Fuel injector failure, including an injector stuck open (both sources). Leaking fuel lines, common rail, or a leak anywhere in the high-pressure circuit (both sources). Fuel pressure regulator failure (both sources). Fuel pressure sensor malfunction (OBD-Codes.com). Plugged fuel filter, or a failing fuel pump or lift pump (OBD-Codes.com). Injection pump leak, fuel control actuator failure, fuel pressure limiting valve or cascade overflow valve problems (OBD-Codes.com). Fuel heater stuck on or a failed fuel temperature sensor (OBD-Codes.com). Wiring issues: corroded or loose connectors, or a short in the injector harness (both sources). Engine computer (ECM/PCM) failure (both sources).

Replace a leaking or stuck-open injector, and change oil and filter if fuel got into the oil (RepairPal lists fuel injector replacement as its common repair). Repair a leaking fuel line, rail fitting or injection pump. Replace a plugged fuel filter or a failing lift pump. Replace a faulty fuel pressure sensor or pressure regulator only after confirming it with testing. Repair damaged wiring or connectors; replace or reprogram the engine computer only after everything else checks out.

P0093⛽ Fuel / fuel pressureStop and fix promptly

P0093: Fuel System Large Leak Detected (Meaning, Causes, Fixes)

Q: What does P0093 mean?

P0093 means the engine computer saw a sudden large drop in fuel pressure that it reads as a large fuel leak. It is most often seen on common-rail diesels such as the Ford 6.7 Power Stroke, Duramax and Isuzu trucks. A leaking injector, line or rail, a faulty fuel pressure sensor, a plugged fuel filter, a weak lift pump, a bad pressure regulator, or wiring trouble can cause it, so look for real leaks and fuel in the oil before replacing parts. The engine computer (ECM or PCM) watches fuel pressure from the high-pressure pump to the injectors whenever the engine runs. OBD-Codes.com explains that P0093 sets when the computer senses a sudden large drop in fuel pressure, which can come from an internal leak (such as an injector stuck open), an external leak, or a faulty sensor signal. On a diesel, it says the computer then enters fail-safe mode, suspends the injection pump and allows about one minute to pull over before shutting the engine down, staying in fail-safe until the key is turned off. RepairPal describes the same code more generally: the PCM uses several sensors to keep fuel pressure constant and sets P0093 when one of them detects a pressure drop. P0093 is a generic code that applies to all OBD2 vehicles. P0094 is the small-leak version.

Q: Can I keep driving with P0093?

Stop and fix promptly. RepairPal puts P0093 in its urgent category, meaning action is needed right away because it can cause severe damage or put the people in the car at risk, and it lists stalling as a symptom. OBD-Codes.com says that on a diesel the engine computer goes into fail-safe mode and can shut the engine down within about a minute, and that the engine could shut down at any time or speed. Pull over safely, do not keep restarting and driving it, and have it towed if needed. Diesel high-pressure fuel systems run thousands of PSI (OBD-Codes.com cites 4,500 to 30,000 PSI), so never touch or loosen fuel lines with the engine running, and if engine oil smells of fuel, OBD-Codes.com says not to start the engine again until the oil and filter are changed.

Reviewed 2026-10-24 · Based on 2 cited source(s)

What P0093 means

The engine computer (ECM or PCM) watches fuel pressure from the high-pressure pump to the injectors whenever the engine runs. OBD-Codes.com explains that P0093 sets when the computer senses a sudden large drop in fuel pressure, which can come from an internal leak (such as an injector stuck open), an external leak, or a faulty sensor signal. On a diesel, it says the computer then enters fail-safe mode, suspends the injection pump and allows about one minute to pull over before shutting the engine down, staying in fail-safe until the key is turned off. RepairPal describes the same code more generally: the PCM uses several sensors to keep fuel pressure constant and sets P0093 when one of them detects a pressure drop. P0093 is a generic code that applies to all OBD2 vehicles. P0094 is the small-leak version.

Severity: can I keep driving?

Stop and fix promptly

RepairPal puts P0093 in its urgent category, meaning action is needed right away because it can cause severe damage or put the people in the car at risk, and it lists stalling as a symptom. OBD-Codes.com says that on a diesel the engine computer goes into fail-safe mode and can shut the engine down within about a minute, and that the engine could shut down at any time or speed. Pull over safely, do not keep restarting and driving it, and have it towed if needed. Diesel high-pressure fuel systems run thousands of PSI (OBD-Codes.com cites 4,500 to 30,000 PSI), so never touch or loosen fuel lines with the engine running, and if engine oil smells of fuel, OBD-Codes.com says not to start the engine again until the oil and filter are changed.

