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Upgraded 2019 to LED fogs, now they're no longer working...

TheMadDutchDude

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Hey guys,

I upgraded my 2019 from the stock halogens to the OEM LEDs and they used to work just fine, albeit the left one would flicker rapidly... the right was fine. This morning, the right came on momentarily when making a right turn and then shut off.

If I am not mistaken, I think it is because the BCM has finally realized that the lights are not using the correct resistance it is programmed for, so it is shutting them off for "safety" ... is that correct?

If so, I've been reading that I need to get an OBD2 programmer. How many of you have done this? Did you buy one from Amazon? I have been looking at this one: https://www.amazon.com/OBDLink-Blue...=1635162953&sprefix=obdlink+mx,aps,126&sr=8-3

Lastly, if that is what I need, how do I get to the OBD2 plug? I believe it's behind the lighting controls (under the wheel), but I'd like to know if that panel is easy to remove rather than trying to fiddle with the cables from underneath. What has been your easier experience?

Many thanks!
 

MannyN

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What did you replace? Just the bulb or the complete housing? If you replaced the whole housing, then you have to switch the pins in the connector to reverse polarity. Also, you will need to tell the BCM that you have Fog LED's. You'll need AlfaOBD, the bypass cable and an OBD Dongle to program.
 

TheMadDutchDude

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I switched the housings, OEM for OEM. Funnily enough, they worked fine this afternoon on the drive home. I think the lower temperature in the morning caused a change in resistance, big enough to think there's a short and it shut itself off for safety. Just a theory (coming from my IT background) ... not too sure!

The polarity is reversed - that's what the manual stated to do.

I've ordered the plug above and I'm hoping for some good results. I'll let you guys know what happens. :)

I figured it is useful to have a tool like that, it's always nice if you're changing something or you want to read a code (if/when it throws one) before deciding to go to the dealership.
 

MannyN

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You still need the bypass cable, otherwise you can not program the BCM, you can just read and clear codes.
Get this cable and you good to go.
 

TheMadDutchDude

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I'm thinking I messed up... is the thing I ordered only a scanner, not a programmer? If so, I'll send it back and grab the proper one. I guess I just need to look into it more as I was a little hasty with the trigger pulling.
 

ram813ltd

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a programmer is high dollar. talk to the led manufacturer or retailer. they know what works and doesn't.
 

Jimmy07

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I'm thinking I messed up... is the thing I ordered only a scanner, not a programmer? If so, I'll send it back and grab the proper one. I guess I just need to look into it more as I was a little hasty with the trigger pulling.
If you already ordered the MX+ and the bypass cable MannyN linked, all you need is AlfaOBD for Android or windows, or Jscan if you are strictly iOS.
 

TheMadDutchDude

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I wasn’t sure if that cable would do the trick. I’ll grab one and go from there. 😁
 

Renegade3

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Having the same issue after a year. I've found that if I leave my fogs off at startup on cold mornings, then turn them on after about 10 minutes they're fine. Try that and see if it works for you.
 

Jimmy07

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Having the same issue after a year. I've found that if I leave my fogs off at startup on cold mornings, then turn them on after about 10 minutes they're fine. Try that and see if it works for you.
This is because the PWM duty cycle is low on cold starts because of load shedding. The low duty cycle causes the BCM to not detect the resistance of the halogen bulb it is looking for, and shuts down the circuit. Changing the BCM setting to LED front fog lamps present, like it is for factory equipped LEDs, will shut off the PWM and correct this behavior.
 

TheMadDutchDude

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TheMadDutchDude

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Well, I finally got round to doing it last night. I had to pay the extra $49 for the AlfaOBD software and modify the kids Fire tablet to have the Play Store... but we are done! No more flickering, no more random turning off, just working as they should. Process took minutes... probably took me longer to figure out that I needed the software (and to modify the tablet) than anything else.

Thanks for your help, fellas. Really appreciate it! :)
 

Dfinnicum

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Not meaning to revive an old thread but what all settings did you have to change in alfaobd to get this to work
 

ZombieSlayer

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CBC Features: LED Front Turn Lamps Present- Yes
CBC Features: LED Front Fog Lamps Present- Yes
CBC Features: LED Dedicated DRL Present- Yes
CBC Features: LED Low Beam Lamps Present- Yes
CBC Features: LED High Beam Lamps Present- Yes
CBC Features: LED Front Park/Marker Lamps Present- Yes
CBC Config I/O: Right Dedicated DRL Lamp/Right Signature LED Present/Right Front Turn Signal #2/Headlamp Leveling Output Present- YES
CBC Config I/O: Left Dedicated DRL Lamps/ Left Front Turn Signal #2/Left Signature LED Present- YES
CBC Config I/O Usage: Left Front Lamp Diagnostics Present - Pin F25- Yes
CBC Config I/O Usage: Right Front Lamp Diagnostics Present - Pin F28- Yes
CBC Extern.Light Calibr.: Signature Light Present- Yes

Courtesy of @Jimmy07 :D
 

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