CAN FD in SAE J1939 for Heavy-Duty Vehicles: Market Adoption Report

Introduction

SAE J1939 is the dominant in-vehicle network protocol for medium and heavy-duty vehicles, traditionally running on Classical CAN at 250 kbps (or 500 kbps) with 8-byte frames. As modern trucks and buses integrate more electronics – from advanced engine controls to ADAS sensors – the bandwidth limitations of classical J1939 networks have become a bottleneck. In response, the SAE released new standards (J1939-17 physical layer and J1939-22 data link) in 2021-2022 that allow J1939 to operate over CAN FD (Flexible Data Rate). CAN FD raises the data phase speed (e.g. to 2 Mbit/s in J1939-22) and expands payloads to 64 bytes, roughly quadrupling throughput for J1939 messages. This report examines how the industry is implementing J1939 over CAN FD – focusing not on technical specs but on real product examples, adoption by OEMs and fleets, industry viewpoints on CAN FD vs. Ethernet, market trends, and implementation challenges.

Product Implementations Supporting J1939 over CAN FD

Multiple vehicle network products now support J1939 over CAN FD, indicating early implementation in the field. Examples include:

Telematics and Gateway Devices: Dedicated telematics control units and gateways for heavy vehicles now offer CAN FD compatibility. For instance, the iWave Telematics Gateway supports four CAN bus interfaces including CAN FD, and is marketed for heavy-duty trucks, off-road machines, and other rugged applications. This device logs J1939 CAN data and can transmit it over 4G/Wi-Fi for predictive maintenance and fleet monitoring.
https://www.iwavesystems.com/product/telematics-gateway/
CAN Bus Data Loggers: Modern CAN loggers used in fleet telematics and R&D now include CAN FD support for J1939. For example, CSS Electronics’ CANedge data logger provides two CAN/FD channels and is explicitly advertised for heavy-duty J1939 fleet management. These loggers let OEM engineers and fleet managers capture high-speed J1939-FD data (e.g. high-frequency engine or battery data) for analysis and diagnostics.
https://www.iwavesystems.com/product/telematics-gateway/
Vehicle Diagnostic Interfaces: The heavy-duty service and diagnostics industry is updating tools to handle CAN FD on J1939. NEXIQ’s latest USB-Link 3 diagnostic adapter (a de facto standard interface in North American fleets) supports J1939 FD protocols in addition to classic J1939. It can automatically detect 250K/500K/1M baud CAN FD on the 9-pin Deutsch vehicle connector, ensuring that fleet service technicians can communicate with new CAN FD-equipped vehicles.
https://www.nexiq.com/Shopping/Product_GEX.aspx?ProductNumber=NQ121054
Similarly, other RP1210 interfaces (e.g. by DG Technologies, Cummins, etc.) now advertise CAN FD capability to remain compatible with next-gen trucks.
https://heavydutytruckdiagnostics.com/store/Nexiq-USB-Link-2-124034-WIFI-Panasonic-Toughbook-Upgraded-124032-p464708158/
ECUs and Controllers: Tier-1 suppliers are rolling out controllers with CAN FD-enabled J1939 stacks. For instance, high-performance sensors and ECUs used in trucks increasingly feature both CAN FD and Ethernet. ACEINNA’s new automotive-grade IMU330RA inertial measurement unit is a recent example – it provides a CAN FD interface (alongside 1000Base-T1 Ethernet) for integration into vehicle systems. This indicates that subsystems like stability control, advanced braking, or autonomous driving modules can utilize CAN FD to send high-rate data (e.g. 1000 Hz updates from an IMU) over the J1939 network when needed.
https://www.oemoffhighway.com/electronics/smart-systems/automated-systems/product/22865097/aceinna-inc-highperformance-inertial-measurement-unit
Development Tools: Although not installed in vehicles, it’s noteworthy that tools like Vector CANalyzer.J1939 and PEAK PCAN support J1939 over CAN FD. This has enabled OEMs and suppliers to develop and test J1939-22 networks. Kvaser, a CAN interface manufacturer involved in the J1939 committee, also updated its product line to ensure its CAN adapters and dataloggers fully support J1939 FD frames.

