Diagnostics and electrical
Fault codes read and traced where the unit sits — charging, air, aftertreatment and wiring.
- Codes traced
- On site
- Cause, not symptom
Diagnosed, not guessed
A fault code names a symptom, not a cause. Swapping the part the code points at is how a unit comes back down a week later with the same light on and a second invoice behind it.
Patriot brings the diagnostics to the yard. Codes are pulled and the system is tested before anyone orders a part, so the repair matches the fault that actually stopped the truck.
What gets traced
- Fault codes
- Read on site across engine, transmission, brake and body controllers, then tested rather than taken at face value.
- Charging and starting
- Batteries, alternators, starters, cables and grounds — measured under load, not swapped on suspicion.
- Aftertreatment faults
- DPF and EGR problems worked back to the cause, including the sensors and plumbing that trigger them.
- Air system faults
- Leaks, dryers, governors and valves found with the system pressurised rather than inferred from a gauge.
- Wiring and connectors
- Chafes, corrosion and bad grounds traced through the harness — the faults that read as intermittent until somebody finds them.
- Findings recorded
- What was tested, what it measured and what was concluded, logged to the unit so the next visit starts informed.
How a diagnosis runs
- 01
Describe the fault
What the unit is doing, when it does it, and what the dash is showing. Intermittent faults are worth describing in detail.
- 02
Read and test
Codes are pulled on site, then the circuit or system behind them is tested to confirm what the code is actually reporting.
- 03
Quote the repair
You get the cause and the fix, priced from standard repair times, before any part is ordered.
- 04
Repair and verify
The fix is made and the system re-tested, so the unit leaves verified rather than merely code-free.
Before you call
Can you diagnose an intermittent fault?
Often, yes — that is usually a wiring, connector or ground problem, and it is found by testing the circuit rather than by reading the code again. Describe when it happens and it helps.
Do you have the software for my make?
The mobile shops carry diagnostics for the makes Patriot services. Tell dispatch what you run and it will be confirmed before the visit.
What if the fault is something you cannot fix on site?
You get the diagnosis, in writing, along with what the repair needs. That is yours to act on whether or not Patriot does the work.
Will you just clear the code?
No. A cleared code with the cause still in place is a unit that comes back down, and that is the outcome the whole service is built to avoid.
Other services
Mobile Truck Repair
Diagnostics and repair on Class 6–8 units, in your yard. Brakes, air systems, electrical, aftertreatment and hydraulics — closed out on site.
ProgramPreventive Maintenance
Scheduled PMs on your intervals, tracked in the portal, quoted by SRT before a wrench turns.
ComplianceDOT Inspections
Annual federal inspections performed on site, so units never leave the lot to get stickered.
Put it on the schedule
Give dispatch the unit, the fault and the yard. We'll confirm the technician and the service window, then come to it.