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We are 100% diesel specialists. We don't work on gas-powered vehicles — our entire operation, tooling, training, and expertise is built around heavy-duty diesel platforms. This focus is exactly what makes us better at what we do. You're not bringing your truck to a general shop that also happens to fix diesels — you're coming to a shop where diesel is the only thing we do.

We service all major heavy-duty diesel brands:

• Cummins
• Detroit Diesel
• Caterpillar
• Volvo
• Paccar
• Mack
• International / Navistar
• Freightliner
• Kenworth
• Peterbilt
• Isuzu
• Hino

If you're unsure whether we service your make and model, call us and we'll confirm before you make the trip.

You can schedule in three ways:

• Call us at (281) 727-9374 — Mon–Fri 8:30AM–6PM, Sat 8:30AM–2PM
• Book online using our appointment form on the homepage — available 24/7
• Walk in during business hours — we'll do our best to accommodate you

For fleet accounts, contact us to set up a dedicated maintenance schedule with priority booking.

Yes. We stand behind our work. Warranty terms vary by service type — parts and labor warranties are provided at the time of repair. If you ever have a concern after a repair, call us and we'll make it right. Our 99% satisfaction rate and 4.7-star Google rating reflect our commitment to getting it done correctly the first time.

Yes — new customers receive a free initial diagnostic scan. We connect to your truck's ECM and pull the full fault code history at no charge. We then walk you through exactly what we found before quoting any repair work. No pressure. No surprises. Just an honest read of what's going on with your truck.

Most ECM diagnostics are completed same-day, often within a few hours. The initial fault code scan itself takes less than an hour. More complex fault resolution — such as intermittent faults, reprogramming, or multi-system faults — may require additional time. We'll always give you an accurate time estimate before we begin.

The Engine Control Module (ECM) is the computer brain of your diesel engine. It controls fuel injection timing, turbo boost, emissions systems, throttle response, idle speed, and dozens of other critical parameters. When the ECM malfunctions, stores incorrect calibrations, or develops communication faults, your truck can lose power, fail emissions tests, or refuse to start.

At AllTech Diesel, we use factory-level diagnostic tools to read, reprogram, and recalibrate ECMs on all major diesel platforms — something most general shops simply can't do.

Yes. ECM reprogramming and flashing is one of our core specialties. We can update factory calibrations, restore original programming after corruption, and apply custom ECU tuning for improved performance. We have OEM-level tool access for Cummins, Detroit Diesel, Caterpillar, Volvo, and Paccar platforms, among others.

Yes — don't ignore it. A check engine light on a diesel truck can indicate anything from a minor sensor fault to an active emissions derate that will eventually reduce your truck to limp mode. The sooner we read the codes, the easier and cheaper the fix typically is. Bring it in for a free diagnostic scan and we'll tell you exactly what's happening and what it will take to fix it.

Our full service menu includes:

• ECM Diagnostics — fault code reading, analysis, and resolution
• ECU Tuning — custom calibration for performance and efficiency
• DPF Solutions — cleaning, repair, and compliance services
• EGR System Repair — valve cleaning, cooler repair, delete services
• Engine Repair — Cummins, Detroit Diesel, CAT, and more
• Preventive Maintenance — oil, filters, belts, fluids, inspections
• Fleet Maintenance Programs — scheduled service for multi-unit fleets

Yes. DPF (Diesel Particulate Filter) issues are one of the most common problems we see in Houston, where heavy-duty trucks operate in demanding conditions. We handle DPF cleaning, flow testing, replacement, and full emissions system diagnostics. If your truck is throwing a DPF-related fault or going into regeneration cycles excessively, bring it in — we'll diagnose the root cause, not just clear the code.

Yes. We offer custom ECU tuning and calibration for improved torque, fuel efficiency, and throttle response on supported platforms. All tuning work is done with OEM-grade tools and applied safely within manufacturer tolerances. Call us to discuss your specific truck, operating requirements, and tuning goals before scheduling.

Yes. We handle engine repairs ranging from minor component replacements to full overhauls on Cummins, Detroit Diesel, Caterpillar, and other major platforms. Every engine repair starts with a thorough diagnostic to confirm the root cause before any parts are ordered or installed — we won't guess on a job like this.

Yes. Preventive maintenance is the best way to avoid costly repairs down the road. Our PM services include oil and filter changes, coolant flushes, air filter replacement, belt and hose inspections, fuel system service, and complete multi-point inspections. We can set up a recurring schedule based on your mileage intervals or time-based requirements.

Our fleet program is built around keeping your trucks on the road and out of the shop. We assign a dedicated fleet coordinator to your account and build a custom service schedule based on your routes, mileage, and manufacturer intervals. You get:

• Priority scheduling — fleet trucks go to the front of the line
• Multi-unit pricing — discounted rates for multiple vehicles
• Preventive maintenance tracking — we track every service interval for you
• Emergency repair priority — breakdowns get immediate attention

Call us to discuss your fleet size and requirements.

No strict minimum. We work with operations of all sizes — from 2-truck owner-operators to large multi-vehicle fleets. The program structure and pricing is customized to your situation. Contact us to get a quote based on your specific fleet.

Yes. Fleet accounts can be set up with dedicated invoicing and flexible payment terms. Talk to us about your billing needs when you set up your fleet account — we work with trucking companies and logistics operators regularly and understand the requirements.

Fleet account customers get emergency repair priority. Call our shop directly and identify yourself as a fleet account customer — we'll slot you in immediately. For critical breakdowns, we'll get a technician on your truck as fast as possible. Downtime is money, and we treat it that way.

Repair costs depend entirely on the specific fault, parts required, and labor time. We always provide a written estimate before beginning any work, and you must approve it before we proceed. No surprises, no unauthorized charges.

For new customers, we start with a free diagnostic scan to identify the issue first — so you know exactly what needs to be fixed and what it will cost before committing to anything.

We stand behind our work. Warranty terms are provided in writing at the time of repair and vary based on the type of service and parts used. If you experience any issue related to a repair we completed, contact us immediately — we'll evaluate it and make it right. Our track record of 99% customer satisfaction reflects how seriously we take this commitment.

We accept cash, major credit cards, and debit cards. Fleet accounts can be set up with invoicing and net terms. For specific billing questions, call us before your appointment.

We are located at 4215 Guessena St., Houston, TX 77020 — in East Houston, TX. We serve owner-operators and fleet companies across the greater Houston area and Gulf Coast region.

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• Monday – Friday: 8:30 AM – 6:00 PM
• Saturday: 8:30 AM – 2:00 PM
• Sunday: Closed

You can book an appointment online at any time through our website, even outside business hours.

Our shop is based in East Houston but we serve customers from across the greater Houston metro area and Gulf Coast region, including Pasadena, Baytown, Galveston, Beaumont, Texas City, and surrounding areas. If you're hauling through Texas, AllTech Diesel is worth the stop — our customers regularly drive in from across the region for our ECM diagnostic work.