Rear turn signal failure

[Atp816]

Hey all,

I was hoping to get some input on a problem I just noticed in my turn signals.

I was checking my trailer lights yesterday (using my hazard flashers) and noticed that neither of my rear turn signals are working. The fronts are fine, and the trailer lights are fine, but not the tails on the truck. I thought maybe they’re deactivated by the trailer plug somehow, but after disconnecting they still won’t work. There’s no error message or light on the cluster, and I have no idea how long I’ve been driving without them working.

I checked every fuse in both panels, tried running hazards, left, and right turns independently, and I even popped the driver’s tail light housing out to check the plug for a signal. No flashing signal in any of the wires.

Parking, brake, and reverse lights all work though.

The last thing I did was to test the signal with alfaobd, which successfully activated/illuminated both rear turn signals. Alfa also didn’t pull up any error codes.

I’m stumped and nervous that it’s an issue with my bcm. I scheduled an appointment with a dealer but that’s a couple weeks out.. in the meantime, does anyone have any input regarding what I could check next?

 

[kapinallinen2]

Disconnect negative battery cable for 30 minutes.
How many settings have you messed with using the alfa OBD?

 

[Atp816]

Thanks for the advice! I had tried disconnecting it for 15 and had no change, but i tried again after you recommended it. I ended up leaving it disconnected overnight, but still nothing..

What ended up working was just going through my settings in alfaobd. I just checked anything related to exterior lighting and re-ran their configurations with the same values. Maybe that just reset things somehow, or maybe it resolved on its own, I don’t really know.

The weird part was that the rear signals worked again, but I lost my one touch lane change feature, then later in the day (driving in the rain, unsure if it was related) the front signals failed, one after the other. And this time the truck gave an error message in the gauge cluster for each failure. But I ran through alfa again and now everything seems to be working.

Hopefully things keep working, but I’m going to keep my appointment for the time being.