If the performance of the air-conditioning system is inadequate when outside temperatures are high, a faulty evaporator temperature sensor (see illustration example) may be the cause. Incorrectly measured values can cause the evaporator to freeze and block the air flow.

Headlamp cleaning systems improve visibility in the dark and prevent dazzling of oncoming traffic through stray light. On this page, find out about the structure of headlamp cleaning systems and how they work. You can also find useful tips here on using these safety systems along with information on troubleshooting in the event of malfunction.

With the above-mentioned vehicles, rattling, rather non-specific noises may occur when the engine is cold and the outside temperature is low. The noise disappears when operating temperature returns to normal. The dual-mass flywheel could be a possible cause of the problem.

To change the cabin filter/pollen filter on the vehicles mentioned above, proceed as follows:

• Switch off the ignition
• Move the passenger seat backwards
• Remove the trim in the passenger footwell

When starting the vehicle, the ignition switch gets stuck in the start position. As a result of this malfunction, the starter pinion does not disengage and this can lead to damage (starter, sprocket, etc.).

The activated charcoal canister protects the environment against unburnt fuel vapours. This page explains how the system works, what could cause a fault, and how malfunctions affect the running of the engine. You will also find valuable practical tips for troubleshooting in connection with the activated charcoal canister.

If the vehicles mentioned above experience starting difficulties, various causes may be responsible. Often the engine will not start until the starter is operated for more than 10 seconds. Sometimes several starts are necessary for the engine to start.

On the above-mentioned vehicle with an AFS headlamp system, the failure control lamp may all of a sudden come on. AFS (adaptive front lighting system) is a lighting system that uses movable lenses to adapt to the road conditions, the weather and to the speed situation.

On the vehicle mentioned above, it is possible that the ABS/ESP control lamp suddenly lights up. Often the error code C1606 (ECU/software error) is then stored in the control unit. A possible cause is "a software weakness" in the control unit of the front camera.

If headlamps or other vehicle lamps are fogged up on the inside, car drivers usually consider this to be a defect. However, in some cases this is a physical phenomenon. This page explains how this can come about. You will also find out what to do if water collects in the headlamp or other vehicle lamps. There is also a step-by-step guide for replacing faulty lamps, which provides a number of practical tips.

With the above-mentioned vehicle, various failures/malfunctions (cruise control, gear selector) may occur in conjunction with the multifunction steering wheel. The error message "cruise control failed" may then appear in the instrument cluster.

Upon identifying a steady coolant loss in the above-mentioned vehicles, check all coolant hose connections and the radiators for leaks. We recommend pressurising the cooling system with a suitable tool according to the manufacturer's specifications.