These examples demonstrate that the ecosystem (from onboard ECUs to offboard diagnostic and logging tools) is being upgraded for CAN FD. In practice, early implementations often involve adding a new CAN FD bus alongside existing CAN buses – for instance, a telematics unit might connect to both a classic 250 kbps J1939 network and a new high-speed J1939-FD network in the same vehicle.

Adoption by Truck OEMs and Fleet Operators

Truck Manufacturers (OEMs) have begun adopting CAN FD for J1939 in new vehicle platforms, but the rollout is gradual. The official J1939-22 standard for CAN FD was published in March 2021, and since then the heavy-duty trucking industry has signaled a transition from classic CAN to CAN FD. In fact, this transition is already underway: according to engineers on the SAE Truck Bus Network Committee, the heavy trucking industry “is now moving to CAN FD” following the release of J1939-22. Initial deployments are expected in high-data-demand subsystems or new models where the benefits are immediate. For example, next-generation engines with extensive emissions sensors or hybrid/electric powertrains (which produce large volumes of battery/motor data) are likely early candidates for J1939 over CAN FD. Manufacturers of off-highway equipment and trucks are starting to include at least some CAN FD capability in vehicles launched in the mid-2020s, especially in North America and Europe where the latest standards are adopted.

Notably, heavy-vehicle OEMs view CAN FD as an evolutionary upgrade that avoids the need for a wholesale architecture change. A Daimler Trucks study found that in current truck harnesses with very long CAN cable runs, classic CAN baud rates are effectively limited to ~667 kbps, but switching to CAN FD could allow up to 2 Mbps on the same wiring, significantly boosting throughput without re-wiring the truck. This kind of analysis supports OEM decisions to implement CAN FD in new models: it offers a path to higher bandwidth using existing physical infrastructure, which is very appealing in the cost-sensitive, long-life heavy-duty vehicle sector.

Adoption Levels: By 2023–2024, only a few truck OEMs have publicly announced CAN FD in production, but industry experts anticipate a steady increase in adoption through the later 2020s. Over the next five years, more manufacturers will introduce multi-bus architectures that pair one or more classical CAN J1939 networks with at least one CAN FD-based J1939 network. For instance, a truck might retain a 250 kbps CAN bus for critical powertrain control (ensuring backward compatibility with older tools or engines) and add a 500 kbps/2 Mbps CAN FD bus for high-resolution telemetry, advanced sensor data, or faster ECU programming. By the late 2020s, it is expected that most new heavy-duty vehicles in North America and Europe will incorporate CAN FD in some portion of their J1939 communications – although classical CAN will likely remain in parallel use for many years.

Fleet Owner Acceptance: Fleet operators and maintenance teams generally do not oppose the move to CAN FD, as it is largely transparent in day-to-day operations. In fact, fleets stand to gain benefits from CAN FD such as shorter service times for software updates and richer data for vehicle health monitoring. One tangible advantage is faster ECU reprogramming and diagnostics – programming times can potentially be cut to a third or even fifth of current durations when using CAN FD, reducing vehicle downtime. Recognizing these benefits and the inevitability of new technology, the fleet maintenance community has been preparing for CAN FD. For example, the American Trucking Associations’ Technology & Maintenance Council (TMC) held training sessions in 2022 to introduce technicians to “the next generation of CAN called CAN FD” and demonstrate troubleshooting of CAN FD networks. Heavy-duty scan tool vendors (NEXIQ, Bosch, Snap-On, etc.) have also updated their products so fleets can service CAN FD-equipped trucks with minimal disruption. Overall, fleet acceptance is high as long as new J1939-FD vehicles come with compatible adapters and the transition is managed to maintain backwards compatibility with older fleet units.

OEM and Supplier Insights: CAN FD vs. Automotive Ethernet

A key strategic question has been whether to invest in CAN FD or pivot directly to Automotive Ethernet for heavy-duty vehicle networking. In practice, OEMs and Tier-1 suppliers indicate that both technologies have roles to play, and their plans reflect a hybrid approach:

