Diagnostics
3 article(s) on «Diagnostics». Most serious issues first.
High-voltage isolation fault: where it comes from and how the leak is found
Tesla's HV system runs at 350–800 V, and onboard monitoring watches the isolation constantly. Where current leaks to the body come from (moisture, road salt, aging, accidents), what an isolation fault threatens (from power limiting to a full no-drive lockout), and how a shop localizes the leak with a megohmmeter. Prevention tips for the Belarusian climate.
Radiator health in Service Mode: where the percentage comes from and why it falls
Firmware from the 2026.20.* branch added a radiator health percentage to Service Mode. In the summer of 2026 it sagged across the fleet: 79% on a refreshed Model 3, 83%, 76%, and for one owner 100% turned into 65% in three weeks. The number comes back to 100 neither after cleaning the stack nor after fitting a new radiator. What sits behind it, and when it really is about dirt.
Tesla diagnostic software: Scan My Tesla, OBD adapter & what it shows (2026)
Scan My Tesla is the go-to Tesla diagnostic app over OBD: real battery SOH, cell imbalance, temperatures, charge power. Which adapter you need for Model 3/Y and S/X, what it costs, what to check when buying used, and the alternatives (Service Mode, TM-Spy, Aviloo).