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Dome light issues any suggestions

26K views 23 replies 8 participants last post by  tpcrouch 
#1 ·
The dome lights on my 11' 350 6.7 CC stopped working. They worked one evening, and the next day nothing. I checked the 2 fuses at the kick panel fuse block and they are both good. Running lights and keypad light up as they should. The lights can be turned on individually with their respective switches, but nothing will turn them all on globally. I understand that dome light control is provided by the BCM.

Am I missing anything that can disable the dome lights? If not I think that I am looking at a new BCM. Does anyone know where the BCM is located? Thanks.
 
#2 ·
IIRC the BCM is located behind the right kick panel. It's not a matter of just plugging in a new one, it will have to be programmed too and because of the way the electronics are integrated the truck won't start unless the BCM is programmed.
 
#4 ·
Interesting? Is the high mounted stoplamp white lights coming on, it suppose to come on with the interior lights also, same BCM output power by fuse F12. I’m not sure but I believe this circuit is control by a FET (transistor) that protects the BCM circuit from higher then normal current, the fuse is basically there for a short circuit. I’m guessing but in simple terms that FET shuts off the circuit to a point that the light won’t come on but you can read voltage with some digital meters.

That said, I wouldn’t want you to buy a new BCM without confirming it isn’t something else. One reason I wanted to know if the high mount came on with the door open? This wouldn’t confirm to me that the BCM output is not working, but that it is and your problem is with the interior circuit. I’m only looking at wiring diagrams so I’m guessing. I don’t know how many inputs to the BCM turn on the interior lights or which ones might prevent them from coming on?
 
#5 ·
The cargo lamps by the high brake light do not come on either. In fact I can not turn them on at all because the global on at the dimmer switch does nothing. When I open a door or use the remote the exterior lights all work as before except for the cargo lamps.
 
#6 ·
What I understand is the dimmer switch is not a rheostat like the older vehicles and it only for dimming the dash and radio lights. It should turn on the interior lights like states in the manual but does not dim them. This dimmer switch sends a digital signal to the steering column control module and makes it to the BCM on a HS Can BUS. Hope this makes sense. I guess you are back at testing the BCM output.

I sent you a PM
 
#7 ·
Thanks for those diagrams. I will check the wiring, but I doubt there is an issue there since the truck is so new. Looks like you are right and the BCM sends current through a FET. I wonder if the transistor failed.

You really need an oscilloscope, or proper IDS tool I guess to see if there is communication on the CAN bus. I suppose the fact that the dome lights are triggered by the door switches and the remote as well as the steering column control module rules out the column module.
 
#8 ·
You might try just disconnecting the batteries for a few minutes. That will reset the BCM and that has worked for me on several different vehicles.
 
#9 ·
I thought about doing that. I was thinking and the batteries have never been disconnected before. I will certainly give that a try. My wife and I both work the next 10 days in a row, so it will be a little while before I get a chance to try it. I will update when I get the chance.
 
#11 ·
True. I was recently troubleshooting the radiator fan in my Lincoln LS. As it turns out the PCM communicates with the fan over the CAN bus. That means that the radiator fan has a computer in it that can understand the PCM's requests (instead of controlling it with voltage). Literally, the radiator fan has a computer built in. I can't make this stuff up.
 
#13 ·
I still have not had a chance to disconnect the batteries because we have been working 12-14 hour days plus travel. I did get my factory repair manual in the mail and found something interesting. If only I had a code reader that could pull these codes. At the very least it looks like the BCM has a mode where it disables the interior lighting circuit to protect itself.

U1000:00 Solid State Driver Protection Activated -Driver Disabled: No Sub Type Information The module has temporarily disabled an output because an excessive current draw exists (such as a short to ground). The Body Control Module (BCM) cannot enable the output until the cause of the short is corrected. ADDRESS all other DTCs first. After the cause of the concern is corrected, CLEAR the DTCs. REPEAT the self-test.

Or this....

U3000:49 Control Module: Internal Electronic Failure The module has permanently disabled an output because an excessive current draw fault (such as a short to ground) has exceeded the limits that the BCM can withstand. The cause of the excessive current draw MUST be corrected before a new BCM is installed. ADDRESS all other DTCs first. After the cause of the concern is corrected, INSTALL a new BCM . REFER to Section 419-10 . TEST the system for normal operation.

I wonder if disconnecting the batteries will reset/clear the code if it exists or if a scan tool is required.
 
#16 ·
Hey, I just had this issue with my 2011 F250. After having my dealership throw 3 BCM's at my truck, one of which I paid for ($700 total install) they decided to call engineers and do some more trouble shooting, they found a shorted wire in a factory sealed junction box. I don't know if you're problem is exactly the same but it sure sounds like it. I tried to express them, at the beginning, that I believed it was a short to ground somewhere by the way it was acting. The short that they found was internally frying every BCM they threw at it. I really hope this helps, cause I know how frustrated I was after not having my truck for multiple trips to the shop for sometimes as long as 7 days.
 
#17 ·
Thanks for that info. I haven't had time to get it to the dealership yet. Taking it out of service takes planning, though not having dome lights and a black interior are quite annoying. Did you pay for BCM #1, and the rest were warranty off the first one? I am just wondering because my dealership does not have the best troubleshooting record with me....
 
#18 ·
Yeah, I understand, I work graveyards and it was extremely frustrating getting in and out of the truck without any lights on. I did pay for BCM #1, after about 2 weeks that one fried. I took it back in and thats when they kept it for a week troubleshooting it, and eventually frying two more BCM's before they got it fixed. After the cost of the first BCM, my service advisor told me that I wasn't responsible for any cost of the second round due to them not finding the original issue and correcting it.
 
#21 ·
I still haven't gotten the truck to the dealer yet. I will soon though. Black interior, tint, and no dome lights cause quite the annoyance. I will update the thread for sure once I know.
 
#22 ·
I had the same issue, and upon removing the lense to make sure the bulb wasn't burnt out I noticed the plug was not pressed all the way in. A quick push with a pick tool and it was clicked into place, and my dome like was operational again.
 
#23 ·
UPDATE!!!

I know that it has been a while since I posted this thread, but I finally have resolution. I got the truck into the shop and they were able to reset the BCM codes. My dome lights are now working. I tried leaving the battery disconnected for a long time without any results. The BCM needs to be reset with the proper scan tool. Thanks for all the stories and suggestions everybody.
 
#24 ·
I know this is an old thread but in case anyone else has this issue I'm adding my reply.

I had this identical issue. It came about after I replaced the stock 2012 interior bulbs with the LED versions (name brand, not amazon crap). I was able to fix the problem by clearing the codes from the BCM using an Anova OBD2 scanner. I bought the high end version that included the diesel codes. I have to redo it every so often but its half the cost of a new BCM and it works.
 
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