CT4 Adaptive Headlight System Malfunction Alert

As someone with moderate experience working on cars, I dealt with a very similar headlight malfunction on my 2020 CT5. The symptoms were nearly identical, inconsistent beam height and dashboard warnings related to the adaptive headlights system. After diagnostic testing, the workshop identified a faulty servomotor in the headlight assembly that controls the range control functionality. The electrical connectors were all intact, but the control module was receiving incorrect positioning data from the defective motor. The complete repair included: Replacement of the headlight servomotor, Recalibration of the adaptive headlights system, Testing of all headlight positions and scenarios Total cost was 1040€ including parts and labor. The repair took about 4 hours since they needed to carefully remove the entire headlight assembly to access the servomotor. To help troubleshoot your specific case, could you share: Are both headlights showing irregular behavior or just one side? Did the issue start suddenly or develop gradually? Have you noticed any other electrical issues with the vehicle? Does the problem occur more frequently in certain conditions? This information would help determine if your issue matches what I experienced or if there might be other factors involved.

Last service was completed at 35000 KM, and currently at 37633 KM. The lighting system issues actually got worse after trying a reset of the control module. Both headlights are now affected, showing irregular light intensity and incorrect positioning. The error codes point to a communication problem within the adaptive headlights system. My mechanic initially suggested checking the electrical connectors, but given what you described about the servomotor, I will have them focus on that component first. The symptoms started gradually over the past month, with no other electrical problems noted. Just booked an appointment for next week, hoping for a straightforward fix like yours rather than needing the entire headlight assembly replaced.

Thanks for the additional details on your CT4. Those mileage numbers and gradually worsening symptoms match almost exactly what I experienced with my CT5. The communication errors you mentioned following the control module reset strongly suggest this is indeed a servomotor issue. When my headlight system started failing, attempting a reset actually caused similar behavior, the beam adjustment became even more erratic and both lights were affected. One thing to note, while the servomotor replacement fixed my issue completely, make sure your workshop does a full diagnostic scan before starting work. The headlight malfunction could be masking other electrical system problems that developed after the initial failure. Since both headlights are now showing issues, have them check the wiring harness between the control module and both servomotors. In my case, there was some minor insulation damage that needed attention during the repair. The gradual onset without other electrical problems is actually a good sign, suggests the core headlight system components are likely fine. Would be interested to hear what they find during your appointment.

Thanks everyone for the detailed feedback on my CT4 headlight problem. Really appreciate hearing about that specific servomotor repair experience, it matches my symptoms exactly, especially how the lighting system issues got worse after the reset attempt. Going into my service appointment next week feeling much better informed. Will make sure to have them check both the servomotors and the wiring harness connecting to the control module. The fact that my issue also developed gradually without other electrical problems makes me hopeful its a similarly straightforward fix. Will update after the repair to let others know if it was indeed the same root cause. The adaptive headlights system is clearly complex, so having real repair examples like this helps tremendously when trying to diagnose light intensity and beam adjustment problems. Thanks again for taking the time to share your repair experience. It gives me a much clearer picture of what to expect when I bring it in.