How to fix DRL light problem in a Honda Civic.
Recently my 2003 Honda Civic has developed minor electrical issue.
Occasionally, upon starting engine, DRL (Daytime Running Lights) warning light may come ON with annoying buzzing sound. It may stay ON for few minutes and then goes OFF itself.
When it's happened first time, I checked front lamps and DRL lights were flickering.
To prevent things from getting worse and, maybe, save a couple bucks, I've started looking for solutions among technical web community. Internet search has revealed that this is a quite common failure and it's caused by DRL module itself. In most cases described problem has arisen because of degraded soldering joints on a module PCB.
Well, we've got tip so let's check it out...
DRL relay module is a gray box with connector on a bottom, labeled MITSUBA RZ-0126. It's located under the dash to the left of the steering column. DRL module is accessible through removable cover under steering wheel. It's fastened to metal bracket with one 10mm bolt.
Box can be easily open with flat screwdriver. One sided module PCB contains two 12V relays and other electronic components.
Let's see what we have here...
Aha, all culprits are right there!!! Cracked soldering joints of relay pins are clearly visible.
Long lasting annoying problem has been fixed in a 10 seconds by resoldering all 7 pins of every relay.
DRL module from auto parts supplier would cost at least 50$ ;-)
Of course my case was easy one and DRL warning light on your car may lit because of other possible reasons but anyway, DRL relay module should first thing to check.