Finding
Every connected EV carries a TCU built around a Qualcomm or Chinese modem, and the US connected-vehicle rule is forcing separate TCU supply chains for the US and China
A telematics control unit (TCU, called a T-Box in China) packages a cellular modem, RF front-end, GNSS receiver, eSIM, an application processor, a hardware security module, flash storage and Ethernet or CAN interfaces to the vehicle. It carries telemetry, remote commands, OTA images and emergency calls. It is distinct from the in-vehicle network and from the gateway ECU, though many OEMs merge the TCU and gateway into one box.
LG Electronics is the largest TCU supplier, followed by Harman, Aumovio (Continental's former automotive group), Denso, Bosch and Marelli; in China, Huawei, Flaircomm, Gosuncn and Neusoft supply most T-Boxes. Quectel and Fibocom lead cellular modules worldwide. Under the US connected-vehicle rule, Chinese modules, modems and TCU software cannot ship in US vehicles - software from model year 2027 and hardware from model year 2030 - so Western Tier 1s are requalifying around Qualcomm chipsets and Telit Cinterion, Semtech or LG Innotek modules.
On the cloud side, data flows from a device agent (secure boot, PKI, delta OTA, store-and-forward buffering) through MQTT or HTTP ingest and time-series storage to analytics and fleet APIs. China mandates the pipeline for every new-energy vehicle: GB/T 32960 requires real-time battery and location data to flow to OEM and national monitoring platforms.
Hardware
TCU hardware blocks
A TCU combines RF hardware with compute, security and storage; each block has its own qualification cycle.
| Block | Function | Why it matters |
|---|---|---|
| Cellular modem (LTE / 5G) | Wide-area link for telemetry and OTA | Bands and carrier certification set where the vehicle can be sold; 2G and 3G sunsets stranded older units |
| RF front-end | Filters, amplifiers, antenna tuning | Sets real-world link reliability |
| GNSS receiver | Position and time base | Fleet location, geofencing, log alignment; dual-band for lane-level accuracy |
| SIM / eSIM | Carrier identity and remote provisioning | One hardware SKU for many countries and carriers |
| Application processor or MCU | Runs the telematics stack | Sets buffering, routing, diagnostics and OTA handling capacity |
| Secure element / HSM | Keys, crypto, secure boot | Root of trust for OTA integrity and authenticated telemetry |
| Flash storage | Logs and OTA staging | Update reliability depends on capacity, endurance and power-fail handling |
| Vehicle interfaces | Ethernet and CAN FD to the IVN | Ethernet increasingly common; CAN remains for diagnostics |
| Antennas | Cellular, GNSS and V2X coupling | Placement and cable loss dominate field performance |
Fleet-grade
Fleet-grade vs consumer-grade TCUs
The difference is reliability and data handling more than modem speed.
| Dimension | Consumer-oriented | Fleet-oriented |
|---|---|---|
| Telemetry volume | Moderate, periodic | High; frequent events and operational metrics |
| Reliability | Best effort | Operationally critical; store-and-forward and fault handling |
| OTA cadence | Occasional | Frequent, staged rollouts with monitoring |
| Security | Secure boot, signed updates | Stronger key management, audit trails, policy enforcement |
| Interfaces | CAN common, Ethernet growing | Ethernet, plus J1939 on trucks |
Platforms
Telematics platform landscape
The TCU is one layer; fleet value comes from the platforms that consume its data.
| Category | Examples | Where they fit |
|---|---|---|
| OEM native | Tesla, GM Envolve (OnStar), Ford Pro Telematics, Rivian Fleet, Mercedes-Benz Connect, BYD | Deep BMS and ADAS integration; OEM-controlled OTA |
| Aftermarket and fleet SaaS | Geotab, Samsara, Motive, Verizon Connect, Webfleet (Bridgestone), G7 Connect | Mixed fleets, compliance, dispatch, safety scoring |
| Regulatory platforms | China national NEV monitoring platform, Sinoiov truck platform, EU eCall PSAPs | Mandated reporting and emergency services |
| Energy and charging | Ford Pro Charging, ChargePoint, The Mobility House, Synop, Ampcontrol | Depot charging, energy cost control, V2G |
Vendors
Telematics hardware and platform vendors
TCU makers, the cellular modules and chips inside them, and the fleet platforms that use the data.
