My 2023 G90 battery has completely died half a dozen times. It has two unsolved problems... the battery randomly dies and non-existent, phantom, cars are detected when using Highway Drive Assist (HDA). The phantom cars cause the HDA to not work properly. Working through a lemon law buy back now. It has spent about 3 of the last 6 months at the dealership service department for warranty repairs.
The battery dies randomly from time to time. Been to the dealer for service three times for the battery, no fix yet. To get a replacement battery can take weeks because it is an OEM part. AutoZone, Pep Boys, etc. do not have a replacement battery.
I keep a lithium jump battery in the trunk and a 2nd at home. I swap them about every month so, the one in the trunk has a full charge. A few notes...
1. Push the front of the door handle inward so the rear of the handle will pop out a little. Now you can grip the handle to pull it out.
2. Remove the door handle panel (bottom side and to the rear of the door handle). Take notice of the orientation of the panel for reinstall.
3. Hold the mechanical key from the side to fit it into the opening, then into the keyhole.
4. With your right thumb and fore finger, turn the key counterclockwise to about 11:00 on the dial. Keep it turned to that position.
5. Pull the door handle energetically with your left hand. The door lock is electric too, so pulling the handle substitutes kinetic energy to unlock the door.
6. Now inside, you can open the hood.
7. Remove the plastic panel above the fuse box. It has a plastic removable (barely) rivet towards the back of the panel.
8. Remove the fuse box lid by pushing the left and right plastic latches.
9. Turn off the jump battery device.
10. Attach the negative lead of the jump battery to the grounding bolt just aft of the fuse box.
11. Attach the positive lead of the jump battery to the silver metal strip inside the fuse box.
12. Turn on the jump battery device. It may take a little time to energize the system (about 20-30 seconds in my case).
13. Start the car.
14. Turn off the jump battery device.
15. Detach the device's leads and check the charge level of the device.
16. Reinstall the fuse box lid and the plastic panel (with the plastic rivet).
17. Reinstall the door handle panel.
18. If you have the 3.5T E-SUPERCHARGER model, the 12-volt battery is in the trunk BENEATH the supercharger battery. So, it is difficult to access. You may even have to remove the supercharger battery to access the 12-volt battery.
19. If you let someone else drive the car, be sure to point out the manual door latch inside the car. On one occasion, I could get into the car, but the battery was too depleted to start the car. In trying to start the car the battery went completely dead and the door opening button became inoperative. I needed to use the latch handle in the door storage pocket to exit the vehicle.
CAUTION: If you download the online G90 manual for jump start instructions, they are wrong. The manual mis-labeled the terminals. It instructs you to connect the positive lead to the grounding bolt and the negative lead to the silver metal strip in the fuse box. This is backwards of course. It should be positive to the fuse box, negative to the grounding bolt. Not everyone will know the manual is wrong. According to the Genesis dealer, if you follow the manual's instructions you could fry the car's electronics. I don't think there has been a positive ground car in the US since 1955 (6-volt, positive ground Ford Thunderbird). I don't recall the jump start instructions being present in the car's physical user's manual and of course the Nav system is dead, so no access to information there either. That's why I went online (at the Genesis website) to download the digital version.
CAUTION: Don't leave home without your emergency mechanical key. One of the two keys should have a numbered tag. Don't lose that tag as it is may be needed should the key(s) ever be lost. The Genesis engineers have great confidence you won't ever need the emergency mechanical key so, they did not embed it in the FOB. Bad idea. The FOB is HUGE. So, plenty of room to embed the emergency key. Every other manufacturer I know of embeds the emergency mechanical key in the FOB (Lexus, Audi, etc.). Anyway, I have to travel about carrying that key on a key ring.
I hadn't heard of the non-functioning trunk release. I haven't tried the trunk release as the car is still at the dealership awaiting completion of the buy back.
My G90 has many electrical issues:
1. While driving the car it sometimes resets all my settings to factory defaults. Takes a while to get it set back to my settings as there are a lot of settings. Some buried deep in the Nav's menu system.
2. Randomly, the dynamic radar distance setting will reset along with the HUD tilt and height settings.
3. Of course, the recurring random dead battery problem.
4. The retracted outside rear view mirrors will independently deploy in the middle of the night while locked in the garage. I'm wondering if that has something to do with the recurring dead battery. I purchased two
Faraday bags to keep the FOBs in while at home. When in the
Faraday bag, the FOBs cannot communicate with the car. The
Faraday bags did not stop the dead battery and mirror deployment issues. I lock the car in the garage to avoid the iPhone app warnings the car is unattended and unlocked. And also, to avoid smacking into the extended door handle walking by the car in the garage. Away from home, when unlocked, the car will keep the door handles fully extended thus announcing to everyone that the car is unlocked and accessible. Another bad idea. Perhaps the handles should retract when unlocked after a period of time, then extend when the FOB or phone is approaching (or when the unlock button is pressed for passengers to gain access).
5. Replacement batteries are difficult to source. I think it is an OEM part outsourced to Interstate Battery for distribution. Replacing my battery, once the dealer could get one, did not solve the problems.
6. Every time I intend to use the car, I have to go to the garage 30 minutes before leaving to confirm the battery is not dead. Otherwise, I'm late for whatever event I'm going to. The 30 minutes gives time to get into the car to open the hood to jump the battery and to keep the car running for 20 minutes to charge it back up (some). A monumental pain. A waste of time and fuel. Not thinking this is helping reduce global warming.
7. The radar HDA problem persists. They have replaced the radar sensor responsible for the field where the phantom car shows. They have replaced the wiring harness connecting the sensor to the controller. They have replaced the controller. They have recalibrated the sensors several times. Nothing has fixed the problem. Recently they suggested they may replace the front bumper as it may have too much paint on it. Seems like grasping at straws. The problem got progressively worse over the months. It used to be random, often taking up to a few hours to malfunction. Now it happens every time I engage HDA. To replace the controller, the technician had to disassemble part of the dash. That's scary! I'm wondering if sometime down the road a dash rattle will develop. Icke.
8. Although not technically a warranty problem as it works as designed... The "Approach unlock" feature is useless for me. When activated, every time I approach the car the doors unlock, and the handle extend and after a period of time with the door not opening will re-lock. I'm often around the car in the garage while doing other things, and the car repeatedly unlocks and re-locks. I suggest a better design would deactivate approach unlock after a couple of successive unlocks without the door opening. Then re-activate approach unlock once the car door is opened.
It's a beautiful car. But beauty runs only skin deep in this case. I won't be buying an Electrified Genesis, that's for sure.