If you are investigating only part of the rear window defrosts, save every stored and pending code before clearing anything. Electrical testing should follow the vehicle’s diagram and defroster specifications. 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. Inspect grid lines and connector tabs visually; avoid scraping or probing the glass. 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.