I had one bulb go out and replaced both at the same time. That's recommended, by the bulb manufacturers I'm sure! Your bulbs are the high intensity type (high $ too). The bulb and attached metal box (high voltage source) are one unit. Here is what I bought https://smile.amazon.com/gp/product/B076BTWSP5/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

Since it’s the LED DRL they’ll have to replace the whole part out.

 

Use an online catalouge page like GM parts , put in your vin and see if its one unit or more for your specific model. DRL has a dedicated ballast.
HIDs also have another ballast but thats for the xenon headlamps which takes philips (
or equivalent) 43volts 35watts bulbs (D3S)

 

Hello I am new to the Escalade Platinum ESV and how do I know if it’s Premium or Standard? I need my system in my ride I don’t care in having onstar or the steering wheel stuff to turn up and down! Can you please help me????

 

The diode for the DRL can be replaced. See video's below. They are for an ATS and XTS, but I think the process would be the same. You would have to look up the part # for a CTS. Dealers would have you replace the entire headlight unit which is big $$$, but not necessary.

 

Did you ever figure out a way to fix this? I'm having this same issue.