Headlight Switch Acting Funny

[breeves002]

This is a weird tiny issue that has happened a handful of times only recently. This didn't happen for my first 4 months of ownership. It seems to have started to happen after my trip to the dealer for the PAAK update along with other updates but correlation isn't causation as there have been several OTA updates as well (though only to GWM and TCU).

What happens is I'll open the driver door and the chime will go off like you have the headlight switch in a position other than "off" or "auto". I ALWAYS leave my switch in auto. I never change it. When you look at the headlight switch all of its lights are off. Simply turning the switch knob either direction then back to "auto" or "off" makes the chime stop. Then the switch has a light indicating the position the headlight switch is in.

I pulled codes and there are two headlight switch related codes. BCM B1533:08 which is "Headlamp Switch Module". The headlight switch has a LIN bus to talk to the BCM and if the BCM isn't able to communicate with the switch it sets this code. The second code was HVAC B162E:01 "Max Defrost LED". This code is set if the HVAC module can't tell the status of the LED on the Max Defrost button which is part of the headlight switch. It is also set if the switch is "stuck" - they say that means it has been depressed for more than 120 seconds continuously.

Seems like I may need a new headlight switch? Or maybe it'll be fixed with a software update, but the headlight switch is not an updateable module in any way shape or form. You need a hardware replacement with a newer part number and newer software.

Short video attached. You can hear the chime. That starts when the door is opened.

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[67 Stang Convertible]

I hope it does not have anything to do with the PAAK. Mine is at the dealer just finished it's PAAK update.

 

[breeves002]

I hope it does not have anything to do with the PAAK. Mine is at the dealer just finished it's PAAK update.

I truly doubt the RFA has anything to do with the headlight switch. It is just between the BCM and switch.

 

[BMT1071]

This is a weird tiny issue that has happened a handful of times only recently. This didn't happen for my first 4 months of ownership. It seems to have started to happen after my trip to the dealer for the PAAK update along with other updates but correlation isn't causation as there have been several OTA updates as well (though only to GWM and TCU).

What happens is I'll open the driver door and the chime will go off like you have the headlight switch in a position other than "off" or "auto". I ALWAYS leave my switch in auto. I never change it. When you look at the headlight switch all of its lights are off. Simply turning the switch knob either direction then back to "auto" or "off" makes the chime stop. Then the switch has a light indicating the position the headlight switch is in.

I pulled codes and there are two headlight switch related codes. BCM B1533:08 which is "Headlamp Switch Module". The headlight switch has a LIN bus to talk to the BCM and if the BCM isn't able to communicate with the switch it sets this code. The second code was HVAC B162E:01 "Max Defrost LED". This code is set if the HVAC module can't tell the status of the LED on the Max Defrost button which is part of the headlight switch. It is also set if the switch is "stuck" - they say that means it has been depressed for more than 120 seconds continuously.

Seems like I may need a new headlight switch? Or maybe it'll be fixed with a software update, but the headlight switch is not an updateable module in any way shape or form. You need a hardware replacement with a newer part number and newer software.

Short video attached. You can hear the chime. That starts when the door is opened.

There have been multiple posts about the chime. Most were just after picking the car up so it was assumed that the switch had inadvertently been set incorrectly. Your report makes it sound like a different issue. I have had this occur once on my car also. I am certain I didn't bump/change the switch position, and I am the only person who has been in the driver's seat since I picked it up last week.

 

[breeves002]

There have been multiple posts about the chime. Most were just after picking the car up so it was assumed that the switch had inadvertently been set incorrectly. Your report makes it sound like a different issue. I have had this occur once on my car also. I am certain I didn't bump/change the switch position, and I am the only person who has been in the driver's seat since I picked it up last week.

I believe you 100% I just hadn't seen a post about this specific issue. A quick search didn't turn anything up either.

Happening one time I would have thought it was some weird fluke, but it is quite odd it has happened multiple times fairly close together. It is the same style of headlight switch Ford has been using in all of the newer vehicles.

I do think it is a different issue, just not sure what the exact issue is. Looking at the codes it sounds like the headlamp switch just doesn't respond. Gets stuck in sleep mode.

It is an extremely simple wiring circuit. Power, ground, LIN to BCM, and then the defrost control and defrost indicator to the HVAC. BCM signal on the LIN bus should wake it up. I guess it could be an error in the BCM where it just doesn't send the message for some reason. Worst case it is the headlight switch itself...which would suck because I promise Ford would probably not want to replace it.

 

[BMT1071]

Interesting info here:
https://www.macheforum.com/site/threads/solved-chime-sound-whenever-door-is-open.6815/#post-188283

EDIT: I can confirm that no amber light was on when I experienced the fault.

 

[breeves002]

Interesting info here:
https://www.macheforum.com/site/threads/solved-chime-sound-whenever-door-is-open.6815/#post-188283

EDIT: I can confirm that no amber light was on when I experienced the fault.

My exact problem it sounds like.

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