Rationale for CAN FD: OEMs view CAN FD as a way to boost bandwidth without massive changes to existing J1939-based systems. It preserves the familiar CAN software stack and diagnostic procedures, which is valuable given the industry’s 20+ years of J1939 experience. As one SAE J1939 committee member noted, using CAN FD is a “perfect solution” to increase bus capacity without large changes to existing critical ECUs like engine or brake controllers. This sentiment is echoed across OEMs who see CAN FD as a low-risk evolution: migrating to CAN FD is significantly less effort than moving to an entirely new network standard. Importantly, the extra data payload in CAN FD also enables new functions – for example, adding cybersecurity and functional safety metadata into J1939 messages. Industry experts point out that with only 8 bytes, classical CAN could not fit cryptographic signatures or authentication counters, but the 64-byte frames in CAN FD allow heavy-duty vehicles to adopt automotive security protocols (e.g. SecOC) and safety mechanisms. In fact, the push for in-vehicle cybersecurity is one factor that “has in large part driven” the transition to CAN FD in heavy trucks, because it provides the space and bandwidth to implement those safeguards.
Role of Automotive Ethernet: At the same time, truck OEMs are introducing automotive Ethernet (100Base-T1 and 1000Base-T1) for certain high-data applications. Ethernet is seen as the future-proof solution for very high bandwidth needs – for example, high-resolution camera feeds, radar and LiDAR data, or over-the-air update data pipes. The new “next-generation” tractor-trailer interface standard being developed in North America explicitly plans for multiple Ethernet networks as well as CAN and CAN FD in the tractor-trailer connector of the future. This means a truck and its trailer could communicate via one or more Ethernet links for big data transfers (e.g. streaming video from trailer cameras), while still using CAN/CAN FD for real-time control messages. Major suppliers also design products with both interfaces (as shown by the Aceinna IMU example) to cover all OEM preferences. In interviews, Tier-1 leaders have noted that most new vehicles will ultimately have an Ethernet backbone, but they also clarify that CAN/CAN FD will remain in use alongside Ethernet for many domains. In essence, Ethernet is starting to handle the “data heavy” domains (autonomy, connectivity, infotainment), whereas CAN FD can efficiently serve traditional control domains with moderate bandwidth requirements.
OEM Planning and Perspectives: OEM statements suggest a pragmatic adoption curve. European truck makers (e.g. Daimler, Volvo) and North American OEMs (e.g. PACCAR, Navistar) have been evaluating CAN FD in test fleets and new architectures. Daimler Trucks, for one, worked with Bosch on proof-of-concept upgrades of their CAN networks – reports indicate they successfully trialed replacing a classical CAN bus with a CAN FD network in a truck, validating the performance improvement and informing their next-gen E/E architecture designs (which also include Ethernet). Meanwhile, off-highway machinery OEMs (Caterpillar, John Deere, etc.) have been active on the SAE committees – Caterpillar has even led development of J1939 functional safety and security protocols tailored for CAN FD (J1939-77 and J1939-91C), underscoring that they anticipate CAN FD to be used in their future products. Broadly, OEMs indicate plans to use CAN FD for the foreseeable future in domains like engine/powertrain, chassis, and body control, even as they add Ethernet for things like driver assistance systems. They emphasize that CAN FD extends the life of the reliable CAN/J1939 paradigm: “in many domains CAN will still remain the dominating bus system” even as Ethernet backbones emerge. This coexistence strategy is expected to last through at least one or two truck generations (5–10+ years).

In summary, OEMs and Tier-1 suppliers see CAN FD and automotive Ethernet as complementary. CAN FD is an immediate upgrade path to relieve bus load and enable new features on J1939 networks with minimal upheaval, while Ethernet is being adopted in parallel for high-bandwidth data and future scalability. The consensus is that heavy vehicles will not abandon CAN/J1939 anytime soon – instead, they will implement CAN FD for a boost now, and weave in Ethernet where it makes sense, creating a multi-network vehicle architecture.

Market Trends and Outlook: Does CAN FD Make Sense in an Ethernet Era?

