Venting the low-temperature cooling system
Immobilization period-long fill of coolant!
Do not reuse used coolant.
When replacing and removing components which rely on the corrosion protection effect of the coolant, it is essential to change the coolant. The cooling system must therefore be emptied and refilled.
In the case of other removal work involving the draining of part quantities of coolant, the coolant level must be topped up with new coolant.
Filling without the vacuum filling equipment (watering can filling) is not permitted .
If this is not observed, there is a risk of component damage or engine damage. The filling specification must be observed.
It is essential to visually check the vacuum filling equipment before use to check that it is functioning correctly and clean.
It is not permissible to operate the vehicle if the filling procedure has not been fully completed. Otherwise there may be functional limitations (degradation) or overheating.
A bleeding procedure is required after a part has been exchanged in the cooling system and/or after refilling the cooling system.
Before starting the automatic cooling system bleeding procedure, make sure that all coolant circuits are filled . If the cooling system bleeding procedure is started while one of the coolant circuits is empty, there is a risk of damage to the electric coolant pump when running it dry.
Make sure that terminal 15 is not disconnected for the bleeding procedure . Switch on low-beam headlights and hazard warning lights. If the low-beam headlights and hazard warning lights are not switched on, the ignition (terminal 15) will switch off automatically after a certain period of time and interrupt the bleeding procedure.
The driving dynamics control must not be set to the ECO PRO switch position.
- Adjust the coolant level in the low-temperature coolant expansion tank (1) to the lower edge (2) of the coolant filler neck of the low-temperature coolant expansion tank (1).
- Close the sealing cap on the coolant expansion tank of the low-temperature coolant circuit.
- Ensure that the hood is open .
- Connect battery charger.
- Activate testing-analysis-diagnosis (PAD) by quickly pressing the START-STOP button three times.
- Activate the low beams and the hazard-warning lights at the same time .
If the low beams and the hazard-warning lights are not turned on, the ignition (terminal 15 ) turns off automatically after a while and interrupts the bleeding procedure.
- Ensure that Driving Dynamics Control is not in the "ECO PRO" switch position.
- Set the heating to the maximum temperature and the blower to the lowest level.
- Press the accelerator pedal up to the stop for at least 10 s and do not press the brake pedal while doing this.
- Do not start the engine.
The cooling system bleeding procedure starts.
The electric coolant pump is activated in the low-temperature coolant circuit according to a cooling system bleeding procedure for 11 min.
The cooling system bleeding procedure is ended after 11 min.
The electric coolant pump is not activated any longer.
- Observe the display in the instrument cluster (KOMBI).
If the service function is canceled, the cooling system bleeding procedure must be repeated.
- Let the coolant temperature cool down to < 50°C .
- Loosen sealing cap (1).
After the cooling system bleeding procedure, the cooling system is topped up via the maximum mark. Overfilling the cooling system serves to balance the remaining air in the cooling system. The normal fill level of the coolant is reached during driving.
- Adjust the fill level in the coolant expansion tank of the low-temperature coolant circuit to 50 ml above the maximum mark .
- Close sealing cap (1).