I have been intrigued by auto headlights ever since I first had my 2008 Civic. I have always thought it would be a nice feature to have. I am again intrigued now that the Ex-l in new 9thgen Civic has that capability. Recently when I was looking at the wiring diagrams for our Civic's audio and I-mid systems I had also looked at the headlight wiring diagrams. I discovered that there are three parts in the auto headlight system. There is a sensor, a control unit, and the turn signal stalk. Initially I didn't think it could be possible because the Control Unit is wired into the B-Can communication system. Today on the 8thGenCivic site I learned of updates on project to switch to an auto climate control system. In the update the guy's wiring diagram had him tapping the hvac controls into the b-can system. This got me thinking that it might be possible to add the auto headlight control module to our system. It is unknown if when the control module is introduced into the b-can system that it would be recognized, function, or present the sensitivity controls in the I-Mid menus. Although it seems like that it might be a possibility.
The dashboard wiring harnesses on the LX and EX are different than the EX-L that has the auto headlights. Regardless, the wiring for this system doesn't look too complicated. There is no splitting or rewiring of the existing wiring. There are six wires going to the control unit and they are all tapped into the existing wires in the car. I already have two of the three parts for this system. I am only missing the control unit. I purchased the sensor when I purchased the fog light kit. They were purchased prior to me having access to the diagrams and having knowledge of the control unit. Its very tempting to purchase the last part in this project to see if it indeed could work. However I don't have any immediate plans throw almost $200 at a project that has the potential to not work.
The dashboard wiring harnesses on the LX and EX are different than the EX-L that has the auto headlights. Regardless, the wiring for this system doesn't look too complicated. There is no splitting or rewiring of the existing wiring. There are six wires going to the control unit and they are all tapped into the existing wires in the car. I already have two of the three parts for this system. I am only missing the control unit. I purchased the sensor when I purchased the fog light kit. They were purchased prior to me having access to the diagrams and having knowledge of the control unit. Its very tempting to purchase the last part in this project to see if it indeed could work. However I don't have any immediate plans throw almost $200 at a project that has the potential to not work.
| Part # | Description | MSRP | Discount |
| 39850-TR0-A02 | CONTROL UNIT | $222.13 | $173.26 |
| 39860-TR0-A01 | SENSOR ASSY., AUTO LIGHT | $73.13 | $57.04 |
| Turn Signal Stalks | |||
| With Fog lights | |||
| 35255-TR0-X11 | SWITCH ASSY., LIGHTING & TURN | $27.03 | $21.09 |
| Without fog lights | |||
| 35255-TR0-K11 | SWITCH ASSY., LIGHTING & TURN | $23.62 | $18.42 |
