Reverse sonar comes on with headlights, won't shut off, Bad sensor or switch?
 

Ok, about a month ago, a car pulled up behind me and my reverse sonar alarm started sounding. I turned the car off, and back on, and the alarm came right back on. As I pulled away from the car behind me, it went back off. At the next red light, it came back on as the car behind me got closer. I got home and I noticed that the 4 LED chips on the top of my reverse light were on...the LED chips on the sides of the light were NOT on. If I turn the headlights off, the sonar alarm acts normally/only comes on in reverse. I turn on the headlights, and all is well...after 2-5 minutes, the alarm starts sounding again. The top 4 LED chips were coming on with the headlights...headlights off, chips off.

Figuring it was somehow related to the taillights, I pulled both taillights and plugged in the incandescent bulbs (except the reverse bulb), which eliminated the taillights as having anything to do with the problem. I did notice, however, that the reverse LED chips are ALL completely out now, until I shift into reverse. With the incandescent bulbs in, the problem still exists...doing exactly the same thing. Any ideas before I call the stealership?

2 days later, and everything was working fine again. This afternoon, after my car sitting outside in the rain all day, the rear sonar is doing the exact same thing. This is what I get at the taillights (with the headlights on):
http://i170.photobucket.com/albums/u...p/DSC04890.jpg

The four LED's facing the rear (in the reverse bulb) come on...as does the sonar...even with the car in drive or park. The only way to shut off the sonar alarm is to turn off the sonar (using the button beside the steering wheel), or turn off the headlights. If I turn off the sonar with the button, the rear LED's stay lit. I don't believe it's a problem with the switch. Is it possible that one of the sensors in the rear bumper is bad? If so...any idea how I can check them? It's been raining here all day, so I have to figure that something got wet.
I got into it with the jackass service manager at the dealership on my last visit, so I REALLY don't want to have to go back there.

I wanna say it could be backfeeding from somewhere. A bad led maybe? but more likely, a bad sensor.

I would find a reputable, knowledgeable auto electronic diagnostic guy (maybe an audio place, but it has to be a good one)

If you lived in RI I could point you to the guy who would find it (guaranteed) and barely charge you anything, but thus is life. Is the car still under warranty?

The car is still under warranty. I have the EZKonceptz tails, and I modded my interior to all blue, so I'm sure I'm going to get a hassle at the dealership. The service manager there is a total jackass.

how many sensors are there? can you unplug them one by one?

I believe there are 5 across the rear bumper. I'm going to play with it a little tomorrow. It was suggested that the NIRD-01 could be causing the problem, so I'm going to attack that angle next.

OK, I ran a sensor diagnstic just now, and the system is NOT showing any codes. CRAAAAAAP! I was REALLY hoping it was a bad sensor. I can't be so lucky!
Metra responded back via e-mail. The lead tech wants me to uninstall the NIRD...if the problem persists, he wants me to re-install the factory radio.

BTW, there are 4 sensors across the rear bumper.

OK, I just spent 1/2 hour disconnecting the NIRD-01 unit. I also disconnected the HVAC info screen, and the driver info screen. The problem is still there. I still have the top 4 LED chips lit and the alarm sounding as soon as I turn the headlights/parking lights on. I totally disconnected the NIRD...the white plug, and both black plugs. Apparently the NIRD isn't the problem. Any other ideas?

have you tried to unplug each sensor one by one yet? or see if its even possible?

No, I ran the sensor diagnostic from the FSM and it is NOT showing any codes. I talked to Metra, and they said call IPCW. I called IPCW and they are saying that the LED reverse lights are causing the problem. I'm going to call VLED's tomorrow and see if I can find anything out from them. If I have time tomorrow, I'm going to pull the tails AGAIN and remove the LED reverse bulbs and see if the problem goes away.

yeah if its one of the reverse LEDs, it probably was backfeeding (water could have gotten in there, burnt out led, etc)

I assumed you tried this already - when you had the housings out weren't they disconnected?

I pulled the LED housings and unplugged everything. I plugged the incandescent bulbs back into the plugs...but I don't remember if I swapped the reverse bulbs or not. I'm going to have to pull it back apart.