The market trend in commercial vehicles points to a hybrid network topology in new designs, and this shapes the outlook for CAN FD:

Short to Mid Term (2020s): CAN FD clearly makes sense as an interim step for heavy-duty vehicles. It addresses pressing needs (bandwidth, security) and leverages the huge installed base of CAN technology. Analysts predict a period where vehicles routinely have multiple J1939 networks: some using classical CAN and at least one using CAN FD. This allows OEMs to incrementally upgrade different subsystems. For example, a 2025 model truck might use a CAN FD bus at 2 Mbps for an advanced engine and aftertreatment system (handling the higher data from new emissions sensors and faster ECU flash), while retaining a 250 kbps CAN bus for legacy trailer ABS communications or simple body controls. By 2025–2030, CAN FD is expected to become commonplace in heavy vehicles’ control networks. During this time, automotive Ethernet will also penetrate the heavy vehicle market but likely in specific roles – e.g. serving as a backbone between domain controllers, or linking high-speed sensors to a central computer. Many new truck platforms will thus combine J1939/CAN FD for core vehicle control with Ethernet for high-data and off-board connectivity. This trend is bolstered by the automotive industry’s push for Ethernet (driving down cost and proving its reliability), but heavy-duty manufacturers will continue to rely on CAN FD where it is adequate, due to its simplicity and deterministic broadcast nature for critical control data.
Long Term (2030s and beyond): There is some debate on the longevity of CAN FD in the face of ever-faster networking options. One school of thought is that CAN FD will eventually plateau – if vehicle data demands continue to grow exponentially (with autonomous driving, V2X communication, etc.), even 2 Mbps CAN FD may become insufficient. The CAN community has a next step (CAN XL up to ~10 Mbps), but heavy vehicle standards bodies have not yet committed to it. It’s possible that by the time CAN FD networks start hitting capacity limits, automotive Ethernet (with 100 Mbps to multi-gigabit speeds) will be cheap and robust enough to handle most in-vehicle communication. In fact, the marine industry (which shares J1939 roots via NMEA 2000) intentionally skipped CAN FD – they went straight to an Ethernet-based standard (OneNet) for their next-gen network, reasoning that a jump from 0.25 Mbps CAN to 100+ Mbps Ethernet was more worthwhile than a modest step to 2 Mbps CAN FD. Some experts in the heavy-duty space have mused that CAN FD might similarly be a “short-lived compromise” before Ethernet-based J1939 variants take over. This viewpoint cites the rapid emergence of applications like telematics, autonomous operation, and over-the-air data streaming, which eventually demand bandwidth and flexibility that only Ethernet/IP networks can provide.
Counterpoint – Lasting Value of CAN FD: On the other hand, many industry voices believe CAN FD (and potentially CAN XL after it) will coexist with Ethernet for the long haul in heavy vehicles. The reasoning is that not all in-vehicle communication needs ultra-high throughput; there are plenty of periodic sensor readings, actuator commands, and status messages that CAN handles elegantly. CAN FD’s added bandwidth (up to ~4-6x over classic CAN) is likely sufficient for a large portion of these use cases even moving forward. Additionally, CAN networks have intrinsic advantages in simplicity, real-time multicast, and extremely low cost per node – advantages that Ethernet-based solutions (which require switches, IP addressing, etc.) may never fully match for simple control functions. The likely scenario in commercial trucks is a mix of network types: Ethernet will carry heavy data streams (e.g. high-def video from a truck’s camera system or a platooning coordinator), while CAN FD networks continue to reliably broadcast things like engine torque messages, brake commands, and diagnostics. In this multi-network environment, the J1939 standard will also evolve to ensure interoperability and security across the channels (for example, standards for secure transport over CAN FD are in development).

In summary, market trends support the adoption of CAN FD in the near term as a prudent upgrade, even as the industry simultaneously embraces Ethernet for new functions. CAN FD is viewed as an extension of the CAN legacy that will work in tandem with Ethernet. Over time, if Ethernet proves able to handle virtually all vehicle communications affordably, the dependence on CAN FD could diminish – but that point appears well beyond the current planning horizon for truck manufacturers. For the next decade, the consensus is that CAN FD does make sense: it fills the gap between aging 500 kbps CAN and cutting-edge Ethernet, giving heavy-duty OEMs a flexible option to meet bandwidth needs without overshooting cost or complexity. CAN FD’s adoption is thus a bridging strategy that leverages the best of both worlds – preserving what works in today’s J1939 networks while opening the door to the data-intensive future.

