Cummins fault code 3838
Estimated Engine Parasitic Losses: abnormal update rate
What it means
Cummins' description: Estimated Engine Parasitic Losses - Percent Torque - Abnormal update rate.
SPN 2978 is Estimated Engine Parasitic Losses - Percent Torque. FMI 9 means data the ECM expects to receive over the network stopped arriving or arrived too slowly. Usually a communication, power, or module problem.
This code relates to an engine control feature or configuration setting. The meaning depends on how the ECM is programmed for your truck or equipment.
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
An informational code with no lamp and the engine runs normally.
Schedule a repair
Amber lamp or the code returns with a drivability change. Have it diagnosed.
Stop and get help
Red lamp, stalling or a no-start. Don't drive it until it's diagnosed.
Common causes
The sensor reading itself is out of range or the condition is real, so look at the system:
- ECM setting or calibration doesn't match the equipment
- Condition reported by another module
What you can check before calling
- Note what the engine was doing when the code set
- Check for recent ECM programming or added equipment
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.
Related Engine control and configuration codes
- 3716 SPN 188 FMI 18
Engine Speed At Idle: reading below normal (moderately severe) - 3715 SPN 188 FMI 16
Engine Speed At Idle: reading above normal (moderately severe) - 5215 SPN 520791 FMI 2
Engine Boost Curve Selection: erratic or intermittent signal - 5291 SPN 520808 FMI 31
Engine Emergency Shutdown Switch Actived: condition exists
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 3838 mean?
Cummins fault code 3838 is J1939 SPN 2978 FMI 9: Estimated Engine Parasitic Losses - Percent Torque - Abnormal update rate. In plain terms: estimated engine parasitic losses: abnormal update rate.
Can I keep driving with Cummins code 3838?
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 3838?
SPN 2978 identifies the part or system (Estimated Engine Parasitic Losses - Percent Torque). FMI 9 describes the type of failure: abnormal update rate.
What usually causes Cummins code 3838?
The most common causes are: eCM setting or calibration doesn't match the equipment; condition reported by another module.
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.