When your truck combines an International (Navistar) chassis with a Cummins engine, one of the most vital components in your emissions system is the DEF (Diesel Exhaust Fluid) head unit. The Navistar / International Cummins DEF Head Unit, built to OEM 2515900C1 specifications (Tamerx part 5410-11-FA01-4), bridges the gap between your DEF tank and the engine’s control module. If it fails or gives faulty readings, your emission system can break down—triggering codes, derates, or worse at precisely the worst time.
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Continuously measures DEF fluid level, temperature, and urea concentration, providing real-time data to your engine’s ECU
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Controls precise dosing of urea into the exhaust stream to help your SCR (Selective Catalytic Reduction) system reduce NOx properly
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Designed to drop in as a direct match to OEM tolerances (2515900C1) for International / Cummins setups
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Helps prevent fault codes, warning lights, or engine derates caused by sensor drift or incorrect inputs
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Equipped with a 40-micron filter to trap contaminants before they reach downstream components
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Built to sustain vibration, thermal cycling, and exposure to aggressive DEF chemistry
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Backed by a warranty (1,000,000 miles or 1 year) to give you peace of mind
Because the DEF head unit plays such a central role in feedback and control, it is often one of the first failure points in the emission chain. Installing the correct OEM 2515900C1 / Tamerx 5410-11-FA01-4 unit restores balance to your system, maintains compliance, and keeps your International / Cummins combination running reliably under the hood.
























































