If you are investigating temperature rising mainly in slow traffic, save every stored and pending code before clearing anything. Compare coolant-temperature data with the dashboard gauge and fan command if available. Record the engine temperature and load alongside the reading; the same value can mean different things in different conditions.
A basic reader may not access every module. Check for fan operation only from a safe distance and inspect for obvious coolant loss when cold. Use the exact vehicle’s service information to interpret the result.
Quick educational note
For information, not a diagnosis or repair instruction. Vehicle-specific checks are still required. Consult the manufacturer's guidance and a qualified technician.
How to use this information
This article explains general principles and does not establish what is wrong with your vehicle. Read the content limitations.