If you operate Rosenbauer fire apparatus or emergency vehicles equipped with Cummins engines, one of the most crucial—but often overlooked—components is the DEF (Diesel Exhaust Fluid) head unit. The Rosenbauer Cummins DEF Head Unit, OEM 8604149-S02, ensures your emissions system functions properly by precisely measuring, controlling, and dosing DEF into the exhaust stream. When this unit malfunctions, your vehicle is exposed to emissions faults, warning codes, and derates—none of which are acceptable in an emergency vehicle.
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Monitors DEF fluid temperature, concentration, and level—providing real-time data to the vehicle’s ECU
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Controls accurate dosing of urea into the exhaust to enable the SCR (Selective Catalytic Reduction) system to reduce NOx
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Built to OEM 8604149-S02 specifications, ensuring direct compatibility with Rosenbauer Cummins systems
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Prevents fault codes, emission warnings, and engine derates caused by bad sensor signals or failures
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Designed to handle harsh conditions: vibration, temperature swings, and exposure to DEF chemicals
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Straightforward to install—minimizing downtime and restoring system integrity quickly
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Backed by Tamerx’s one-million mile / one-year warranty when installed properly
A failing DEF head unit can compromise your emissions system at the worst possible time. With the OEM 8604149-S02 Rosenbauer Cummins DEF Head Unit, you safeguard accurate sensing and dosing, maintain regulatory compliance, and keep your emergency vehicle mission-ready. Don’t wait for a warning—you’ll want this part in your maintenance plan long before trouble strikes.























































