Overview
The YDK-902 sits inside the wheel, bolted to the valve stem with an M5 stainless retaining screw. It reads tyre pressure, in-wheel acceleration and tyre-cavity temperature, and broadcasts the readings on a 433.92 MHz frequency-hopping RF link that the in-cab receiver picks up — typically the Youlai EBX-957 TPMS receiver, or an OEM-equivalent receiver.
The valve-stem mount is the standard route for trucks, buses, trailers and multi-axle commercial vehicles, where the after-market screw-cap style is not robust enough for the duty cycle. Once installed, the sensor is wheel-balanced as part of the wheel; nothing protrudes outside the rim.
What it senses
- Pressure. Tyre cavity pressure, the primary TPMS signal — reported continuously while the wheel is rotating, with low-rate watchdog reports while parked.
- Acceleration. Used as a wake-up trigger and as a "wheel rotating" qualifier, so the sensor stays in deep sleep when the truck is parked and saves battery.
- Temperature. Tyre cavity temperature — used in the receiver's pressure-correction algorithm and to flag overheating brakes / under-inflated tyres on long descents.
Mechanical & battery life
The sealed housing is IP66, with main body and rear cover moulded in PA66-GF30 (30% glass-filled polyamide) over an FR-4 PCBA. Mounting hardware is an M5 stainless drop-resistant screw — the screw geometry resists fall-out under in-wheel vibration. With a typical commercial-vehicle duty cycle (engine on roughly 8–12 h/day, sensor in deep sleep otherwise), the replaceable CR2032-class cell powers the YDK-902 for 5–8 years before service replacement is recommended.
RF link & receiver pairing
The 433.92 MHz link is frequency-hopping with ±0.5 MHz spread, and transmits at −10 dBm. Pair the YDK-902 with the Youlai EBX-957 TPMS receiver for a complete wheel-to-cab system, or specify your OEM-preferred receiver at quotation. RF protocol details and ID-coding are confirmed against your fleet plan.
Manufacturing & testing
Built under IATF 16949 with APQP project planning and a PPAP package available for OEM programmes. Every sensor goes through end-of-line pressure, RF transmit and battery-current checks before packaging. Cold-chamber and high-altitude validation is run on a sample basis in our in-house lab when the programme requires it.
Choosing the YDK-902: valve-stem, clamp-mount, and the receiver
The YDK-902 is the valve-stem sensor in the Youlai heavy-truck TPMS family, and it is the default wherever the rim takes a conventional metal valve — the standard case on trucks, buses, trailers and multi-axle commercial vehicles. It sits on the valve stem with no external antenna, is wheel-balanced as part of the wheel, and nothing protrudes outside the rim. For a fleet on standard rims, this is the sensor to specify.
Where a rim will not accept a valve-stem sensor — heavy mining wheels with non-standard valve geometry, special trailer rims, or drop-centre wheels whose cooling fins foul the sensor body — the clamp-mount YDK-903 is the complementary variant: same 433.92 MHz frequency-hopping protocol, same pressure / acceleration / temperature payload and the same 5–8 year battery target, but clamped inside the rim with an external whip antenna to clear the rim-metal shadow. Because both variants speak one protocol to one receiver, a mixed wheel population runs as a single system: pair either sensor with the EBX-957 TPMS receiver, which decodes the per-wheel IDs and publishes pressure and temperature on CAN to the cluster or BCM. For the wheel-count, pressure-threshold and receiver-interface checklist that goes into a fleet specification, see the heavy-truck TPMS buyer guide.
How to ask
The YDK-902 belongs to the Switches & Sensors family. To request the sensor-to-receiver pairing protocol, the wheel-installation drawing or a multi-axle fleet-grade configuration, please use the contact page with your target vehicle programme, expected annual volume and key technical requirements (number of axles, OEM receiver if any, wheel size, pressure range). Drawings welcome.
