What this page is
This page is for OEM teams sourcing a commercial vehicle sensor manufacturer in China. It covers the tyre-pressure (TPMS) sensors and receivers, rain-light sensors, fuel-level senders and audible annunciators we build, and how each one is specified, validated and produced. The starting point is always your wheel layout, vehicle network and mounting needs rather than a fixed catalogue part number.
The detail below is the qualification pack we share with engineering teams specifying a fleet TPMS rollout, a cab rain-light upgrade or a tank-level instrument. For the engineering background on how tyre-pressure monitoring works and how to write the specification, see the heavy-truck TPMS buyer guide.
Who Youlai is
Changsha Youlai Electronic Technology Co., Ltd. is an IATF 16949 certified OEM electronics manufacturer based in Changsha, Hunan, China. We supply vehicle electronics — sensors and switch panels, body control, power distribution and displays — to commercial-vehicle and construction-machinery OEMs including SANY, XCMG, ZOOMLION, SINOTRUK, YUTONG and BYD. The full named list is on the About page.
The quality system is certified to IATF 16949. Environmental and OH&S system certificates (ISO 14001 / ISO 45001) are shared as current PDFs during qualification — see the OEM sourcing guide for what to verify.
What we make in vehicle sensors
The sensor range covers the measurements a commercial-vehicle programme reads off the wheels, the cab glass and the tanks. The sensor platforms below are published designs we build to your OEM specification.
| Model | Measures | Supply | Link / output | Sealing |
|---|---|---|---|---|
| YDK‑902 | Tyre pressure, acceleration and temperature; valve-stem mount; 5–8 year battery | 2.5–3.3 V | 433.92 MHz frequency-hopping RF | IP66 |
| YDK‑903 | Tyre pressure, acceleration and temperature; clamp-mount with whip antenna; 5–8 year battery | 2.5–3.3 V | 433.92 MHz frequency-hopping RF | IP66 |
| EBX‑957 | TPMS receiver for both wheel sensors | 18–32 VDC | 1 × CAN; Deutsch DT06-4S | IP67 |
| CGQ‑024A | Light and rain on the glass, for automatic headlamps and wipers | 12 VDC and 24 VDC rated | CAN; Deutsch DT04-4P | — |
| CGQ‑012A | Ambient light | 4.5–5.5 V | Low-level output on pin 2; Yazaki 7283-8660 | IP53 |
The YDK-903 is for mining, special-trailer and drop-centre wheels whose geometry does not accept a valve-stem sensor. Fuel-level senders and buzzers / annunciators are quoted through the same OEM workflow; their mounting, signal interface and range are configured per programme.
The full Switches & Sensors catalogue, including the model matrix, is on the Switches and Sensors overview page; buyers consolidating a whole program can also source body control, power distribution, displays and switch panels from the same supplier across the four product families.
Lines and test equipment
The Changsha factory runs three SMT lines (solder-paste print, SPI, JUKI placement, multi-zone reflow and AOI), one THT auto-flow line with wave soldering, and four assembly lines. Every assembly line ends in a functional test station. In-circuit testing is done on the ICT station. Annual capacity across the factory is 1.5 million sets.
These rigs belong to the Changsha lab, which validates models across the four product families.
| In-house rig | What it tests |
|---|---|
| Water-spray chamber | IPX water ingress |
| Dust chamber | IP5X / IP6X dust ingress |
| Salt-spray chamber | Accelerated corrosion |
| Temperature and humidity chamber | Programmable temperature and humidity profiling |
| Climate cycling chamber | Long-form humidity and temperature cycling |
| Thermal-shock chamber | Hot–cold step change |
| Aging chamber | Sustained burn-in at elevated temperature |
| Vibration and shock | Multi-axis vibration table; drop and bump |
| ESD generator | ESD immunity per IEC 61000-4-2 |
| ISO 7637 simulator | Supply-line transient immunity |
| Surge generator | Lightning surge immunity |
| Hipot tester | Dielectric withstand and insulation resistance |
| HIL simulation rig | Hardware-in-the-loop vehicle-network simulation |
In-house EMC work is pre-compliance. Formal EMC certification, when a programme requires it, is at accredited third-party laboratories. The quality page has photos of the lines and of the rigs it shows. Dust ingress, vibration and mechanical shock are described on the environmental and EMC page.
How a programme starts
- Briefing. These help if you already have them: target vehicle / machine, expected annual volume, the measurement and sensor list (TPMS, rain-light, fuel-level, buzzer), wheel population and rim type for TPMS, working voltage where a receiver is involved (12 V / 24 V), reporting protocol (CAN 2.0 / CAN-FD / J1939), mounting constraint, IP rating, temperature range and connector preference.
- Selection or custom. We propose the closest standard platform. If your program needs a different mounting style, sealing class, RF ID scheme, CAN map or connector, we quote a custom variant on the same platform rather than starting from zero. Where the requirement does not map onto any existing platform, we scope it as a new design instead of forcing a fit.
- RF protocol & receiver pairing. For TPMS we agree early on the wheel-side sensor style (valve-stem, clamp-mount or both), the ID-coding scheme and which receiver the wheel sensors pair to — the Youlai EBX-957 or an OEM-equivalent. This decision drives commissioning more than any hardware line item.
- Sample & validation. Engineering samples for standard variants, with validation supported by our in-house environmental lab and EMC pre-compliance — temperature and vibration, sealing checks, battery-life modelling on the wheel sensors, and a full RF round-trip against the receiver and your body-control simulator.
- Mass production. On the lines above, with in-process inspection, an end-of-line RF and CAN-message test and traceable batch records. The drawing package, BOM and quality-system documentation are released at the milestones agreed with you. Region-specific approvals such as e-Mark / ECE and SASO, and radio approvals such as FCC, are available upon project requirement and confirmed per destination market.
Why programmes pick this supplier
- Engineering-led, not catalogue-only. Because we own the housing, the PCBA and the RF and CAN integration, a custom mounting style, ID-coding scheme or reporting map is something we quote as part of the normal workflow rather than treat as a special case.
- RF and protocol depth. We work with the 433.92 MHz frequency-hopping TPMS link and single-CAN receiver reporting day to day; the heavy-truck TPMS guide walks through how a wheel sensor reaches the cluster.
- Mixed-wheel coverage. Valve-stem and clamp-mount sensors speak one protocol to one in-cab receiver, so a fleet with non-standard rims does not need a second monitoring system.
- Sealing range. The wheel sensors are IP66 for years of in-wheel service and the receiver is IP67; we document the design rationale behind the IP65 / IP67 enclosures rather than leave it assumed.
- Full product-family coverage. Buyers consolidating the electronics side of a program can take sensors, switch panels, body control and power distribution from one supplier across the four product families.
- Direct contact. Sales mobile +86 134 6767 4786, also on WhatsApp.
Get a quote moving
Email sales@yltronics.com or message us on WhatsApp. A sensor list, the vehicle or machine spec, the wheel population and the bus matrix help if you already have them. Typical reply within one business day. NDA on request.