Mobile Diesel Diagnostics — We Bring the Scan Tool to You
Check-engine lights, derates, sensor faults and intermittent gremlins — diagnosed at your yard before they strand you.
Modern trucks rarely fail without warning — they tell you first. A check-engine light, an intermittent code, a regen that won't complete, a 5-mph derate counting down. Ronin Mechanical brings dealer-level diagnostic capability to your truck anywhere south of Duncan, reads what the ECM actually says, and translates it into a plain-English decision: fix now, fix scheduled, or safe to run.
We scan and diagnose all major North American makes and engines — Cummins, Detroit, PACCAR MX, Volvo, Mack MP and Navistar power — covering engine, aftertreatment, transmission, ABS and body controllers. Because the diagnosis happens at your truck, you're not paying to tow a driveable vehicle or losing a day parking it at a dealership.
What we handle on-site
- Full ECM fault scans — engine, transmission, ABS, aftertreatment
- Check-engine and stop-engine light diagnosis
- Derate and limp-mode troubleshooting with the clock ticking
- DPF/DEF & emissions system fault diagnosis and forced regens where appropriate
- Electrical and sensor fault tracing
- Pre-trip and pre-purchase health checks
- Written findings you can keep for your records
Diagnosis you can act on
A code is a symptom, not a verdict. We test what the code points at before recommending parts, and we show you the data. If it's a $40 sensor, you'll hear that; if it's a failing injector, you'll see why. Repairs happen on the spot when parts are available — picked up at dealer cost with the receipt in your invoice — or get scheduled by text at your convenience.
For fleets, regular scan-and-report visits catch pattern failures early. Pair diagnostics with a preventive maintenance program and most roadside emergencies simply stop happening.
Related services
Book a mechanic — by text
Fastest: the wizard builds a clean dispatch text with your issue, truck and location, and copies you on it.
Start the 60-second bookingOr text us directly:
Prefer voice? Call the same number. 24/7 emergency roadside + scheduled maintenance by appointment.
- $130/hour — around the clock
- Zero markup on parts (receipts included)
- No call-out fee, no zone fees
- Estimate our travel time
Mobile Diagnostics & ECM Scans — FAQs
My truck is in derate — how long do I have?
Depends on the fault. Some emissions derates step down over hours, others hit 5 mph on the next key cycle. Don't gamble on it: text 250-974-7899 with the message on your dash and your location, and we'll tell you honestly whether to stop now or whether you can limp to a safer spot for the repair.
Can you clear codes and get me rolling?
We can clear codes where it's appropriate, but clearing without fixing usually brings the light back — sometimes with a harder derate. Our job is to find and fix the cause at your truck; when a temporary reset is a legitimate bridge (say, to get you to your yard), we'll do it and tell you exactly what still needs attention.
Which engines and makes can you scan?
Kenworth, Peterbilt, Freightliner, Western Star, Volvo, Mack, International, Hino and Isuzu, with coverage for Cummins, Detroit, PACCAR MX, Volvo/Mack and Navistar engines, plus transmission, ABS and aftertreatment systems. If you run something unusual, text the details and we'll confirm coverage before booking.
Is a mobile diagnostic cheaper than the dealer?
Usually, and it's almost always faster. You pay $130/hour for time on site instead of a tow both ways plus a multi-day dealer queue. If the fix does need a dealership (warranty or proprietary programming), you'll know before you spend the tow — and you'll arrive with the fault documented.
Truck down? Text us your location.
A real dispatcher replies fast — you and dispatch both get the booking by text. 24/7 emergency roadside + scheduled maintenance by appointment.