Engine Fuel Temperature High - Warning
The CUMMINS-261 (Cummins) diesel fault code means: Engine Fuel Temperature High - Warning. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- intermediate
- Estimated cost
- $100-$600
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View pilot availability →What Are the Symptoms of CUMMINS-261?
- Engine temperature or pressure abnormal
- Possible engine derate or shutdown
- Dash warning lamp illuminated
- Gauges reading outside normal range
- Audible engine change (knock, ticking, or hiss)
- Overheat warning alarm sounding
What Causes CUMMINS-261? (Most Likely First)
- Actual mechanical issue (low oil, coolant, temp) Very Likely
- Failed sensor falsely reporting Likely
- Cooling system issue (fan, radiator, pump) Possible
- Head gasket or combustion gas leak Possible
- Obstructed airflow at charge air cooler Less Likely
Can I Still Drive with CUMMINS-261?
Yes, but fix soon. CUMMINS-261 is rated low severity. It is not an immediate stop-driving fault, but it will not clear itself — book the repair rather than ignoring it.
Frequently Asked Questions
What is Cummins fault code 261?
Cummins fault code 261 indicates: Engine Fuel Temperature High - Warning. It is a low-severity fault affecting engine mechanical condition.
Can I drive with Cummins fault code 261?
Yes, short-term driving is typically safe with fault 261, but the fault will illuminate the Check Engine Light and must be diagnosed soon. Monitor for power loss, unusual noises, or gauge changes and pull over if conditions worsen.
How much does it cost to fix Cummins fault 261?
Repair cost is approximately $100-$600 including parts, labor, and any dealer programming required. DIY repairs (sensor replacement) fall at the low end; pump, aftertreatment, or ECM work falls at the high end and usually requires INSITE diagnostic software.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose CUMMINS-261?
Verify the physical condition indicated by fault 261 -- for temperature codes, confirm with an IR thermometer; for pressure codes, use a mechanical gauge.
Compare mechanical reading to sensor reading on INSITE -- if they disagree, sensor or wiring is faulty.
Inspect the mechanical system (cooling, oil, fuel supply) for the underlying issue reported by the sensor.
Check engine fan operation, coolant level, and radiator condition for temp-related codes.
If mechanical reading confirms the fault, repair the underlying system before clearing codes -- clearing without fix will cause fault return and potential engine damage.
Sources 1
This page is built from documented references. Verify against your own service info before repair work.
- SAE J1939-73Application Layer: Diagnostics (defines the SPN/FMI fault-identifier framework)
Which Vehicles Commonly Get CUMMINS-261?
- Peterbilt 579, 567 with Cummins ISX/X15
- Kenworth T680, T880 with Cummins X15
- Ram 2500/3500 with 6.7L Cummins
- Ram 4500/5500 with 6.7L Cummins
- Freightliner M2 106 with Cummins ISL9/L9
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