NOx Sensor DZ110621

BG 990675 (OE DZ110621): function on the vehicle

NOx Sensor DZ110621 is supplied by BEST GROWTH under part number 990675, cross-referenced to OE DZ110621, as a direct-fit aftermarket nox sensors. In service it measures nitrogen-oxide concentration and residual oxygen in the exhaust stream and reports both values to the aftertreatment controller over the vehicle data bus. Upstream and downstream readings together set DEF dosing quantity and score SCR conversion efficiency.

BG 990675 is built to the position defined by its OE application on a 24V electrical system in agricultural machinery service on the platform from John Deere. Position, calibration and connector layout are part of the specification, so a part that physically fits is not automatically the correct part.

Cable length and connector keying are part of the specification. A cell with correct electrical output but the wrong lead length will not route to the OE bracket.

Fitment for John Deere and OE cross reference

BG 990675 replaces 1 OE reference: DZ110621. Always confirm the number printed on the removed part, including any supersession issued by the vehicle manufacturer.

Recorded vehicle coverage for 990675 includes John Deere, typically on Combine W540 / W550 / W650. Coverage lists are a starting point for identification, not a substitute for checking the OE number on the vehicle.

Quote the number printed on your part with the engine code when you enquire; a single-reference part is the most common source of ordering errors when a platform received a mid-life update.

Symptoms that lead to replacing DZ110621

These complaints bring a vehicle in with the John Deere nox sensors under suspicion. None of them prove BG 990675 has failed on its own, which is why the checks below matter before a replacement is ordered.

• dosing shut-down after a few minutes of steady-state running
• upstream and downstream values reading almost identically under load
• intermittent fault that clears after the engine cools and returns when hot
• SCR efficiency below threshold or NOx-signal-implausible fault codes
• DEF over-consumption with no visible leak

Checks before fitting BG 990675

Aftertreatment faults are usually system faults. Working through these checks prevents a repeat failure after the new nox sensors is fitted.

• Read the sensor's own dew-point release time — a cell that never heats is a supply or module fault.
• Verify DEF concentration with a refractometer before blaming the measuring cell.
• Check for a pending software or parameter update for the sensor control module on that platform.
• After fitting, run the manufacturer's adaptation or relearn so stored efficiency counters reset.
• Compare upstream and downstream NOx readings warmed and under load — idle values prove nothing.

Quality, packaging and ordering 990675

BG 990675 is manufactured and tested to aftermarket replacement standards, with electrical, leakage and functional testing carried out before packing on the 24V specification. Bulk and retail packaging, private-label cartons and customer-specific labelling are available for distributors and workshop groups.

Send OE DZ110621 or the number printed on your part, the engine code and the vehicle identification number with your enquiry, and our technical team will confirm the correct reference, current stock position and lead time before you commit to an order.

Frequently asked questions

Does BG 990675 replace OE DZ110621?

Yes. BG 990675 is listed against DZ110621. Confirm the number printed on the removed part and any manufacturer supersession before ordering.

Which vehicles does BG 990675 fit?

Recorded coverage includes John Deere. It is supplied as a direct-fit aftermarket nox sensors on 24V systems. Adaptation, reset or relearn procedures required by the vehicle manufacturer still apply after installation.

Does this fault code always mean the nox sensors has failed?

No. Exhaust leaks, wiring and connector damage, reductant quality, dosing performance and upstream engine faults can all produce the same codes. Validate those inputs before replacing BG 990675.