Common symptoms

Check engine light on (both sources)
Decreased engine performance or a large loss of power above idle (both sources)
Engine may stall; on diesels OBD-Codes.com says the engine enters fail-safe mode and shuts down within about a minute
Increased fuel consumption (RepairPal)

Likely causes

Roughly most to least common, based on the sources below. Your vehicle may differ.

Fuel injector failure, including an injector stuck open (both sources)
Leaking fuel lines, common rail, or a leak anywhere in the high-pressure circuit (both sources)
Fuel pressure regulator failure (both sources)
Fuel pressure sensor malfunction (OBD-Codes.com)
Plugged fuel filter, or a failing fuel pump or lift pump (OBD-Codes.com)
Injection pump leak, fuel control actuator failure, fuel pressure limiting valve or cascade overflow valve problems (OBD-Codes.com)
Fuel heater stuck on or a failed fuel temperature sensor (OBD-Codes.com)
Wiring issues: corroded or loose connectors, or a short in the injector harness (both sources)
Engine computer (ECM/PCM) failure (both sources)

Diagnostic steps you can do

⚠ Before you start

Work on a cool engine, parked on level ground with the parking brake set. Never work under a car supported only by a jack.

With the engine off, walk around the vehicle and look for obvious fuel leaks between the tank and the engine (OBD-Codes.com).
Check the engine oil level and smell. If the level has risen and it smells strongly of fuel, an injector has likely failed open; OBD-Codes.com says not to start the engine again until the oil and filter are changed.
Under the hood, follow the lines from the injection pump to the rail and look at each injector for signs of leaks (OBD-Codes.com).
Unplug the fuel pressure sensor connector and look for fuel inside it; OBD-Codes.com says a failed sensor can let fuel up into the connector.
Check when the fuel filter was last changed, since a plugged filter can drop fuel volume enough to set the code (OBD-Codes.com).
Inspect sensor and injector wiring for missing insulation, corrosion or loose connections, then look up technical service bulletins (TSBs) and your diesel warranty, which often covers injectors for many years (OBD-Codes.com).

Typical fixes

Replace a leaking or stuck-open injector, and change oil and filter if fuel got into the oil (RepairPal lists fuel injector replacement as its common repair)
Repair a leaking fuel line, rail fitting or injection pump
Replace a plugged fuel filter or a failing lift pump
Replace a faulty fuel pressure sensor or pressure regulator only after confirming it with testing
Repair damaged wiring or connectors; replace or reprogram the engine computer only after everything else checks out

Repair costs vary widely by vehicle, region, parts brand and shop, so we don't quote prices. Get a written estimate after diagnosis.

🛠 When to call a pro

Checking actual high-side fuel pressure and engine computer operation needs special tools; OBD-Codes.com says the dealer is the next step if no obvious problem is found
Injector, rail and high-pressure pump work on common-rail diesels involves extreme pressure and requires OEM seals and gaskets (OBD-Codes.com)
Warranty or TSB repairs on diesel injectors and pumps go through the dealer

Where to buy

Plain search links. Always match parts to your exact year, make, model and engine.

OBD2 scanners on Amazon Parts at Advance Auto Parts catalog at RockAuto

FAQs

Can I keep driving with P0093?

It is not a good idea. RepairPal rates it urgent, and OBD-Codes.com says a diesel may shut down within a minute of the code setting and could stall at any speed. The problem will not fix itself, so find the cause before driving again.

Does P0093 only happen on diesels?

P0093 is a generic OBD2 code, but OBD-Codes.com writes about it in terms of diesel high-pressure systems, and most search interest is for diesel trucks like the Ford 6.7 Power Stroke, Duramax and Isuzu NPR. RepairPal describes it without mentioning diesel.

Do the sources agree on the cause?

Mostly. Both name injectors, leaking lines, the pressure regulator, wiring and the engine computer. OBD-Codes.com adds a much longer list, including the pressure sensor, plugged fuel filter, lift pump and pressure limiting valve, and notes a bad sensor signal alone can set it. RepairPal lists injector replacement as the common repair, while OBD-Codes.com puts a leak check, fuel-in-oil check and filter check first.

Sources

Last reviewed 2026-10-24. Code definitions and repair steps can vary by manufacturer. Confirm with your vehicle's service information.