Implementation Challenges for Component Suppliers

While the move to CAN FD brings clear benefits, it also poses several challenges for ECU and component vendors that must be managed:

Backward Compatibility: Perhaps the biggest challenge is that CAN FD is not backward-compatible with classical CAN on the same bus. A CAN FD frame will not be recognized by a legacy CAN 2.0 ECU, so one cannot simply mix old and new nodes on a single J1939 network. This forces a conscious decision for vendors: either upgrade all nodes on a bus to CAN FD at once (which in a truck could mean redesigning dozens of ECUs), or introduce separate parallel networks (one CAN FD, one classical) and partition the nodes. Neither approach is trivial. The parallel network approach maintains functionality of old nodes but adds cost and complexity (extra wiring, gateway bridging, etc.), and gatewaying between a CAN FD segment and a CAN 2.0 segment to exchange J1939 messages is complex due to timing and transport layer issues. On the other hand, a “big bang” full network upgrade requires every supplier’s device (engine controller, transmission, ABS, instrument cluster, etc.) to have CAN FD capability, which may not be feasible all at once. This lack of seamless interoperability means suppliers must coordinate closely with OEMs on rollout strategy. Wilfried Voss, an industry commentator, bluntly noted that CAN FD incompatibility “prevent[s] the new protocol from operating on the same network as Classical CAN” – a pain point that inevitably complicates adoption.
Hardware and Software Redesign: Supporting CAN FD typically requires updated microcontroller hardware and CAN transceivers in each ECU. Most semiconductor suppliers (NXP, Infineon, Microchip, etc.) now offer CAN FD controllers and transceivers, but for an ECU maker, integrating a new CAN FD chip may entail a redesign of the circuit board and extensive software retesting. The cost of redesign is non-trivial, especially for smaller Tier-2 suppliers of niche devices who must invest in new tooling and validation for a feature that only some customers may immediately use. Component vendors also need to ensure signal integrity at higher CAN FD speeds. Truck wiring harnesses are long and often unshielded; running at 2 Mbps data phase means tougher constraints on stub lengths and termination. Vendors have had to test their CAN FD physical layers to confirm that, for example, existing 9-pin connectors and long cable runs can handle the faster rise times. (Some studies showed that many existing CAN transceivers can work up to 2 Mbps on truck-length buses, but beyond that would require new designs.) In short, every CAN-connected product – from engine ECUs to trailer brake controllers – must be evaluated and likely updated for CAN FD, which is a significant engineering effort across the supply chain.
Cost and Economic Considerations: Upgrading to CAN FD can increase unit costs initially. New CAN FD controllers/transceivers might cost a bit more, and there is the engineering cost to redesign and re-certify products as mentioned. For vendors of devices that also serve the retrofit or aftermarket, there’s a need to support dual protocols – e.g. a telematics module might need to communicate via classic J1939 on older trucks and CAN FD on newer ones, adding complexity and cost in development (such devices often include two CAN interfaces to cover both, as we saw with the NEXIQ adapter and other examples). The timing of adoption is therefore critical for suppliers: they prefer to introduce CAN FD when volumes justify it. Many have waited until OEMs signaled firm production use (around 2023+) to avoid premature investment. Now that the major OEMs in Europe and North America are moving that way, suppliers are racing to offer “J1939-22 compliant” updates. There is also a training and tooling cost – test equipment, manufacturing end-of-line testers, and technician training all need updates for CAN FD. For smaller component makers, absorbing these costs to remain compatible can be challenging, especially if they must continue supporting classical CAN for years in parallel.
Integration with Other Technologies: Another subtle challenge is ensuring CAN FD fits into the broader vehicle network architecture smoothly. As vehicles gain Ethernet, LIN, and other buses, the software gateway strategies become more complex. Suppliers must implement protocol translators or adapt their J1939 stack to possibly work over CAN FD and Ethernet (some OEMs might even carry J1939 messages over Ethernet/IP in certain cases). Maintaining consistent J1939 functionality across different physical layers (CAN vs. CAN FD vs. Ethernet tunneling) could require additional development and testing by suppliers, who need to guarantee that their device’s J1939 messages have the same effect regardless of network medium. This is a new consideration that did not exist when all was one CAN bus.

