Cummins fault code 5274
Engine Exhaust Back Pressure Regulator Position: erratic or intermittent signal
What it means
Cummins' description: Engine Exhaust Back Pressure Regulator Position - Data Erratic, Intermittent or Incorrect.
SPN 5625 is Engine Exhaust Back Pressure Regulator Position. FMI 2 means the signal is jumping around, dropping in and out, or doesn't make sense compared to other readings.
The engine (compression) brake and exhaust back pressure valve help slow the truck and warm up the engine and aftertreatment. The ECM controls them with solenoids and monitors their position.
What the lamp means
An amber (yellow) warning lamp means the engine can usually keep running, but the fault should be repaired soon, ideally the same day.
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.
Keep an eye on it
A brake code that set once and the engine brake still works on all settings.
Schedule a repair
The engine brake doesn't work on one or more settings, or slow warm-up. Get it fixed. You're relying more on the service brakes.
Stop and get help
Back pressure valve stuck closed (big power loss, overheating exhaust), or no engine brake on steep grades with a heavy load. Don't haul heavy until it's repaired.
Common causes
The sensor reading itself is out of range or the condition is real, so look at the system:
- Exhaust back pressure valve stuck from soot
- Engine brake out of adjustment
What you can check before calling
- Test whether the engine brake works on each setting
- Listen for the back pressure valve moving at startup
- Look for damaged wiring near the exhaust
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: Cummins Tier 4 Fault Codes. Always confirm with Cummins service information (QuickServe) for your engine serial number.
Same SPN, other failure types
Related Engine brake and exhaust back pressure codes
- 5273 SPN 649 FMI 5
Engine Exhaust Back Pressure Regulator Control Circuit: circuit open / current low - 5272 SPN 649 FMI 4
Engine Exhaust Back Pressure Regulator Control Circuit: circuit voltage low / shorted low - 5271 SPN 649 FMI 3
Engine Exhaust Back Pressure Regulator Control Circuit: circuit voltage high / shorted high - 5277 SPN 5626 FMI 13
Engine Exhaust Back Pressure Regulator: out of calibration - 4294 SPN 5097 FMI 4
Engine Brake Active Lamp: circuit voltage low / shorted low - 4293 SPN 5097 FMI 3
Engine Brake Active Lamp: circuit voltage high / shorted high
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 5274 mean?
Cummins fault code 5274 is J1939 SPN 5625 FMI 2: Engine Exhaust Back Pressure Regulator Position - Data Erratic, Intermittent or Incorrect. In plain terms: engine exhaust back pressure regulator position: erratic or intermittent signal.
Can I keep driving with Cummins code 5274?
Usually for a short time, if the engine runs normally and no other warnings are on. Get it diagnosed soon, because many amber codes lead to a derate if ignored. Look at the green, yellow and red examples on this page to judge your situation.
What is the SPN and FMI for Cummins code 5274?
SPN 5625 identifies the part or system (Engine Exhaust Back Pressure Regulator Position). FMI 2 describes the type of failure: erratic or intermittent signal.
What usually causes Cummins code 5274?
The most common causes are: exhaust back pressure valve stuck from soot; engine brake out of adjustment.
Diesel down in the Midlands?
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