What is this XY401 reference between the DRL harness and BCM?

[ecidiego]

XY401 on the lighting sense wires...is that some sort of inline disconnect?

Has anyone ever ran this wire? What terminals would I need from the body side DRL/Turns connector to XY401 to BCM C6/F?

I've got an easy path to run this wire but don't understand how to pin it.

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[ecidiego]

I guess I don't understand the diagram.... Wire 1 on DRL. Here is a pic of the connector from body harness to DRL harness. Body harness on top. This is the left DRL.

This is the diagram:

I have the WH/OR wire on Wire 1. No BG/BN wire as the Premium ( factory LEDs ) shows for Wire 1. Is the diagram saying Premium would have BOTH those wires together on Wire 1? Or is it saying the Premium has no WH/OR wire there.....just the BG/BN?

The BG/BN then runs off to XY401A, then on to BCM C6/F25. My WH/OG wire goes off to BCM C1/A10.

I'm confused because I thought I would add a missing wire not used on the factory halogen harness....but the diagram shows Pin 1 on the DRL harness being used twice for the Premium ( factory LEDs ). Do I tap off of my WH/OG wire and run it to the BCM? Remove the WH/OG wire?

@Jimmy07 you got a quick 10 second answer? Haha. The purpose of this is to use the DRL Diagnostics abilities in the BCM. As is - if I turn those on I get errors as I don't have the fault sense wire.

 

[ecidiego]

I guess what's bothering me is the Fault Sense Wire from the LED DRLs is wired to the Side Marker Control circuit on my BCM at C1/A since this was a halogen truck. Obviously not supposed to go there now. It's supposed to go to C6/F to an entirely different input on the BCM.

Question is....will it hurt anything? Lights all work fine. Diagnostics are disabled to cure the hyperflash/turn signal out since I don't have the Fault Sense circuit connected. It does throw two codes tho if I set LED Side Markers Yes....says there is a short circuit at the side markers. Obviously isnt.... the BCM just sees ground I am guessing on its Side Marker Control circuit which is now connected to Fault Sense at the lights. If LED Side Markers are set No ( even know they're LED and work either way ) , no codes.

No harm no foul leaving as is?

 

[Jimmy07]

Pin 1 side marker control is not used on the front LED DRL lights. You would remove the wire from pin 1, and insert a new wire in that position to run to the BCM for the light fault sense circuit.

 

[Jimmy07]

I guess what's bothering me is the Fault Sense Wire from the LED DRLs is wired to the Side Marker Control circuit on my BCM at C1/A since this was a halogen truck. Obviously not supposed to go there now. It's supposed to go to C6/F to an entirely different input on the BCM.

Question is....will it hurt anything? Lights all work fine. Diagnostics are disabled to cure the hyperflash/turn signal out since I don't have the Fault Sense circuit connected. It does throw two codes tho if I set LED Side Markers Yes....says there is a short circuit at the side markers. Obviously isnt.... the BCM just sees ground I am guessing on its Side Marker Control circuit which is now connected to Fault Sense at the lights. If LED Side Markers are set No ( even know they're LED and work either way ) , no codes.

No harm no foul leaving as is?

I would wire and configure the BCM correctly. The side marker control circuits still need to stay enabled on LED equipped because they are spliced, and still control the side markers on the rear. You’re probably getting a short fault set every time you use the turn signals because the light fault sense goes to ground normally, whereas now you’re front side marker circuits are actually shorting to ground inside the front lamp assembly.

 

[ecidiego]

I would wire and configure the BCM correctly. The side marker control circuits still need to stay enabled on LED equipped because they are spliced, and still control the side markers on the rear. You’re probably getting a short fault set every time you use the turn signals because the light fault sense goes to ground normally, whereas now you’re front side marker circuits are actually shorting to ground inside the front lamp assembly.

Thanks as always Jimmy.

I will get it going. Would you guess ( no crystal ball ) it's safe to use it this way in the interim, other than the BCM complaining and the fault sense inop in the front? I also think I'll go straight to the BCM and not bother with XY401A. I can't even find it.

 

[Jimmy07]

Thanks as always Jimmy.

I will get it going. Would you guess ( no crystal ball ) it's safe to use it this way in the interim, other than the BCM complaining and the fault sense inop in the front? I also think I'll go straight to the BCM and not bother with XY401A. I can't even find it.

I would say so, I’m pretty sure there are many others running around like this, unbeknownst to them.
I’m gonna guess that the fault sense wires are already populated in the body harness (BCM to xy401). Here’s the connector location if you want to check:

 

[ecidiego]

Got it, probably there from BCM to XY401A, but not there XY401A to DRL. Oof. My hands are gonna bleed. That looks very rough to get access to but I'll go for it. If you're ever out in San Diego I owe you a lot of beers or soda or whatever you prefer!

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