From minor repairs to major engine issues, the first step is finding out what’s really wrong. Jonathan’s Fleet Service brings computer diagnostics to your truck to read fault codes, check live data and track down the cause — so you pay to fix the problem, not to guess at it.
What we diagnose
- Check-engine and warning lights
- Engine derates and power loss
- Aftertreatment, DPF and regen warnings
- Charging and starting problems
- Electrical faults
- Overheating and cooling issues
Forced regens
Modern diesel engines burn off the soot that collects in the diesel particulate filter (DPF) through a process called regeneration. When a truck can’t finish a regen on its own — short trips, idling, a stuck sensor — the filter loads up, warning lights come on and the engine may derate. A forced regen uses a diagnostic tool to command the regeneration while the truck is parked, often getting it back to full power without a trip to the shop.
Truck in derate? Call 210-765-2933. We can often diagnose and run a forced regen right where you’re parked.
Diagnosis first, then the repair
Clearing a code isn’t a fix. We look for the reason the code set, explain what we found, and then make the repair — with dependable workmanship and quality parts to keep your equipment running strong.
Questions
What is a forced regen?
A forced (parked) regen is a DPF regeneration started with a diagnostic tool while the truck sits still. It burns off built-up soot when the truck hasn’t been able to clean the filter on its own.
How do I know if my truck needs one?
Common signs are a DPF or regen warning light, a message asking for a regen, reduced power or a derate. Call and tell us what the dash shows.
Can you just clear the code?
We can, but a code usually comes back if the cause isn’t fixed. We find the reason first so the problem stays gone.