True Diesel is Houston's trusted independent semi-truck repair facility specializing in advanced diagnostics, electrical troubleshooting, and module programming for Class 8 commercial vehicles.
From precision diagnostics and electrical systems to full mechanical repair, True Diesel delivers expert-level service built for the demands of Class 8 trucks and commercial fleets.
Full-system fault analysis using OEM-level scan tools. We read and interpret J1939 data streams, SPN/FMI codes, and live parameters to pinpoint issues across engine, aftertreatment, ABS, and body controller systems.
Wiring harness repair, circuit tracing, relay and sensor diagnostics, ground fault resolution, and complete electrical system troubleshooting for all major OEM platforms including Freightliner, Peterbilt, Kenworth, Volvo, and International.
ECM, TCM, ACM, and body controller programming and reflashing. Parameter configuration, speed calibrations, VIN writing, DPF/SCR/DEF system resets, and aftertreatment module setup for new and replacement units.
In-frame overhauls, injector replacement, turbo diagnostics, overhead adjustments, and complete engine repair for Detroit, Cummins, PACCAR, Volvo, Navistar, and Hino platforms.
Manual and automated transmission service including clutch replacement, shift calibration, DT12, I-Shift, Eaton Fuller, and Allison diagnostics. Complete rebuild and replacement support.
Powertrain swaps, glider kit builds, engine-to-transmission conversions, and custom wiring integration. We handle the electrical and programming complexity most shops avoid.
Off-vehicle module testing, bench flashing, VIN cloning, and parameter verification. Ideal for diagnosing suspect modules before installation or prepping replacement units.
Mobile diagnostic and repair response for breakdowns in the greater Houston area. Equipped with scan tools, electrical testing equipment, and common repair parts to get you moving.
Transparent, competitive shop rates for all repair and diagnostic services. We quote upfront and communicate clearly — no hidden charges, no surprises. Contact us for current rate information.
True Diesel is an independent semi-truck repair facility based in Houston, Texas, purpose-built around the services that matter most: advanced diagnostics, electrical troubleshooting, and module programming.
Where other shops outsource complex electrical problems or send trucks to the dealer, we handle it in-house. Our ASE Certified technicians work with OEM-level tooling across every major platform — Freightliner, Peterbilt, Kenworth, International, Volvo, Mack, and more.
From fault code analysis and wiring harness repair to ECM programming and full engine work, we deliver the technical depth that fleet owners and owner-operators depend on to keep their trucks running.
Every service we offer is built around precision, transparency, and commercial-grade capability.
OEM-level scan tools and J1939 protocol expertise for precise fault identification across all systems.
Full-spectrum electrical troubleshooting — from wiring harness repair to complex circuit tracing and sensor diagnostics.
ECM, TCM, and ACM programming handled in-house — no dealer dependency, no delays.
Engine overhauls, transmission rebuilds, clutch work, and general mechanical repair under one roof.
Based in Houston with roadside service capability. We understand downtime costs money and respond accordingly.
Transparent quotes, clear communication, and no unnecessary upsells. We earn trust through results.
Fleet managers and owner-operators across Houston count on True Diesel for the jobs that require precision and expertise.
"Had an intermittent electrical fault on our Cascadia that two other shops couldn't find. True Diesel traced it to a chafed harness behind the dash in under two hours. These guys actually understand electrical systems."
"Needed an ECM reflash and aftertreatment reset on my 389 Pete. They had the tools and the software to do it same day. No dealer run-around. Professional shop with real technical capability. Highly recommend."
"We run 14 trucks and True Diesel handles all our diagnostic and electrical work. They communicate well, quote fair, and get the job done right the first time. Best independent truck shop in Houston for anything electrical."
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