What This Sensor Does
The 2872140 is a thread-in coolant temperature sensor with a thermistor element. Resistance drops as coolant heat rises, and the ECM reads that change as a temperature value. That single input drives the dash gauge, fan clutch engagement, fuel timing, aftertreatment regeneration logic and the high-coolant-temperature derate and shutdown strategy.
Body is brass with a machined thread for a leak-free seal against the coolant passage. The connector is a round factory-style plug, so the harness pushes straight on with no adapter or splice. Nothing about installation should require cutting, pinning or re-terminating the existing engine harness.
Because so many control functions hang off this one signal, a drifting sensor rarely stays a gauge problem. It shows up as a fan that runs constantly, regens that start at odd times, or a truck that pulls power on a grade with no actual overheat condition present.
Why These Numbers Cross
2872140 is the headline Cummins number for this sensor on the EPA17 15L platform. Cummins 4954744 and 4954860 appear in the same interchange because they describe the same thermistor sensor with the same thread form, same round connector and the same resistance-versus-temperature behavior the ECM expects. Supersessions and packaging changes are the usual reason more than one Cummins number exists for one physical sensor.
PAI Industries 050733 is the aftermarket line number for that same sensor. PAI catalogs heavy-duty engine components against Cummins numbers, so a shop pulling 050733 off a shelf is holding the equivalent of what 2872140 covers. The number is listed here for identification only.
A cross-reference is a starting point, not a fitment promise. Confirm by reading the number stamped or printed on the sensor you are removing, or verify against your engine serial number before you order.
How It Fails And What To Check
Two failure modes dominate. The thermistor drifts, giving readings that are plausible but wrong, which is the harder one to catch. Or the element opens or shorts, which throws a coolant temperature circuit code immediately. Corrosion in the connector and coolant weeping past the threads are the other common finds.
Before you condemn the sensor, back-probe the connector and compare the signal against a known coolant temperature at the same point in the system. Inspect the pins for green corrosion and check that the harness is not chafed against the block. A wet connector shell usually means the sensor body is seeping and the leak is feeding the fault.
On install, let the engine cool, keep the sealing thread clean, and torque to your engine service specification. Do not overtighten a brass body into an aluminum or cast passage. Clear the stored codes and verify the reading climbs smoothly from ambient to operating temperature on a road test.
2872140 Cross-Reference & Interchange Numbers
These manufacturer and aftermarket numbers commonly cross-reference to 2872140. Use them to identify the part — then confirm the exact fit by VIN or the number stamped on your old unit before you order. An interchange is a starting point, not a fitment guarantee.
| Brand / Line | Cross-Reference Numbers |
|---|---|
| Cummins | 4954744, 4954860 |
| PAI Industries | 050733 |
Frequently asked questions
Will 4954744 or 4954860 work if my old sensor says 2872140?
Those Cummins numbers are listed as interchange for the same coolant temperature sensor, which is why they show up together in the cross-reference. They share the thread form, the round connector and the expected resistance signal. Confirm by matching the number on the sensor you pull out, or verify against your engine serial number before ordering.
Can a bad coolant temp sensor cause an engine derate?
Yes. The ECM uses this signal for its high-coolant-temperature protection strategy, so a sensor reading high will trigger a derate even when the engine is running at normal temperature. It can also keep the fan clutch locked in and affect regen timing. Verify actual coolant temperature independently before replacing other cooling system parts.
Does this sensor fit ISX12 engines as well as ISX15?
The listing covers Cummins ISX15, X15, QSX15 and ISX12 diesel engines in Class-8 applications including Cascadia, T680, 579, ProStar/LT, Western Star and VNL. Application coverage is broad, but it is not a guarantee for your unit. Check the number on the old sensor or confirm with your engine serial number.
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