Premium LED Headlight Retrofit

Hello everyone, I have successfully installed the premium LED headlights (available on select SR models) into my 2021 SV Premium that came with regular halogen headlights. It is possible, you will just need basic mechanical and electrical knowledge. You will need to be able to remove the front bumper cover, the battery, the headlights, and be able to solder or crimp wires together.

2021 Nissan Sentra SV Premium with added Premium LED headlights.

Preparation
The connectors are different between the two headlights. The halogen headlight has two connectors; a 4 pin main connector and a 2 pin low-beam connector. The premium LED headlight has one 8 pin connector. This means you will need to splice in a new connector on each side. I bought a pair of aftermarket 8-pin plugs and sockets. If you can find the matching Nissan connectors, you can use those. I had no luck finding or verifying the correct matching connector.

Premium LED headlight 8 pin connector.

Aftermarket 8 pin plug and socket connectors purchased from eBay.

Removing the Bumper and Headlights
You may remove the negative battery terminal connection for safety before you remove the headlights. Once you have your connectors, you can start by removing your front bumper cover and headlights. There are pop clips on top of and underneath the bumper cover. There are four 10mm bolts on each side underneath the bumper cover as well. Lastly, there are two hidden 10mm bolts (one for each side of the bumper cover) behind the wheel well liners by the flange of the bumper cover near the top. You can use a flathead screwdriver to sort of peel back the liner exposing the bolt. Be careful as this area is a major pinch hazard for fingers. The bumper can now be pulled out of its retaining clips near the sides by the wheels. The bumper cover should just pop out with gentle pulling. The headlights are each held in by four 10mm bolts. The connectors on the back of each headlight can be removed using a flathead screwdriver and slight prying. There are two connectors to be removed from each headlight. One is the main connector with 4 pins and the other is a 2 pin low beam connector.

Wiring
I am about to save you so much time. Here is the list of the matching wires between the car's harness and the premium LED headlight as well as their functions:

Driver's side

Passenger side

Using this information, you can go ahead and crimp or solder on both ends of your connectors onto your car's harness and the headlight. You may notice that there are two yellow wires on the passenger side car harness. You will have to find out which one is the high beam wire and which one is the turn signal wire. Simply use a multimeter and find which wire reads 12V with the high beams on. Logic tells you the other yellow wire is the turn signal. You can wrap a little piece of electrical tape around one of them to help identify it later on.

You may also notice that there is an extra wire from the premium LED headlight, the red/black wire. This wire will be unused for this installation. From other light research/hearing things other people say, I presume this wire to be some sort of internal headlight temperature sensor that when detects a high temperature, the car will reduce power to the headlights slightly. I have not had problems yet but will update this article down the line if I do. LED headlights draw considerably less power than halogen headlights, with the latter not using an internal temperature sensor. The car has no way of making use of the wire anyway, as the models with factory installed premium LED headlights have the computer logic that comprehends the signal, as well as having a dedicated wire in the wire harness.

Soldering on the aftermarket connector to the LED headlight.

Completed harness on LED headlight.

Supplying the DRL's with 12VDC Accessory Power
The car's factory harness supplying the headlight does not have a wire that supplies 12V whenever the car is turned on. If you want the DRL's to work as intended - are on whenever the car is on, then you will need to add a wire that supplies this power. However if you want the DRL's to turn on only whenever either the parking lights or low beam headlights are on, then you could just wire to those respectively without issue. In that case of course you wouldn't need to run an additional power wire. In my case, I had already ran a 12V wire for my fog lights so I just tapped off that. Both my headlight DRL's and my fog light DRL's are on whenever the car is on. If you opt to just tap power off the parking light or low beam wires, then you can skip to Turn Signal Hyper-Flash.

On the back of the headlight, you can find a list of 7 different functions with their associated voltage and power ratings. The headlight internally has a means of stepping up voltage so you do not need to worry about supplying 18 or 22V, just standard 12V. Using Ohm's law, you will find that the DRL's consume just 0.36A each.

Functions (Noted from the back of the headlight)
LB (Low-beam) 11.2V / 31.7W
HB (High-beam) 18.8V / 13.5W
Fan (Cooling fan) 12.0V / 0.8W
DRL (Daytime running lights) 22.5V / 8.2W
PL (Parking lights) 22.5V / 0.8W
FTRL (Front turn-signal lights) 12.0V / 10.0W
SML (Side marker light) 13.5V / 2.1W

This means you can supply power to them using a fuse tap off the power port fuse slot that is located by the driver's left leg. You can buy a fuse tap from any auto parts store. You can use a 2A or 5A fuse with it. Feed the power wire through the firewall via the wire harness grommet behind the brake pedal and behind the battery. This is when you will remove the battery to better access the grommet from the engine bay. Carefully cut a little slit in the grommet using a razor blade, and feed your power wire through. It is a bit tedious, just keep trying to poke it through. You may need to cut a bigger slit if you are having a hard time pushing the wire through. Now you just splice on another wire and run them to each connector using the diagram above. Tapping off the power port fuse allows the DRL's to be automatically turned on and off when the car's accessory power is on or when the engine is running.

Turn Signal Hyper-Flash
Upon install, the turn signals will hyper-flash. The factory halogen turn signal bulb draws considerably more power than the LED turn signal in our new headlight. The car's flasher module detects that the turn signal isn't drawing the normal amount of power, which would normally indicate a burnt out light bulb. Hyper flashing is actually a built-in function of the flasher module to alert the driver that something is wrong with the turn signal (a bulb is burnt out either front or back). I purchased Sylvania load resistors and wired them in parallel with the turn signal circuit to mitigate this problem. I just loosely placed the resistors within the front bumper metal structure channels, with one wire poking out one of the holes about 6 inches in to lock it in place. This easily fixed the issue and I have no more hyper-flash.


The factory halogen headlights before upgrading.

Mid-day full sun.

Nighttime frontal.

View of increased nighttime clarity.

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