Cummins fault code 3348
Turbocharger 1 Compressor Intake Pressure: reading below normal (most severe)
What it means
Cummins' description: Turbocharger 1 Compressor Intake Pressure - Data valid but below normal operational range - Most Severe Level.
SPN 1176 is Engine Turbocharger 1 Compressor Intake Pressure. FMI 1 means the sensor is working, but the value it reports is far below where it should be. This is the most severe 'low' level.
The turbocharger forces air into the engine. Most modern Cummins engines use a variable geometry turbo (VGT) with an electronic actuator. The ECM watches intake manifold pressure, turbo speed and compressor temperatures to control boost.
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 brief underboost code climbing a hill that clears, with normal power the rest of the time.
Schedule a repair
Noticeable power loss, black smoke, or amber lamp with a boost or VGT code. Get it checked. Boost leaks and sticky VGT actuators get worse and hurt fuel economy.
Stop and get help
Loud whine or grinding from the turbo, heavy smoke, oil pouring out of the exhaust, or a stop lamp. Shut it down. A failing turbo can feed parts or oil into the engine.
Common causes
The sensor reading itself is out of range or the condition is real, so look at the system:
- Boost leak: split charge air hose, loose clamp, cracked charge air cooler
- VGT vanes sticking from soot
- Worn or damaged turbo
- Clogged air filter or intake restriction
- Exhaust restriction from a plugged DPF
What you can check before calling
- Listen for a new hiss or whistle under load, a typical sign of a boost leak
- Check charge air hoses and clamps for oil or soot
- Check the air filter restriction indicator
- Notice whether power loss happens only under heavy load or on hills
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
- 629 SPN 1176 FMI 18
Turbocharger 1 Compressor Intake Pressure: reading below normal (moderately severe) - 741 SPN 1176 FMI 3
Turbocharger 1 Compressor Intake Pressure Circuit: circuit voltage high / shorted high - 742 SPN 1176 FMI 4
Turbocharger 1 Compressor Intake Pressure Circuit: circuit voltage low / shorted low - 743 SPN 1176 FMI 2
Turbocharger 1 Compressor Intake Pressure: erratic or intermittent signal - 3372 SPN 1176 FMI 9
Turbocharger 1 Compressor Intake Pressure: abnormal update rate - 3373 SPN 1176 FMI 19
Turbocharger 1 Compressor Intake Pressure: network data error
Related Turbo, VGT and boost codes
- 3361 SPN 102 FMI 10
Intake Manifold 1 Pressure: abnormal rate of change - 3369 SPN 1172 FMI 9
Turbocharger 1 Compressor Intake Temperature Sensor: abnormal update rate - 3616 SPN 2633 FMI 7
Engine VGT Nozzle Position: not responding / out of adjustment - 3683 SPN 1127 FMI 7
Engine Turbocharger 1 Boost Pressure: not responding / out of adjustment - 2973 SPN 102 FMI 2
Intake Manifold 1 Pressure: erratic or intermittent signal - 3917 SPN 104 FMI 18
Engine Turbocharger Lube Oil Pressure: reading below normal (moderately severe)
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 3348 mean?
Cummins fault code 3348 is J1939 SPN 1176 FMI 1: Turbocharger 1 Compressor Intake Pressure - Data valid but below normal operational range - Most Severe Level. In plain terms: turbocharger 1 compressor intake pressure: reading below normal (most severe).
Can I keep driving with Cummins code 3348?
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 3348?
SPN 1176 identifies the part or system (Engine Turbocharger 1 Compressor Intake Pressure). FMI 1 describes the type of failure: reading below normal (most severe).
What usually causes Cummins code 3348?
The most common causes are: boost leak: split charge air hose, loose clamp, cracked charge air cooler; vGT vanes sticking from soot; worn or damaged turbo.
Diesel down in the Midlands?
We work on Cummins-powered pickups, vans and medium-duty trucks across Lexington, Columbia and the Midlands, on site at your yard or roadside.