2004 Mercedes C-Class Owner's Manual - Page 171
2004 Mercedes C-Class Manual
Page 171 highlights
Controls in detail Automatic climate control* Residual heat and ventilation With the engine switched off, it is possible to continue to heat or ventilate the interior for up to 30 minutes. This feature makes use of the residual heat produced by the engine. Activating Turn the SmartKey in the starter switch to position 1 or 0, or remove it from the starter switch. Press button ° ( page 163). The indicator lamp on the button comes on. Deactivating Press button ° ( page 163). The indicator lamp on the button goes out. The residual heat is automatically turned off: when the ignition is switched on after about 30 minutes if the battery voltage drops i How long the system will provide heating depends on the coolant temperature and the temperature set by the operator. The blower will run at speed setting 1 regardless of the air distribution control setting. 171