My adventure with broken CIM unit in astra Hno horn but steering controls all workingCIM removed and replaced and programmedHorn working!!My Instagramhttps:/ Everything works except the horn, steering wheel roller etc. everything works. There is no difference whether with or without traffic lights, etc., as in other cases. In the test on the computer, the horn works, there are no errors in CIM. CIM replaced with a 100% functional one, programmed and exactly the same, everything works except the horn dear sir I have an Opel astra 1.7 ctdi and the following items do not work, 1- horn 2- wiper screen washing 3- Fuel level indicator Please help me with how I can repair them and solve the problems. thank you Two screws take the top part of the steering cowling off. Turn the steering wheel 90 degrees and you will see a small black cover. Take this off then remove the screw. Same at the other side. Get a torch and check down at the bottom on the left hand side as you look at it, that's roughly where the CIM clip is installed. Horn not working when lights switched on? 2006 Astra was quoted over 500 pounds for new cis unit. after a lot of digging found that dimming dashboard lights to minimum solves the problem well done mWih732.