From MY 2007, the additional heating system is available for the F06 and G06 Combi and F36 Tour models and is designed to provide extra heating capacity for the rear interior space of the vehicle when the engine is running. The additional heating system is available with or without the auxiliary heating system, described in “Functional Description: Auxiliary Heating System” .
The additional heating system comprises a heating unit, control panel, bypass solenoid valve and associated coolant pipes and hoses.
Additional Heating Unit
| 1. | Intake ducting |
|---|---|
| 2. | Blower unit |
| 3. | Heater matrix |
| 4. | Outlet ducting |
The blower unit is located on the underside of the chassis by means of three long studs and secured by means of nuts.
The intake ducting (1) is attached to a duct that connects with the air intake grille located in the front door step on the left side. Heated air is discharged, via the outlet ducting (4), into the rear of the vehicle via a vent unit on the floor at the front of the rear passenger compartment.
The additional heating system is activated manually by means of a four position rotary control switch located on a control panel on the headlining. If the vehicle is equipped with rear air conditioning, the rear air conditioning control switch is also installed in this panel.
Only the blower fan speed can be controlled using the rotary switch. The air temperature is controlled using the temperature control on the instrument panel and is dependant on engine coolant temperature.
System Schematic and Logic
A – Diesel Models
B – Petrol Models
| 1. | Engine coolant pump | 4. | Coolant pump, electrically driven | |
|---|---|---|---|---|
| 2. | Auxiliary heater (if installed) | 5. | Additional heater matrix | |
| 3. | Bypass solenoid valve | 6. | Main heater matrix |
When the rotary control switch is in the “0” position, the bypass solenoid valve (3), coolant pump (4) and blower unit are not activated. In this condition, coolant is circulated by means of the engine coolant pump (1) through the main heater matrix (6) only.
When the control switch is rotated to any position other than “0”, then power is supplied to activate the bypass solenoid valve (3), the coolant pump (4) and the blower unit at the selected fan speed. Under these conditions, the bypass solenoid valve allows coolant to flow through both outlet connections, thus enabling both heater matrixes (5, 6) to be operational.