In modern diesel emission systems, precision is everything — and for John Deere machines using DEF (Diesel Exhaust Fluid), the head unit acts as a critical control and sensing hub. The QLS Head Unit, OEM DZ128860 (Tamerx part DZ128860TX) is not just a sensor; it's your engine’s link to properly dosing, monitoring, and diagnosing the DEF system. A failing or mis-calibrated head unit can lead to emission system faults, check engine lights, or reduced performance — none of which you want in the field.
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Measures DEF fluid level, temperature, and urea concentration, sending that data back to the ECU
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Controls dosing and feedback for your SCR (Selective Catalytic Reduction) system, enabling accurate NOx conversion
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Built to the DZ128860 OEM standard, ensuring correct fit, calibration, and compatibility with John Deere DEF systems
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Helps prevent fault codes, warning lights, or system derates triggered by incorrect sensor data
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Designed to resist vibration, thermal stress, and exposure to DEF chemistry
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Comes with a core return option and is backed by a warranty (1 million miles or 1 year)
Don’t wait for a warning light or performance drop to realize your DEF head is failing. Installing the correct OEM DZ128860 / DZ128860TX QLS Head Unit ensures your emissions loop stays accurate, your SCR system remains effective, and your machine stays clean and compliant — all without surprises in the field.