Cummins fault code 155
Intake Manifold 1 Temperature: reading above normal (most severe)
What it means
Cummins' description: Intake Manifold 1 Temperature - Data valid but above normal operational range - Most Severe Level.
SPN 105 is Engine Intake Manifold 1 Temperature. FMI 0 means the sensor is working, but the value it reports is far above where it should be. This is the most severe 'high' level.
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
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 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: QSB 6.7, QSL 9, QSX 15, QSB 4.5, QSF 3.8, 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
- 153 SPN 105 FMI 3
Intake Manifold 1 Temperature Sensor Circuit: circuit voltage high / shorted high - 154 SPN 105 FMI 4
Intake Manifold 1 Temperature Sensor Circuit: circuit voltage low / shorted low - 436 SPN 105 FMI 2
Intake Manifold 1 Temperature: erratic or intermittent signal - 488 SPN 105 FMI 16
Intake Manifold 1 Temperature: reading above normal (moderately severe) - 2964 SPN 105 FMI 15
Intake Manifold 1 Temperature: reading above normal (least severe) - 3385 SPN 105 FMI 18
Intake Manifold 1 Temperature: reading below normal (moderately severe)
Related Intake air and environment sensors codes
- 156 SPN 1131 FMI 3
Left Bank Rear Intake Manifold Temp Sensor Circuit Failed High: circuit voltage high / shorted high - 157 SPN 1131 FMI 4
Left Bank Rear Intake Manifold Temp Sensor Circuit Failed Low: circuit voltage low / shorted low - 158 SPN 1131 FMI 0
High Intake Manifold Temp: reading above normal (most severe) - 159 SPN 1132 FMI 3
Right Bank Front Intake Manifold Temperature Sensor Circuit Failed High: circuit voltage high / shorted high - 161 SPN 1132 FMI 4
Right Bank Front Intake Manifold Temperature Sensor Circuit Failed Low: circuit voltage low / shorted low - 162 SPN 1132 FMI 0
High Intake Manifold Temperature: reading above normal (most 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 155 mean?
Cummins fault code 155 is J1939 SPN 105 FMI 0: Intake Manifold 1 Temperature - Data valid but above normal operational range - Most Severe Level. In plain terms: intake manifold 1 temperature: reading above normal (most severe).
Can I keep driving with Cummins code 155?
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 155?
SPN 105 identifies the part or system (Engine Intake Manifold 1 Temperature). FMI 0 describes the type of failure: reading above normal (most severe).
What usually causes Cummins code 155?
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.
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.