No heat - Toyota/Lexus - Techstream Solution

[Tom777]

2 years I have studied my issue with not getting any heat on passenger side on a UK car. I am very proud to have solved the issue myself. Look what I created (fire: movie: Cast Away).

I had to put the Techstream software on it to perform: INITIALIZE SERVOMOTOR. This is a utility/function provided by the Toyota Techstream software - used as per MANUAL when Battery has been replaced or disconnected or servomotors (blend doors for USA) have been replaced. Imagine, some advice on the web is to disconnect Battery when you have this issue with not getting hot air on one side or uneven temperature between the two sides. The exact reason why you might get this issue in the first place. It’s bloody fixed-  It needed actual recalibration, not bleed air, not heater flush, not new actuators/servomotors, not new sensors, not advise “have you tried to adjust dual temperature settings”, lol… and this and that…. 

It was a calibration functionality for AirCon in Techstream that fixed it. I hope this helps anyone in the future who is about to give up life and their Lexus. Never give up on a Lexus!

NOTE. Not all toyotas and Lexus have this Techstream option: “Initialize Servomotor” option, but my IS250 2007 did. Do your own research regarding models. I spend £150 before I found the solution. Don’t spend £700 on a heater core replacement with your local mechanic before this step as per Lexus manual has been implemented. Your local mechanic might know nothing of it but your Lexus Dealer might do - hopefully. Initialize Servomotor

[Tom777]

Heater core replacement is probably more than £700 - most likely £1000 just in man hours. £1200 in total with new heater core. SOFTWARE RULES THE WORLD. 

[NemesisUK]

It's a relatively common problem and the same solution in Mercedes models. The air distribution flaps go out of sync/calibration and just need resetting via MB Star diagnosis software. Always the first thing to try.