"As someone already stated...the REST (RESidual heaT) button was changed to the MAX button on later model BMWs. And the residual heat feature was retained. All of the same requirements are needed for this feature to function even when you have the MAX button.
See the information below from your owners manual on how your IHKA system works depending on if you have the MAX button or the REST button"
Newer BMWs With Max Button:
Older BMWs With Rest Button:
