P0313 — Misfire Detected With Low Fuel #

Note: The wording of this diagnostic trouble code (DTC) may vary between manufacturers. Always refer to your vehicle’s specific service documentation for precise definitions.

• P0313 – Misfire Detected With Low Fuel (Generic/SAE Standard)
• P0313 – Misfire Detected – Fuel Level Low (BMW)
• P0313 – Cylinder Misfire Detected Due to Insufficient Fuel (Ford)
• P0313 – Misfire Detected, Low Fuel Level (General Motors)

Summary of DTC P0313 #

P0313 is a diagnostic trouble code that indicates the powertrain control module (PCM)—sometimes called the engine control unit (ECU)—has detected a cylinder misfire event while the fuel level in the tank is low. In OBD-II terminology, a misfire refers to incomplete combustion in one or more cylinders, which can cause rough running, hesitation, or loss of power. This specific code links the misfire event to insufficient fuel, suggesting the misfire may be related to a near-empty tank rather than a hardware or ignition failure. While it often points to temporary issues due to low fuel, it can also highlight underlying problems with the fuel delivery system or other related components.

Common Symptoms for Code P0313 #

When your vehicle’s system logs a P0313 code, you may notice several symptoms. Some may only appear when the fuel level is low, while others could persist or worsen if the underlying issue isn’t addressed. Here’s what to look for:

• Check Engine Light (CEL) illuminated
• Rough idle or engine vibration, especially when accelerating or under load
• Hesitation or stumbling during acceleration
• Noticeable decrease in engine power
• Potential difficulty starting the engine when tank is nearly empty
• Increased exhaust emissions or a fuel smell from the tailpipe

Probable Causes for DTC P0313 #

The P0313 code is triggered when the PCM detects a misfire event during low fuel conditions. While simply running close to empty is the most common cause, other mechanical or electrical issues may contribute. Here’s a prioritized list of likely causes:

1. Extremely low fuel level in tank—fuel pickup is exposed to air intermittently, causing fuel starvation
2. Contaminants or debris in fuel tank that temporarily block the pickup when fuel is low
3. Faulty or weak fuel pump—unable to maintain proper pressure at low fuel levels
4. Fuel filter partially clogged, restricting flow when demand increases
5. Evaporative emissions (EVAP) system leaks—allowing air into the fuel line
6. Fuel level sensor inaccuracy—incorrectly reporting higher fuel than is actually present
7. Electrical issues—such as corroded or loose fuel pump wiring

Step-by-Step Diagnostic for Code P0313 #

Addressing a P0313 code requires a methodical approach. Even experienced technicians follow a troubleshooting flow to avoid missing something simple. Here’s a step-by-step guide you can use:

1. Check the fuel level gauge and physically confirm the amount of fuel in the tank—add fuel if very low.
2. Clear the code using a scan tool and perform a short drive cycle with a fuel tank at least half full. Observe if the code returns.
3. Inspect for visible leaks or damage around the fuel tank, fuel lines, and EVAP hoses.
4. Check for additional codes (such as P0171 for lean condition, or EVAP system codes) that may provide more clues.
5. Test fuel pressure at the rail with a mechanical gauge, especially under load and with low fuel levels.
6. Inspect the fuel filter for blockage or contamination.
7. Examine the fuel pump electrical connections for corrosion or loose terminals.
8. If all else fails, consider removing the fuel pump assembly for inspection of the pickup sock and tank interior.

Possible Repairs for DTC P0313 #

Once you’ve pinpointed the cause, repairs for P0313 generally align closely with the issues found during diagnosis. Here are common fixes that resolve this code:

• Refuel the vehicle—simply adding gasoline often resolves the code if the tank was too low
• Replace the fuel filter if found clogged or contaminated
• Clean or replace the fuel pump pickup sock if debris is present in the tank
• Repair or replace faulty fuel pump if pressure tests are below specification
• Repair any EVAP system leaks or damaged hoses allowing air into the fuel system
• Address inaccurate fuel level sensor readings by recalibrating or replacing the sensor
• Repair wiring or electrical faults at the fuel pump connector

Is It Safe to Drive with Code P0313? #

Limited – While it may be possible to drive for a short period with a P0313 code, it is not recommended. The code indicates your engine is misfiring due to low fuel, which can quickly escalate to stalling or even engine damage if left unaddressed. Continuing to drive with repeated misfires can also damage the catalytic converter. If you see this code, refuel as soon as possible and address any persistent symptoms immediately.

Vehicles Most Commonly Affected by Code P0313 #

While P0313 is a generic OBD-II code applicable to nearly all modern gasoline vehicles, it is most frequently reported in certain makes and models where fuel tank design or pump placement makes them susceptible to starvation at low levels. Here are some examples:

• BMW (notably E46 3 Series, E39 5 Series, and some Mini models)
• Ford (Focus, Fiesta, Fusion, Escape)
• General Motors (Chevrolet Malibu, Cruze, GMC Terrain)
• Volkswagen (Jetta, Golf, Passat)
• Hyundai/Kia (Elantra, Sonata, Forte)

Common Mistakes & Best Practices with P0313 #

Diagnosing P0313 can be deceptively simple, but several common pitfalls trip up even experienced DIYers and technicians. To avoid chasing your tail, keep these tips in mind:

• Don’t overlook the obvious: Always verify fuel level and add fuel before replacing parts.
• Never ignore additional codes: Related trouble codes can provide vital context.
• Don’t skip the fuel pressure test: A weak pump may not show symptoms until the tank is low.
• Follow up after refueling: Clear the code and monitor for return before assuming the issue is fixed.
• Best practice: Advise customers or drivers to avoid running routinely below 1/8 tank.

FAQ for Code P0313 #

Here are quick answers to questions frequently asked about P0313:

• Q: Will P0313 clear on its own after refueling?
  A: Sometimes. If the misfire was solely due to low fuel, the code may clear after a few drive cycles. However, it’s best to use a scan tool to clear it and monitor for recurrence.
• Q: Can a bad fuel pump cause P0313 even with a full tank?
  A: Yes. If the pump is weak or the pickup is damaged, starvation can occur even with adequate fuel, especially on inclines or during aggressive driving.
• Q: Should I replace spark plugs or coils when I see P0313?
  A: Not unless you also have ignition misfire codes (like P0301-P0306). P0313 is specifically linked to fuel level and delivery issues.