On-Site Diagnostics
On-site diagnostics bring scan tools and test equipment to the vehicle so the problem is understood before decisions about towing or repair are made.
- AvailabilityCalls and messages 24/7
- WhereRoadside, yard or jobsite
- CategoryRoadside & Emergency Assistance
- On-site repairWhere feasible and safe
About on-site diagnostics.
On-site diagnostics bring scan tools and test equipment to the vehicle so the problem is understood before decisions about towing or repair are made.
A mobile mechanic can look at the unit where it stands, whether that is the roadside, a yard or a jobsite. That can avoid a tow and shorten downtime when the fault is suited to on-site work.
Part of Roadside & Emergency Assistance.
When you might need it.
Any of these is a good reason to call and describe what the unit is doing.
Warning lights or derates
Unexplained faults
Pre-purchase or pre-trip checks
Repeat breakdowns
What the service involves.
Code reading
System testing
Visual inspection
A clear explanation of findings
Causes and good habits.
These are possibilities, not a diagnosis. The only way to know is to test the unit.
Possible causes
- Fault codes and derates
- Intermittent problems
- Unknown noises, leaks or smells
Practical tips
- Write down the codes and symptoms
- Tell us what changed before the fault
What to expect.
Diagnosis may confirm that a shop repair is required.
On-site repair depends on the fault, parts, vehicle condition, safety and service feasibility.
(437) 601-8551Before you call
- Exact location, and direction of travel on a highway
- Truck or trailer type, make and year if known
- What happened and what warnings you see
- Whether the unit is somewhere safe
- A number we can call back
From the first call to the fix.
Call or message
Tell us where the unit is.
Describe the fault
Symptoms, lights, noises, leaks.
Agree the plan
Feasibility and dispatch, discussed honestly.
Diagnose and repair
On site where it is possible and safe.
Services that often go together.
Engine Diagnostics & Troubleshooting
When a heavy-duty engine derates, stalls, loses power or throws fault codes, finding the actual cause matters more than clearing a light.
Check Engine Light Diagnostics
A warning light is a symptom, not a diagnosis.
Electrical Troubleshooting
Electrical faults can be maddening.
Mobile Truck Repair
Mobile truck repair brings a mechanic and tools to the truck, whether it's at the roadside, in a yard or at a jobsite, to cut downtime and avoid unnecessary towing..
Frequently asked questions.
Is diagnosis separate from repair?
It is the first step. Repair follows where feasible.
How do I request this service?
Call (437) 601-8551 or message us on WhatsApp with your location and the issue. For non-urgent work, use the contact form.
Can every repair be done on site?
No. It depends on the fault, parts, vehicle condition, safety and feasibility.
Stranded on the Road? Let's Talk.
Tell us where your truck or trailer is located and what happened. Contact Fellows to discuss mobile repair options and next steps.
(437) 601-8551Have ready: exact location, truck or trailer type, what happened or what warnings you see, whether the unit is somewhere safe, and a callback number. Timing, dispatch and on-site repair depend on location, availability, the fault, parts and safety.