cylinder misfired, and check for other misfire codes (P0300 to P030x)
Check how much fuel is actually in the tank and compare it with the gauge and the live fuel level data
Refuel with a good quantity of fuel, clear the code and road test to see if the misfire returns
Inspect spark plugs, coils and leads for wear, damage or heavy deposits
Check the wiring and connectors at the fuel pump and fuel level sender for corrosion, damage or poor contact
Measure fuel pressure and volume against the manufacturer specification, including with the tank low and under load
Look at live misfire counters per cylinder and short and long term fuel trims to spot a lean condition
Check for vacuum leaks and test injector operation, following the procedure for the specific engine

How to fix

Refuel the vehicle and avoid running the tank near empty
Replace the fuel pump, strainer or fuel filter if pressure or flow is low (where the filter is a serviceable item)
Repair or replace a faulty fuel level sender or its wiring
Replace worn spark plugs and any faulty ignition coils or leads
Repair vacuum leaks or replace faulty injectors or the pressure regulator as testing shows
Repair any wiring or connector faults found at the fuel pump circuit

Can I keep driving?

Medium severity

Refuel as soon as possible and avoid driving on a nearly empty tank. If the misfire continues after refuelling, or the warning light flashes, limit driving because unburnt fuel can damage the catalytic converter.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.