This morning, while driving my kids to school (in 6 degrees F weather), my interior / overhead / dome lights would not turn off. I opened and closed every door several times, as well as the hatch and hatch glass with no change. The only way to get them to turn off was to activate the dome light disable button on the dash. Even with this button enabled, the dome light switch (twisting the dimmer) still turns the dome light on and off as expected. At no point did I get a warning for the doors on DIC. It's as if the BCM was sensing a door open, lighting the interior lights but not indicating an open door on the DIC (hence the disable button and dimmer switch functioning as intended). I don't know if this is related to the cold - I know we have users here in colder climes. This is the first time I've seen this issue. I have no interior lighting mods at all. All bulbs are in working order.
Interior Lights stuck on
- Thread starter TequilaWarrior
- Start date
Mooseman
Moderator
It's not the auto dimming that's maybe keeping the lights on? What does it do with other doors? If you wait a good while, they don't turn off at all? I think they do turn off ultimately after 10 minutes for battery preservation.
The OEM 2002 Bravada Owner's Manual might have some extra info on the Cabin Lights Set Up around 2-43:
I drove my kids to school - total trip time over 20 minutes - and the only way I could get the lights to go out was to use the dome override button on the dash. All lights are on full brightness and remained on even after opening/closing all doors + hatch&glass with the car running.
Right now, sitting in my very cold garage, the all interior lights come on when I open the door and remain on after I close the door. When I lock the doors via the keyfob the headlights go out after a short period and the interior lights remain on. Several minutes have passed and the interior lights are still on. If I press the dome disable button, they go out immediately and remain off when doors are opened, but come on when the dimmer is turned to extreme (normal behavior).
Mooseman
Moderator
What about the other doors? I'd still be suspicious of the door switch. Mine does the opposite, not turning on the lights.
I've opened closed all the doors multiple times today with the same results. The only way I can get my lights to stay off is with the dome disable button engaged.
Is the same mechanism used to sense an open door used to turn on the interior lights?
Shouldn't whatever is causing my lights to come on also cause the DIC to tell me a door is open? (it is not indicating anything is open)
If I understand this system correctly, our interior lights are controlled by the BCM. The BCM turns on the interior lights based on several inputs, MOST of which are Serial DATA, either from the LCM, DDM, or PDM. 3 exceptions are the interior light switch that's part of the headlight switch and the 2 rear doors. The 2 rear door latch assemblies apparently have ground switches to command the interior lights on. It is not apparent to me whether these would also cause the BCM to detect a "door open" condition and display the message on the DIC. When the weather warms up, I will pop off the rear door panels and investigate whether one of these switches are at fault.
Does anyone know if the RR DR SIG and LR DR SIG inputs on the BCM are how the BCM knows the doors are open or if they are only to light the interior lights?
Does anyone know if the RR DR SIG and LR DR SIG inputs on the BCM are how the BCM knows the doors are open or if they are only to light the interior lights?
I am tempted to say it could be a failed headlamp switch. Or circuit 1495 has somehow shorted to ground? Sounds like what I would expect if the courtesy lamps switch failed in a closed state, meaning the BCM would be getting a constant "courtesy lamps on" signal. And when the courtesy lamps defeat switch was activated it may override the constant "ON" signal??
I think both conditions could be checked by disconnecting the harness at the headlamp switch. This is not too hard to do, gaining access through the left end of the dashboard at the access panel there. With the harness disconnected and the switch out of the dash you could test circuit 1495 for a short to ground and test the courtesy lamp switch as well for proper operation.
2¢
I think both conditions could be checked by disconnecting the harness at the headlamp switch. This is not too hard to do, gaining access through the left end of the dashboard at the access panel there. With the harness disconnected and the switch out of the dash you could test circuit 1495 for a short to ground and test the courtesy lamp switch as well for proper operation.
2¢
This sounds plausible were it not for the fact that the courtesy lamp switch still functions as designed. If I engage the dome disable button, the courtesy lamp switch still turns them off and on.
Mooseman
Moderator
What about the tailgate? If that switch or the glass switch is failed, the light would stay on however would get a tailgate open warning. My 02 had the glass switch fail randomly and would turn on the lights.
can you state / check if every door gives a "open port / door? message on the DIC? Each one should.
Blckshdw
Moderator
It's still ridiculously cold here, so I did a quick check of the doors while out shopping. All doors / hatch give a DIC warning, except passenger front door. Coincidentally, the passenger front window and seat heater no longer work either. It seems I need to check for a bad ground at that door (and maybe some fuses).
Blckshdw
Moderator
You can try swapping the DDM into the passenger door, if the functions return, then you have a bad passenger door module on your hands.
No need. I pulled the fuse for the PDM and reinstalled it. Windows, locks, seat heater now work as normal. However, my interior lights are still not working correctly.You can try swapping the DDM into the passenger door, if the functions return, then you have a bad passenger door module on your hands.
Does anyone know if the interior lights are triggered by the same mechanism that triggers the "door open" DIC notification?
Each door has only ONE switch that signals the module it is connected to. Front doors switches are wired to their respective door modules, left or right. Rear door switches are wired to the BCM. Hatch and hatch glass switches are wired to the LiftGate Module..
None of these switches carry power to light up anything. These switches are all low voltage input signals for the module they are connected to.
The courtesy lights are turned on or turned off by the BCM alone. Nothing else can do it because these courtesy lights are only wired to the BCM.
Even the switches in the headlight switch carry no lighting power. They are also low voltage signal inputs to/from the BCM.
Since each door only has a single switch (excepting the hatch) for open/closed it stands to reason that any "door open" message must be initiated by these switches via the module(s) they are connected to.
This is the explanation I needed....
Other than the door open signals, hatch & glass signals, and "interior light on" signal from the headlight switch, what would cause the BCM to light the interior lights?
Blckshdw
Moderator
Only other scenario that comes to mind, is hitting the unlock button on the key fob, when the daylight sensor on the dash doesn't have enough light, so it thinks it's night time and lights up the interior for you.
I've never waited to see if the lights turn back off if I didn't open one of the doors or liftgate though...
OK... but you didn't indicate whether that side now is detected with "open door" on dic.
Good catch. I just went to the grocery store and had my son help me test the doors. All doors set off the appropriate "door open" DIC message. Oddly, now my interior lights work as they're supposed to. I wonder if the PDM had a glitch and if pulling the fuse reset the PDM and it's now behaving as designed.... strange.
I rest my case.... too much tequila... 
I am suspecting poor connector / conductivity which might have been addressed with the disconnect / connect.
I am suspecting poor connector / conductivity which might have been addressed with the disconnect / connect.