BMS Fleet Diagnostics AI is an on-premises assistant for fleet operators and auto repair shops. It answers technician and fleet questions from vehicle specs, recalls and service data, with service manuals and repair history next, without sending shop or customer data to the cloud.
Diagnosing modern vehicles means digging through thousands of pages of manuals, bulletins, and past repair notes. That knowledge is scattered, and much of it lives only in senior technicians' heads.
Technicians spend significant time searching manuals and forums before they can start a repair.
Fixes for recurring issues are rarely captured in a searchable way, so the same problems get solved twice.
Fleets and shops are cautious about sending vehicle, customer, and repair data to third-party cloud AI services.
A retrieval-augmented, agent-based assistant built on locally hosted language models and accelerated by NVIDIA GPUs.
Everything runs on-premises. Models are served locally on NVIDIA hardware (currently an RTX 5090 workstation, with NVIDIA Grace Blackwell desktop hardware planned), so proprietary shop and fleet data never leaves the customer's network.
A technician describes symptoms or enters a diagnostic code.
The assistant retrieves vehicle specs, recalls and safety data, and cites the source of each answer. Service manuals are being added next.
Planned: completed repairs feed back into the knowledge base for the next similar case.
Real output from the development system, October 2026. The index holds 2,558 vehicles: 2,550 from the public EPA fuel-economy dataset (model years 2024–2025) enriched with NHTSA crash ratings and recalls, plus 8 hand-curated vehicles. Automotive service documentation is being added next.
Vehicles are chunked, embedded on the GPU and written to a two-tier index (vehicle summaries for routing, detailed chunks for answers) in checkpointed batches of 50 that are safe to re-run.
At fleet scale, text search matched the number in the question to numbers in model names. Typed attributes now let threshold and superlative questions run as SQL, while other questions stay on hybrid text search.
// Before: hybrid text search, top results mercedes-benz-s-class-2025-s500-4matic-... // "500" in the trim name lexus-ls-2025-500-rwd-3-4l-6-cylinder-... // same 0 of 3 expected vehicles returned // After: routed to structured search SELECT ... FROM vehicle_attributes WHERE horsepower > 500 ORDER BY horsepower DESC 3 of 3 expected vehicles returned: BMW M3 Competition, Chevrolet Corvette Z06, Rivian R1T
The model server and GPU-accelerated embedding and reranking services run on a local RTX 5090. Nearly all 32 GB of VRAM is held by resident model weights and KV cache. The serving processes run in containers, so they don't appear by name in the Windows process list.
PS> nvidia-smi +-----------------------------------------------------------------------------------------+ | NVIDIA-SMI 610.88 KMD Version: 610.88 CUDA UMD Version: 13.3 | +-----------------------------------------+------------------------+----------------------+ | GPU Name Driver-Model | Bus-Id Disp.A | Volatile Uncorr. ECC | | Fan Temp Perf Pwr:Usage/Cap | Memory-Usage | GPU-Util Compute M. | |=========================================+========================+======================| | 0 NVIDIA GeForce RTX 5090 WDDM | 00000000:41:00.0 On | N/A | | 0% 31C P5 45W / 600W | 31977MiB / 32607MiB | 0% Default | +-----------------------------------------+------------------------+----------------------+
Retrieval is scored against a 29-query golden set across eight categories and four difficulty levels. For attribute questions with many correct answers (“electric vehicles”), every vehicle that meets the criteria counts as relevant, with the relevant sets generated from the data.
| Stage | Passed | Recall | Precision |
|---|---|---|---|
| 8 curated vehicles | 28 / 29 | 98.9% | 53% |
| 2,558 vehicles, original labels | 15 / 29 | 51.7% | 10% |
| Open-world relevance labels | 20 / 29 | 67.6% | 26% |
| Structured search for numeric questions | 26 / 29 | 86.6% | 43% |
| Variant collapsing (one result per model) | 26 / 29 | 86.3% | 44% |
| Category (structured search) | Passed | Recall | Precision | |
|---|---|---|---|---|
| Features | 2 / 2 | 100% | 58% | |
| Safety | 3 / 3 | 100% | 39% | |
| Rankings | 4 / 4 | 100% | 15% | |
| Performance | 3 / 3 | 100% | 13% | |
| Fleet filter | 6 / 6 | 92% | 92% | |
| Maintenance | 3 / 3 | 83% | 42% | |
| Ownership cost | 3 / 4 | 75% | 31% | |
| Cross-chunk | 2 / 4 | 52% | 29% |
"good family car with low running costs" and "best car for someone who loves track days but needs daily practicality")
whose answers aren’t in spec data; query rewriting into structured constraints is the next step. One
is a data gap: only one vehicle has 5-year ownership-cost data.
Currently in active development.
Staff-level backend engineer with a background in large-scale distributed systems, working in Java and Python. Now focused on AI infrastructure: retrieval-augmented generation, multi-agent orchestration, and efficient local LLM inference.
BMS Fleet Diagnostics AI applies that experience to a practical problem: giving repair shops and fleet operators reliable AI assistance without giving up control of their data.
Interested in a pilot, a partnership, or just learning more? Reach out directly.
madhu@madhu-cloud.com