Safety comes first. This general guide does not determine whether a specific vehicle is safe to operate. Follow vehicle, carrier, cargo, facility, and public-safety instructions.
Protect the load without guessing
Follow the carrier, shipper, receiver, and cargo-owner procedures. A repair technician diagnoses equipment; cargo disposition and product-safety decisions belong to the responsible cargo stakeholders. Minimize unnecessary door opening and document temperature readings and communications.
Record the controller information
- Reefer unit make and exact model
- Active and recent alarm codes
- Setpoint and operating mode
- Supply-air and return-air temperatures
- Current box or product temperature when available
- Fuel level and battery or voltage indication
Observe without creating a hazard
- Does the unit start, stop, or attempt to start?
- Are belts present and turning normally?
- Is there unusual noise, smoke, odor, fluid, frost, or visible damage?
- Are the doors fully closed and seals intact?
- Is airflow blocked by load placement or ice?
Give dispatch the trailer details
Include the trailer number, exact location, cargo sensitivity, shipper instructions, remaining fuel, available external power if applicable, and whether the tractor can reposition the trailer. Clear information helps determine the tools, parts, and urgency.
Avoid common mistakes
- Do not repeatedly reset alarms without recording them.
- Do not change the setpoint or operating mode unless authorized.
- Do not assume a unit that restarted has corrected the cause.
- Do not promise cargo condition based only on a displayed temperature.