BLE TPMS Supplier Checklist: What to Verify First A practical checklist for evaluating a BLE TPMS supplier — the documents to request, the factory questions to ask, and the answers that expose a reseller.

Most evaluations start in the wrong place

The usual first move is to request a sample and a quotation. Both arrive, the sample works on the bench, and the quotation looks plausible. Then the programme starts and the questions that actually mattered were never asked.

A BLE TPMS sensor is a small, sealed, battery-powered radio device that has to survive years on a valve stem. A sample tells you almost nothing about that. What it tells you is that the supplier has at least one working unit, which is a low bar.

The useful work happens before the sample: documents, factory questions, and a small number of technical questions that a reseller cannot answer in their own words. This article sets out that checklist in the order we would use it if we were buying.

Start with the documents

Ask for these before samples. Every one of them is cheap to produce for a supplier who owns the product, and awkward for one who does not.

• A product specification sheet with protocol version, frequency band, transmit power, data rate, receiver sensitivity, supply, temperature ranges and ingress protection. Vague entries such as a bare protocol name are not a specification.
• A drawing or dimensional sheet for the sensor, including the valve interface and the tightening torque.
• A declaration of what the supplier manufactures in-house and what is bought in. Both are acceptable answers; an evasive one is not.
• A battery and handling statement — cell type, whether it is replaceable, and what happens to the sensor ID when it is replaced.
• A test report list naming which tests were performed, on what sample size, and by whom.
• A certification status statement per market. Not a logo wall. A sentence naming the approval, the market and the current status.

If a supplier cannot produce the first two, stop there. Everything else will be guesswork.

For our own BPU100, the published specification is BLE 4.1 on the 2.4 GHz band (2400–2483.5 MHz), transmit power 3 dBm at 1 Mbps, receiver sensitivity −95 dBm, a replaceable CR1632 cell that does not require re-pairing after a swap, operating range −20 °C to +80 °C, and IP68. Those are the kind of numbers a specification sheet should contain without prompting. The BPU100 product page carries the full table.

Factory verification you can do remotely

You do not always need to fly to Shenzhen, though a visit repays itself for a programme you intend to run for years. Remotely, these checks separate factories from trading offices.

Ask for a live video walkthrough of the assembly and test area, at a time you choose. A recorded clip proves nothing.

Ask who owns the tooling for the housing and the PCBA. A trading company cannot answer this precisely.

Ask for the monthly run rate, not the capacity ceiling. Any line can be quoted at its maximum. What matters is what is already committed and where your volume would fit. Our own figures are 30,000 sensors a month of capacity and more than 10,000 sets a month going into Chinese two-wheeler aftermarket programmes — two different numbers that are often conflated.

Ask how many test steps are in the line and what each one screens for. We run eight in-house test processes, including pressure calibration of every unit and RF and protocol verification. Ask for the list; a supplier who says "full quality control" is not answering.

Ask which tests the factory does not do. A factory that claims everything under one roof is either very large or not being straight with you. We do not run thermal cycling, vibration, EMC or drop testing in-house, and we say so up front, so that a project needing those can plan for a third-party laboratory from the beginning. Details are on the quality page and the factory page.

The technical questions a reseller cannot answer

These get past the sales script.

1. What is the actual Bluetooth version and band, and what is the transmit power?
2. What is the receiver sensitivity, and at what data rate?
3. What happens to the sensor ID after a battery change?
4. What happens to accuracy at the cold end of the operating range?
5. How is each unit calibrated, and is the calibration recorded per unit?
6. What are the alarm thresholds and how are they configured?
7. Is the BLE service documented well enough for our own app developer to read the sensor?
8. What is the maximum number of wheel positions the platform supports?

The last point matters if you are planning anything beyond cars and bikes. Our receiver platform supports up to 256 wheel positions, which is the kind of number a multi-trailer or fleet buyer needs early.

Answers should be specific and consistent with one another. If the specification sheet says one band and the engineer says another, that is your finding.

Commercial questions, asked in the right order

MOQ, lead time and payment terms matter, but they are the wrong opening. Ask them after the technical picture is clear, because a supplier who cannot answer the technical questions will price the commercial ones defensively.

• What is the MOQ for a standard configuration, and does it change for a branded one?
• What is frozen at order, and what can still change afterwards?
• Who owns the regulatory work for my market, and who pays for it?
• Will you sell the same branded product to another buyer in my market?

That last question tests honesty. A supplier who promises exclusivity casually has not thought about it. Treat exclusivity as a commercial arrangement to be negotiated in writing, not a courtesy.

What good and bad answers look like

Question	A useful answer	A warning sign
Frequency band	2.4 GHz ISM, 2400–2483.5 MHz, BLE 4.1	"Bluetooth, dual mode"
Battery	CR1632, replaceable, ID retained	"Long life, not serviceable"
Test steps	A named list with sample sizes	"100% inspection"
Certification	Named approvals, market by market, current status	"All certificates available"
Tooling	A named owner, in writing	"Our partner handles it"

Turning the checklist into a decision

Score each supplier on documents produced, technical answers, factory transparency and commercial clarity. A supplier who is strong on two and evasive on two is a risk; one who is consistent across all four is worth a pilot run.

Then run a paid pilot before a volume order. The pilot is where specification gaps become visible, and it is far cheaper to find them there than in a container. The supplier page explains how we scope a pilot, and the ODM page sets out what we change in-house and what we will not claim.

If you would rather have the checklist applied to your own programme than read generically, send us the vehicle, the wheel count, the market and the volume you have in mind. We will tell you which configuration fits and what would have to change.