Confused between DRL and headlights being on...
04-21-2018, 06:49 PM
#1
Confused between DRL and headlights being on...
Just picked up a 2012 CTT. When the **** is on auto, it turns on the headlights and twilights. All the time. When it’s in the off position, I get the 4 LED lights in each headlight. Is this right? I would have thought leaving it on auto would turn on the 4 LED lights but not the headlight/taillight. What am I not understanding?
04-21-2018, 07:10 PM
#2
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It depends on a few things. Are you trying this in your garage? If so - chances are the light sensor on the dash isn't seeing enough light to determine if it's daylight, so it assumes night and turns the lights on for night use - full headlights and taillights. There is also an option on the Vehicle settings for how DLR works - I'd suggest the manual.
04-21-2018, 07:16 PM
#3
It’s outside in bright daylight where the headlights are on. I’ve turned the DRL off in the PCM and the headlights and twilights still stay on in full auto. But the LEDs turn off when the **** is switched to off. Just doesn’t seem normal.
04-21-2018, 08:42 PM
#7
Where is this? I don’t see that setting. I have a fade out timer and the only option related to DRL is on/off. Those are the only two options for exterior lighting in the PCM.
What at is the latest PCM version for a 2012? Where do I find out what version I have?
What at is the latest PCM version for a 2012? Where do I find out what version I have?
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04-21-2018, 10:55 PM
#8
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This is your second (or third?) new thread about lighting problems. Any chance you have a flood vehicle from Houston or east coast.?
04-21-2018, 11:13 PM
#9
It’s from New York...I had it inspected by my Indy once it arrived and he didn’t say anything about that. I feel he’s pretty good, he’s worked on a lot Exotics/RollsRoyces etc
04-22-2018, 12:32 PM
#11
Rennlist Member
Light switch in off position: 4 l.e.d.s will remain lit if you have DRL's toggled on in the PCM.
Light switch in Auto Position (Daytime): 4 l.e.d.s will remain on if you have DRL's toggled on in the PCM.
The headlights and taillights should not be on in the daytime with the switch in the Auto position.
It's that simple. You seem to have an issue.
04-22-2018, 02:16 PM
#13
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I'd have to go dig in the manual to see which light sensor they use for the lighting. There are several - the auto-dimming mirror has at least 1, perhaps 2 on the back of the mirror (used to control the mirrors), the HVAC has one in the center of the dash to measure the ambient light falling on the car. Not sure if the light system has it's own, or shares output from one of the others.
04-22-2018, 03:11 PM
#14
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Spent an hour in the service manual and on AllDataDIY - can't find any reference to a light sensor. There is the dash mounted solar sensor, and the rearview mirror forward light sensor. It appears there may actually be some sort of link between the rain sensor and the lighting system, but it's not clear what it is.
Does your rain-sensing wiper work OK? The rain-sensor is supposed to be replaced when the windshield is replaced, at a minimum the silicone seal that connects it to the inside of the windshield must be replaced, and many of the mobile windshield guys don't have a clue.
Does your rain-sensing wiper work OK? The rain-sensor is supposed to be replaced when the windshield is replaced, at a minimum the silicone seal that connects it to the inside of the windshield must be replaced, and many of the mobile windshield guys don't have a clue.