P0313
UniversalThe Powertrain Control Module (PCM) has detected an engine misfire event specifically when the fuel level in the tank is very low.
Medium SeverityThis code indicates that your vehicle's engine experienced a misfire while operating with a significantly low fuel level, suggesting that the misfire might be related to fuel delivery issues. Ignoring this can lead to rough engine operation, reduced performance, and potentially damage to emissions components like the catalytic converter.
⚠️ Before You Begin (Safety First)
Always ensure the engine is off and cool before attempting any repairs. Be extremely cautious around hot engine components and moving parts. When working with fuel system components, ensure adequate ventilation and be aware of potential fire hazards. Disconnect the battery before performing any electrical work or removing fuel lines.
Common Symptoms
- Check Engine Light illuminated
- Engine hesitation or stumbling
- Rough idling
- Reduced engine power or acceleration
- Poor fuel economy
- Engine may stall at low speeds
Common Causes
- Extremely low fuel level in the tank (often below 1/8 tank)
- Contaminated fuel or sediment drawn into the fuel system from the bottom of the tank
- Weak or failing fuel pump, especially when struggling to pick up fuel from a low tank
- Clogged fuel filter restricting fuel flow
- Failing fuel injector, exacerbated by low fuel pressure
- Worn or fouled spark plugs
- Faulty ignition coil(s)
Frequently reported on: General/Universal
Diagnostic Steps
- Immediately refuel the vehicle, ideally to at least a quarter tank or more, using high-quality fuel.
- Clear the P0313 code using an OBD-II scanner.
- Drive the vehicle under various conditions to see if the misfire returns or if the Check Engine Light illuminates again.
- If the misfire persists, inspect and consider replacing the fuel filter.
- Perform a fuel pressure test at the fuel rail to check for adequate pressure and flow.
- Inspect spark plugs for wear, fouling, or damage, and replace if necessary.
- Check ignition coils for signs of failure or arcing. If misfire is isolated to a specific cylinder, swap coil with another cylinder to see if misfire follows.
👨🔧 When to Call a Professional
If the misfire persists immediately after refueling to a healthy level and clearing the code, or if you lack the necessary diagnostic tools (e.g., a fuel pressure gauge) to test the fuel system thoroughly, it's best to consult a certified mechanic.
Commonly Asked Questions
What does the P0313 code specifically mean?
P0313 indicates that your vehicle's engine has detected a misfire, and this misfire occurred when the fuel level in the tank was significantly low. It points to a potential issue related to fuel delivery under low fuel conditions.
Can I continue driving with a P0313 code?
It is not recommended to drive for extended periods with a misfire, as it can damage the catalytic converter due to unburnt fuel entering the exhaust system. Refuel immediately and address the underlying cause as soon as possible.
Will simply adding more fuel fix the P0313 code?
Often, yes. If the misfire was caused by the fuel pump struggling to pick up fuel from a nearly empty tank, or by drawing in sediment from the bottom, refueling can resolve the issue. After refueling, clear the code and monitor for its return.
What if the P0313 code comes back after I've refueled?
If the code returns, the low fuel condition likely exposed or worsened an existing problem. This could be a weak fuel pump, a clogged fuel filter, dirty fuel injectors, or even a failing spark plug or ignition coil that couldn't cope with the slightly reduced fuel pressure from a low tank.
Does P0313 always mean my fuel pump is failing?
Not necessarily. While a weak fuel pump is a common cause, P0313 could also be triggered by a severely clogged fuel filter, contaminated fuel, or other components of the ignition system (like spark plugs or coils) that are more prone to misfiring when fuel delivery is marginally compromised by a low tank.