1985 Autocar: we work on any truck
If it runs diesel and needs help, we'll show up. Age is not a barrier: classic, vintage, or modern.
Mobile Volvo Truck Repair
Volvo Truck Repair in Charleston, SC. We Come to You.
Field diagnostics and repair for Volvo VNL, VNR, VHD, VNX and VAH trucks wherever they are parked. We work D11, D13 and D13TC engines, I-Shift automated transmissions and the one-box aftertreatment system, and we confirm the failed part with testing before you pay for anything to be ordered.
- D11, D13 and D13 Turbo Compound derate, EGR and aftertreatment faults
- I-Shift shifting complaints, air supply and electrical diagnostics
- Charleston, North Charleston, Summerville, Goose Creek, Mount Pleasant
What We Handle On-Site
Volvo problems we diagnose and repair
One-box aftertreatment and DEF
On D11 and D13 trucks, Volvo packs the DPF, the SCR catalyst and the DEF injector into a single one-box housing, with EGR working upstream. We check DEF quality and dosing, look for a crusted injector tip, and compare NOx readings before and after the catalyst.
EGR flow codes and power loss
A D13 that loses boost, stumbles or derates with EGR flow codes is often reacting to a bad reading, not a bad valve. The EGR differential pressure sensor and its connector take a beating from vibration, so we check the sensor, its hoses and the wiring before anything gets replaced. We test the circuit and the signal first.
D13TC and D13 VGT specifics
The D13 Turbo Compound uses an extra turbine that turns exhaust energy into torque at the crankshaft. The newer D13 VGT in the latest VNR runs on a 24-volt electrical system. Each changes what we test, so we confirm which one you have first.
I-Shift, air and electrical
The I-Shift is an automated manual that shifts on air. Slow or missed shifts, a truck that will not pick a gear, or a clutch fault often trace back to low air supply, a tired air dryer, or a wiring and connector issue. We read the transmission codes and test the air system at the truck.
Volvos in the Lowcountry
VNL sleepers, VNR day cabs and VHD dump trucks
Volvo Trucks North America builds five main families. The VNL is the long-haul tractor, the VNR covers regional and pickup-and-delivery work, the VHD is the vocational truck behind dump, mixer and roll-off bodies, the VNX is the heavy-haul tractor for loads up to 225,000 pounds, and the VAH is the car hauler in 300, 400 and 600 cab versions.
The all-new VNL arrived in 2024 in six cabs, from the VNL 300 day cab to the 74-inch VNL 860 sleeper. The D13 Turbo Compound is standard across the VNL line. The VHD comes standard with the D11 and offers the D13, while the VNX runs the D16. Many Volvos shift through an I-Shift automated manual, and vocational trucks can carry the I-Shift with crawler gears, which adds one or two ultra-low ratios so a loaded truck can creep as slowly as 0.6 mph.
We are independent, not a Volvo dealer. We bring our scan equipment and test gear to the truck and work the problem from fault codes, live data and hands-on testing. Mack is part of the same Volvo Group, so many diagnostic habits carry over.
Why operators call us
- Mobile service where the truck is sitting
- Testing before parts replacement
- Clear written findings and next steps
- Commercial diesel and fleet-focused support
- 24/7 Charleston-area availability
How We Work
What to text us about your Volvo
1. Model and engine
Tell us VNL, VNR, VHD, VNX or VAH, the engine (D11, D13, D13TC or D16), and the year or the last eight of the VIN.
2. A photo of the dash
Snap the warning lights and the fault codes on the driver display. Note whether the truck is speed-limited, stuck in a gear, or will not shift out of neutral.
3. What led up to it
Did it start after a fuel stop, a DEF fill, a long idle at the terminal or a pressure wash? That timeline often points us at the right system.
4. Where it is parked
Yard address, dock door, jobsite gate or mile marker, plus anything that limits access, like a gated lot.
5. We test at the truck
DEF dosing and quality, NOx sensor readings, DPF pressure and temperatures, EGR signals, boost, air pressure build-up and leak-down, voltage drop on power and ground circuits.
6. Repair and a written report
We fix the sensor, connector, doser, leak or wiring behind the fault, and send a plain-language record of what was tested, what failed and what to keep an eye on.
Need a Volvo truck mechanic in the Charleston area?
Call or text Lowcountry Diagnostics any hour, and we will bring the diagnostics to your Volvo.
Common Volvo truck repair questions
Do you work on the D13 Turbo Compound engine?
Yes. The D13TC uses a turbo compound unit to send recovered exhaust energy back to the crankshaft. We diagnose D13TC trucks on-site for EGR, aftertreatment, boost and sensor faults, the same as a standard D13 or D11.
My Volvo is derated with DEF or SCR codes. Can you fix it where it sits?
In many cases, yes. We test DEF quality, the DEF injector, NOx sensors and the related wiring in the one-box aftertreatment system, find what set the derate, and repair it so the truck does not drop back into reduced power after the codes clear.
Can you diagnose I-Shift shifting problems?
Yes. We read I-Shift fault codes and check the things it depends on, including air supply, air dryer condition, and the wiring and connectors to the transmission. That covers standard I-Shift units and I-Shift with crawler gears on vocational trucks.
Do you clean Volvo DPFs?
Yes, we offer DPF cleaning. First we check DPF pressure readings, exhaust temperatures and regen history to confirm the filter is really the problem and not a sensor, an EGR fault or an injector that keeps loading it with soot.
Are you a Volvo dealer?
No. Lowcountry Diagnostics is an independent mobile diesel service based in Goose Creek, led by founder and lead technician Joseph Cufaude with 13 years in the diesel trade. We come to your truck across the Charleston area 24/7. Call or text (843) 310-0995.
Request Volvo Truck Repair
Tell us where the Volvo is and what it is doing. If the truck is down or derated, a call or text reaches us fastest.
Truck down or derated? Call or text (843) 310-0995 now.
Recent Repair Photos
A look at the repairs we make
Real field photos from Lowcountry Diagnostics, from engine diagnostics and electrical to hydraulic, HVAC, and heavy-duty truck service, handled on-site across the Charleston area.
Reviews
What Charleston truck owners and fleets say
“Great team, personal and professional. These men were responsive and had great diagnostic equipment paired with experience…”
“These guys really know their stuff. Couldn't recommend em more.”