| Company | Products | HQ | Technology | Customers | Status |
|---|---|---|---|---|---|
| Actia | Telematics units for trucks, buses and off-highway | France | LTE, J1939 | Truck and bus makers | active |
| Aumovio | TCUs and connectivity modules; ex-Continental Automotive | Germany | LTE, 5G, eCall | European automakers | active: Spun off from Continental, September 2025 |
| Bosch | Connectivity control units | Germany | LTE, 5G | Not disclosed | active |
| Denso | Data communication modules | Japan | LTE, 5G | Toyota, Lexus | active |
| Desay SV | T-Box units | China | LTE, 5G, C-V2X | Chinese automakers | active |
| Ficosa (Panasonic) | TCUs and smart antennas | Spain | LTE, eCall | European automakers | active |
| Harman (Samsung) | TCUs and connectivity units | US | LTE, 5G, V2X | BMW, Stellantis and others | active |
| Huawei | T-Box units and 5G modules | China | LTE, 5G, C-V2X | Seres (AITO), Chery (Luxeed) and other Chinese automakers | active |
| LG Electronics | Telematics control units, 4G and 5G | South Korea | LTE, 5G, eCall | GM, Volkswagen Group and others | active: Largest TCU maker |
| Marelli | TCUs and connectivity | Japan, Italy | LTE, eCall | Stellantis | active: Operating under Chapter 11 since June 2025 |
| Company | Products | HQ | Technology | Customers | Status |
|---|---|---|---|---|---|
| Fibocom | Automotive LTE and 5G modules | China | LTE, 5G modules | Global TCU makers | active: Chinese connectivity hardware barred from US connected vehicles from model year 2030 |
| LG Innotek | Automotive 5G modules | South Korea | 5G, V2X modules | Not disclosed | active |
| MediaTek | Automotive modem chipsets | Taiwan | LTE, 5G chipsets | TCU makers | active |
| MeiG Smart | Automotive LTE and 5G modules | China | LTE, 5G modules | Chinese TCU makers | active |
| Qualcomm | Snapdragon Auto 4G and 5G modem platforms; Autotalks V2X acquired 2025 | US | LTE, 5G, C-V2X chipsets | Most TCU makers | active |
| Quectel | Automotive LTE and 5G modules | China | LTE, 5G, C-V2X modules | Global TCU makers | active: Largest cellular module maker; Chinese connectivity hardware barred from US connected vehicles from model year 2030 |
| Semtech (Sierra Wireless) | Automotive LTE modules | US | LTE modules | TCU makers | active |
| Telit Cinterion | Automotive LTE modules | US | LTE modules | TCU makers | active |
| Unisoc | Automotive LTE and 5G chipsets | China | LTE, 5G chipsets | Chinese module makers | active |
| Company | Products | HQ | Technology | Customers | Status |
|---|---|---|---|---|---|
| Ford Pro | Ford Pro Telematics and Ford Pro Charging | US | OEM-native fleet software | Ford fleets | active |
| G7 Connect | Truck fleet telematics and freight payments | China | Fleet SaaS | Chinese trucking fleets | active |
| Geotab | Aftermarket fleet telematics and OEM data integration | Canada | Fleet SaaS; EV battery and charging analytics | Mixed fleets; OEM-integrated data from Ford, GM, Stellantis and others | active |
| GM Envolve | OnStar-based fleet telematics | US | OEM-native fleet software | GM fleets | active |
| Motive | Fleet telematics and ELD compliance | US | Fleet SaaS | Trucking fleets | active |
| Platform Science | In-cab fleet platform; bought Trimble's transportation telematics in 2025 | US | Fleet SaaS | Truck makers and trucking fleets | active |
| Samsara | Fleet telematics, video safety and EV management | US | Fleet SaaS | Mixed fleets | active |
| Sinoiov | National road-freight monitoring platform for heavy trucks | China | Regulatory platform | Chinese heavy-truck fleets | active |
| Verizon Connect | Fleet telematics | US | Fleet SaaS | Mixed fleets | active |
| Webfleet (Bridgestone) | Fleet telematics | Netherlands | Fleet SaaS | European fleets | active |
Sources
Sources and scope
- Scope
- Telematics Control Units
- Sources
- BIS connected vehicle rule (January 2025); GB/T 32960; EU eCall Regulation; company disclosures; ElectronsX telematics dataset
- Updated
- October 2026