What it means
The control module detected a large leak or loss of pressure in the fuel system. The code does not confirm a visible fuel leak.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
- The engine or gearbox may go into limp mode
How it works
The fuel system supplies pressurized fuel to the engine, and the control module uses pressure data to detect a substantial loss. P0093 is set when the detected pressure loss meets the system's large-leak threshold; it signals a major loss of pressure but does not prove that fuel is visibly escaping.
Common causes
Most likely first.
- Fuel line cracked or fitting loose
- Injector O-ring failed
Symptoms
- Check engine light on
- Loss of power or engine hesitation
- Hard starting or stalling
- Fuel odor may be present
How to diagnose it
- Check freeze-frame data and fuel-pressure readings to confirm when pressure dropped and whether the loss occurred during starting, idling, or load.
- With the engine off, inspect accessible fuel lines and fittings for wetness, damage, looseness, or a strong fuel smell.
- Check around the injectors for signs of fuel at the injector seals or O-rings, taking care not to work near hot or running parts.
- If no leak is visible, have fuel pressure and pressure retention tested against the manufacturer's specification to locate an internal or hidden loss.
- If pressure testing does not confirm a leak, verify the pressure sensor readings and related wiring before replacing fuel-system parts.
Common fixes
- Tighten or replace a leaking fuel-line fitting.
- Replace a cracked or damaged fuel line.
- Replace a failed injector O-ring or seal.
- Repair a confirmed pressure-sensor or wiring fault if the apparent pressure loss is not real.
Can I keep driving?
Do not drive if you smell fuel or see wet fuel; shut the engine off and keep away from ignition sources. Even without a visible leak, power loss or stalling can make driving unsafe, so arrange prompt inspection.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.