Cummins fault code 259
Fuel Shutoff Valve: not responding / out of adjustment
What it means
Cummins' description: Fuel Shutoff Valve - stuck open.
SPN 632 is Fuel Shutoff Valve. FMI 7 means the ECM commanded something to move or change and it didn't respond the way it should: sticking, binding, worn, or out of adjustment.
Modern Cummins engines build very high fuel pressure in a common rail that feeds the injectors. The ECM controls rail pressure with a fuel pump actuator and monitors it with a rail pressure sensor. A pressure relief valve protects the system.
What the lamp means
A red stop lamp means Cummins treats this as serious. Stop the engine as soon as you can do it safely and get it checked before running it again.
Green, yellow, red: three ways this can look
The same code can be a quick fix or a reason to shut down. Match your situation to the closest example. Cummins rates this a red stop lamp code, so if the red lamp is on, go by the red example.
Keep an eye on it
A low rail pressure code right after a filter change or running the tank low, that clears once air is bled out.
Schedule a repair
Hard starts, hesitation, power loss, or the code keeps coming back. Change the fuel filters first, then have the pressure tested.
Stop and get help
Stalling, no-start, a red stop lamp, or fuel spraying anywhere. Shut it down. High-pressure fuel leaks are a fire and injury risk.
Common causes
The sensor reading itself is out of range or the condition is real, so look at the system:
- Clogged fuel filters (the most common cause of low rail pressure)
- Air in the fuel from a loose fitting or empty tank
- Weak lift pump or restricted fuel supply
- Worn high-pressure pump
- Injector leaking back too much fuel
- Pressure relief valve opening or leaking
What you can check before calling
- Check when the fuel filters were last changed
- Make sure there's plenty of fuel in the tank
- Look for fuel leaks at the pump, rail and lines
- Notice hard starting, stalling or power loss under load
Clearing the code without fixing the cause usually brings it right back, and on emissions systems it can restart derate timers.
Engines and sources
Cummins uses the same fault code numbers across its electronic engines, including on-highway models like the ISB/B6.7, ISL/L9 and ISX/X15, though not every code applies to every engine or software level. Source: Diagnostic Fault Codes for Cummins Engines. Always confirm with Cummins service information (QuickServe) for your engine serial number.
Same SPN, other failure types
Related High-pressure fuel system codes
- 268 SPN 94 FMI 2
Fuel Pressure Sensor Circuit: erratic or intermittent signal - 271 SPN 1347 FMI 4
Engine Fuel Pump Pressurizing Assembly 1 Circuit: circuit voltage low / shorted low - 272 SPN 1347 FMI 3
Engine Fuel Pump Pressurizing Assembly 1 Circuit: circuit voltage high / shorted high - 273 SPN 1348 FMI 4
High Fuel Pressure Solenoid Valve #2 Circuit: circuit voltage low / shorted low - 274 SPN 1348 FMI 3
High Fuel Pressure Solenoid Valve #2 Circuit: circuit voltage high / shorted high - 275 SPN 1347 FMI 7
Fuel Pumping Element #1 (Front): not responding / out of adjustment
Look up another code
Cummins fault code (like 1922), J1939 SPN and FMI (like SPN 3251 FMI 0), or an OBD-II code (like P0420).
Questions
What does Cummins fault code 259 mean?
Cummins fault code 259 is J1939 SPN 632 FMI 7: Fuel Shutoff Valve - stuck open. In plain terms: fuel shutoff valve: not responding / out of adjustment.
Can I keep driving with Cummins code 259?
No. Cummins assigns this code a red stop lamp. Stop the engine as soon as it's safe and have it checked before running it again. Look at the green, yellow and red examples on this page to judge your situation.
What is the SPN and FMI for Cummins code 259?
SPN 632 identifies the part or system (Fuel Shutoff Valve). FMI 7 describes the type of failure: not responding / out of adjustment.
What usually causes Cummins code 259?
The most common causes are: clogged fuel filters (the most common cause of low rail pressure); air in the fuel from a loose fitting or empty tank; weak lift pump or restricted fuel supply.
Diesel down in the Midlands?
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