Cummins fault code 295
Barometric Pressure: erratic or intermittent signal
What it means
Cummins' description: Barometric Pressure - Data erratic, intermittent or incorrect.
SPN 108 is Barometric Pressure. FMI 2 means the signal is jumping around, dropping in and out, or doesn't make sense compared to other readings.
These sensors measure the air coming into the engine: intake manifold temperature, charge air cooler outlet temperature, ambient temperature, barometric pressure, humidity and air filter restriction. The ECM uses them to calculate fueling and timing.
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 one-time sensor code with normal power and temperatures.
Schedule a repair
Amber lamp, rough cold starts, or the code returns. Usually a sensor or connector. Book it so fueling stays correct.
Stop and get help
Several sensor codes at once with a stop lamp or no-start. That can point to a shared sensor supply or ECM problem. Get it diagnosed before driving.
Common causes
The sensor reading itself is out of range or the condition is real, so look at the system:
- Clogged air filter
- Dirty or blocked charge air cooler or radiator fins
- Real high intake temperature in hot weather or under heavy load
- Boost leak changing intake readings
What you can check before calling
- Check the air filter and the restriction indicator
- Clean bugs and debris from the front of the charge air cooler
- Look for unplugged or damaged connectors on intake sensors
Clearing the code without fixing the cause usually brings it right back, and on emissions systems it can restart derate timers.
Engines and sources
Listed by Cummins for: QSX 15, QSG 12. 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 Intake air and environment sensors codes
- 256 SPN 171 FMI 4
Ambient Air Temperature Sensor 1 Circuit: circuit voltage low / shorted low - 249 SPN 171 FMI 3
Ambient Air Temperature Sensor 1 Circuit: circuit voltage high / shorted high - 419 SPN 1319 FMI 2
Intake Manifold Boost Pressure Imbalance: erratic or intermittent signal - 165 SPN 1133 FMI 0
High Intake Manifold Temperature: reading above normal (most severe) - 164 SPN 1133 FMI 4
Right Bank Rear Intake Manifold Temperature Sensor Circuit Failed Low: circuit voltage low / shorted low - 163 SPN 1133 FMI 3
Right Bank Rear Intake Manifold Temperature Sensor Circuit Failed High: 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 295 mean?
Cummins fault code 295 is J1939 SPN 108 FMI 2: Barometric Pressure - Data erratic, intermittent or incorrect. In plain terms: barometric pressure: erratic or intermittent signal.
Can I keep driving with Cummins code 295?
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 295?
SPN 108 identifies the part or system (Barometric Pressure). FMI 2 describes the type of failure: erratic or intermittent signal.
What usually causes Cummins code 295?
The most common causes are: clogged air filter; dirty or blocked charge air cooler or radiator fins; real high intake temperature in hot weather or under heavy load.

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