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Has anyone here changed the battery yourself on your 4th Gen. Lexus GS 350? If so, any tips on removing the cables that attach to the positive terminal from the battery case? Not sure why the Lexus decided to attach the cables to the side of the battery case in the first place. I saw a video on how to do this on Utube but it was not entirely clear on this point.
Thanks in advance.
I did it myself and there was nothing special you needed. However I did not put back the plastic battery cover. Not needed and didn't fit my interstate battery from Costco.
Tips:
-Leave your key fob in the car with the windows down and unlocked. If the car locks while your installing the new battery, once the system senses power as you connect the terminals to the new battery, the passive alarm/horn will immediately sound.
-When you remove the old battery, its negative first, then positive. When you install the new battery, positive first then negative.
-Be patient and don't get too flustered. I had to fight with things a bit for a good 15min before I realized that the OEM cage is more of a headache and if it breaks, its not the end of the world. If you buy certain aftermarket batteries, the OEM plastic may not even fit around it.
-Once you have the new battery in, if you have your foot on the brake and try to start immediately, the car will likely crank the engine but immediately shut off. Instead, i recommend that you press the start button once, then twice without your foot on the pedal to get to the system startup without cranking the engine. The system startup will begin to initialize on-screen - you'll want to let it do its thing. Once complete, you can hit the start button again to shut things down.
-Now you should start the vehicle as you normally would with your foot on the brake+start button.
-There is an ongoing campaign where A/C Servo motors could go bad when you change the battery or may need reinitialization. If the servo motors go bad after you change your battery, you'll have issues with your air conditioning as a result. See this thread: https://www.clublexus.com/forums/gs-...l#post11032537
IMHO the biggest challenge is the wiring harnesses which are attached to the OEM battery cage/cover on the positive terminal side. These are the most difficult to remove and any vids you see on youtube make it seem like its a piece of cake. They don't show you the part about how to actually detached the upper harnesses on the positive terminal side from the OEM plastic cage!
Once the negative and positive terminals are set aside, you'll realize that the bottom tab/connector can be slid off by applying pressure using a screwdriver to the tab and then sliding over (black/white arrow in image below).
The wiring harnesses attached at the top don't necessarily each need to be detached separately - you can see that I simply slid the OEM plastic cage and wiring harness apart to get it to removed from the OEM plastic battery cage (blue/white arrow in my image below):
@EGLIDE the post above is all you need to know. Study it carefully, the point about letting the car sit in acc mode without starting is very important.
When you make and break connections, do so swiftly and with confidence, don't let it arc longer than necessary.
To all that replied, thank you.
I carefully followed AJLex19’s instructions without any significant issues. I was able to separate the positive cable trunks from the plastic battery cage and my OEM replacement battery swapped out seamlessly with the cage intact and back where it was before I started the job. My only little issue was bolting down the battery hold down bracket because the piece that the battery bracket bolts to kept slipping down behind the battery, but I managed to figure it out.
After I started the car, I put the a/c on the coldest setting and did not hear any unusual sounds so hopefully the a/c servo motors were not affected. The vents also appeared to be operating at proper capacity.
I still do not understand the connection between the battery replacement and the a/c servo motor issue. Does anyone know the answer to that question?
Also, does anyone know what GS model years are included in the free repair and how many vehicles are actually affected by this issue?
Thanks once again.
To all that replied, thank you.
I carefully followed AJLex19’s instructions without any significant issues. I was able to separate the positive cable trunks from the plastic battery cage and my OEM replacement battery swapped out seamlessly with the cage intact and back where it was before I started the job. My only little issue was bolting down the battery hold down bracket because the piece that the battery bracket bolts to kept slipping down behind the battery, but I managed to figure it out.
After I started the car, I put the a/c on the coldest setting and did not hear any unusual sounds so hopefully the a/c servo motors were not affected. The vents also appeared to be operating at proper capacity.
I still do not understand the connection between the battery replacement and the a/c servo motor issue. Does anyone know the answer to that question?
Also, does anyone know what GS model years are included in the free repair and how many vehicles are actually affected by this issue?
Thanks once again.
@EGLIDE Glad it went well! Seems to be a common issue with the servo motors on many toyota/lexus vehicles over the years including cars that have low miles or are just a few years old. You'll find a bunch of threads on this topic on this very forum. Doesn't seem to by any rhyme or reason for the failures from what i've read/heard. In many instances though, the motor will prematurely fail regardless of changing the battery or just normal/common use. I was just giving you the heads up in case it happened to you...Lexus would try to take care of you with that support program.
The problem affects pretty much all 4GS models from 2012-2020 - many of us received a letter from Lexus outlining the problem. I didn't initially receive a letter but I called the corporate # and spoke to someone who was extemely helpful. I then received the letter within 3days.
Battery went dead out of nowhere and checked it with the multimeter and it showed .4 volts lol, couldn't boost it or charge it, so i got a MTP-24 interstate battery with an extra 150CCA over the one that was replaced, had no issues but definitely made sure not to start the car until the computer had a chance to initialize again, hopefully this information helps someone out. Ditched the battery cover box as it wouldn't fit.
Battery went dead out of nowhere and checked it with the multimeter and it showed .4 volts lol, couldn't boost it or charge it, so i got a MTP-24 interstate battery with an extra 150CCA over the one that was replaced, had no issues but definitely made sure not to start the car until the computer had a chance to initialize again, hopefully this information helps someone out. Ditched the battery cover box as it wouldn't fit.
3 year old battery and started noticing 1st starts in morning were slightly challenged last few days.
Changed the battery today and "made sure not to start the car until the computer had a chance to initialize again".
Worked out like a charm.
3 year old battery and started noticing 1st starts in morning were slightly challenged last few days.
Changed the battery today and "made sure not to start the car until the computer had a chance to initialize again".
Worked out like a charm.
Do you need to have the ignition on for it to initialize, (i.e. press the start button without foot on the brake)? Just wondering for future reference as I don't need a battery right now.
Do you need to have the ignition on for it to initialize, (i.e. press the start button without foot on the brake)? Just wondering for future reference as I don't need a battery right now.
Yes, push it twice without foot on the brake. You'll see the radio boot, it takes a short while. My suspicion is that people report losing their radios when changing batteries because they crank as it's cold booting, corrupting a file.
Yes exactly.
However I did have a memory saver on the terminals.
Did the computer initialization (2 pushes of the start button w/o brake pedal), more for mitigating the potential servo motor failure.
05-01-21, 03:22 PM
DIY battery replacement on 4th Gen. Lexus GS 350
