If you receive a code 18 warning on the information and message screen on your Opel Corsa instrument panel, it means that there is a fault with the left dipped beam in the vehicle. The meaning of this error code is the same in Opel’s Astra, Mokka and other models.
Possible reasons are the bulb may be blown, the bulb holder may be broken, the sensor may not be working properly, the cable may be loose, etc.
So these are the first things to check when you get a code 18 error. In some cases, although the code 18 error appears on the screen, it is seen that there is no problem with the left dipped beam light on. This situation has the following explanation:
While the on-board computer analyzes the data from the sensors, it compares the data according to the required value ranges. Let’s say there is a short interruption in the data or there is a deviation from the normal values, then it gives the error code 18.
Anything that is electrically connected has always had issues like no contact or cable slack. Let’s say there is a slight lack of contact between the bulb and the socket, or due to the road conditions, the loosened cables create a lack of contact from time to time, in this case, the lamp remains on even in one-tenth of a second cuts, but the brain gives a code 18 error because the sensor detects this contact.
In other words, if you are getting code 18 error in your Opel Corsa vehicle, even if the left dipped beam lights up without any problems, you should still show the vehicle to a mechanic.
No misunderstanding
Some people investigating the code 18 error in the Opel Corsa vehicle may encounter engine fault codes on the internet. However, the code 18 error that appears on the screen has nothing to do with the engine fault codes. You can access the engine fault codes only if you have the vehicle computer read the fault diagnosis device. If the check engine light is on in the vehicle.
However, the Opel Corsa code 18 error appears directly on the message screen. Let’s say that the code 18 error appears on the screen, but at the same time, the engine fault lamp on the instrument panel is on.
In such a case, it may come to mind that the code 18 error occurs due to another problem in the vehicle, and it is necessary to read the engine fault codes with a fault diagnosis device to find out.
And I want to make a final warning. If you are going to replace the left dipped beam bulb, pay attention to the original voltage range, otherwise you may experience problems such as heating or not giving enough light.