Despite these challenges, component manufacturers are actively addressing them. Many have been involved in the SAE task forces, gaining head-start knowledge on J1939-22 requirements. As a result, by 2025 a growing number of J1939 component vendors (ECU makers, sensor suppliers, etc.) have product lines ready or in development for CAN FD. They are aided by the fact that core technology support is now in place – the availability of CAN FD silicon, testing tools, and software stacks is much improved compared to a few years ago. Additionally, lessons from passenger car CAN FD deployments (which began earlier) are filtering into the heavy-duty realm. The heavy vehicle industry’s deliberate, committee-driven approach has also produced guidelines to manage transition pain points (for example, recommended practices for a backward-compatible tractor-trailer connector that can carry both CAN and Ethernet signals). In summary, while upgrading to CAN FD poses non-negligible challenges in compatibility and cost, the industry is navigating these by phased implementation, parallel networking where needed, and upfront coordination between OEMs and suppliers. The end result will be a more capable J1939 network that sets the stage for future innovations while maintaining the reliability that the heavy-duty sector demands.

Conclusion

The integration of CAN FD into SAE J1939 is well underway in the medium and heavy-duty vehicle markets of North America and Europe. It represents a strategic balancing act: embracing a faster, higher-capacity CAN-based network to meet immediate needs (more data, better security) while gradually preparing for an Ethernet-centric future. We have seen tangible evidence of adoption – from CAN FD-capable engine gateways and telematics units to OEM commitments for next-gen truck architectures. Truck manufacturers and fleet owners alike recognize that CAN FD offers a valuable, incremental upgrade that extends the life and capability of the trusted J1939 ecosystem. At the same time, there is a clear understanding that it’s not an either/or choice with Ethernet: the two will co-exist, each handling different facets of the vehicle’s communication needs.

In the market today, acceptance of CAN FD J1939 is growing steadily. Early adopter OEMs are implementing it in high-end models and critical systems, and others will follow as standards mature and benefits are proven in operation. Fleet maintenance networks are gearing up with compatible tools and training, indicating confidence that this technology will take hold. The trends suggest CAN FD will thrive through the later 2020s, especially as a backbone for vehicle control networks, even as Ethernet makes inroads for data-intensive applications. Challenges in implementation – notably the lack of backward compatibility – are being addressed through thoughtful network design and collaborative rollout so that legacy support is maintained.

In conclusion, implementing CAN FD within the SAE J1939 framework does make sense for heavy-duty vehicles, given the industry’s evolutionary approach. It is a practical solution that aligns with the long development cycles and reliability requirements of trucks and buses. CAN FD is breathing new life into J1939 by quintupling its bandwidth and enabling new features, all without sacrificing the robustness that users expect. As one report quipped, it lets manufacturers “get more data on the same pipe” instead of adding many parallel CAN buses or jumping to a completely new standard. Looking ahead, CAN FD’s adoption will likely accelerate, but it will do so alongside a controlled infusion of Ethernet – a dual trend that together will future-proof commercial vehicle networks. By tackling the transitional challenges and leveraging both technologies, the truck and bus industry is ensuring that it can meet rising data demands while preserving backward compatibility and cost-effectiveness. In the end, the deployment of CAN FD in J1939 is a clear example of the heavy vehicle sector’s pragmatic innovation, bridging the old and the new to drive forward into an increasingly connected, data-driven era.

Sources: The information above is drawn from recent industry publications, standards committee updates, and product announcements, including Kvaser and Copperhill Tech analyses of J1939-CAN FD, a 2025 J1939 technology outlook by industry experts, OEM statements on network evolution, and examples of CAN FD implementations in commercial vehicle products.

References

https://www.sae.org/standards/content/j1939-22_202103/
https://www.csselectronics.com/products/canedge-2-can-logger-wifi
https://www.nexiq.com/Product/USB-Link-3
https://www.aceinna.com/inertial-systems/IMU330RA
https://www.iwavesystems.com/product/telematics-control-unit/
https://tmc.trucking.org/
https://vector.com/int/en/products/products-a-z/software/canalyzer/
https://www.peak-system.com/PCAN-Explorer-6.276.0.html
https://www.kvaser.com/about-can/can-fd/
https://copperhilltech.com/blog/can-fd-and-its-implementation-in-automotive-applications/
https://www.sae.org/works/committeeHome.do?comtID=TEVXC9
https://www.bosch-mobility.com/
https://www.sae.org/standardsdev/committee/j1939-77/
https://cvta.org/
https://www.nmea.org/content/nmea_standards/onemet.asp