Hi there,
I just got code from around 304 000 km.Not bad considering 4 cylinder engine.
Good thing was that you are still able to drive your car on petrol engine 🐤 even if all hybrid part was failed.
Limp mode ,like Mercedes.Still I like Lexus but don't like engineers which design hybrid battery.
Anyway it was for educational purposes good .I will show you how we get around this problem with couple hybrid battery cells from 2014 Camry hybrid for free ,from junk yard.
Everything started with famous warning light,check engine ,etc etc.

 

After scan was done ,code was very familiar.now question was which cell was making trouble here.

Here is data showing our cell number 11 completely failing.

 

Now dilemma was if we will buy new battery or rebuild the old one?? Well put money aside ,we wanted to show Lexus that is still possible to mix and match battery cells from other cars and make this Lexus still alive.

 

You can see some pictures how job was done.Please be careful if you doing yourself because of high voltage ,don't disregard safety measures and equipment needed to perform this task in safely menners.

One more of pictures showing terrible gas mileage.


We disconnected 12 volts battery in the trunk on the right side ,remove all panels and expose hybrid battery as you can see.NOTE this is different setup than on my GS 450h .Hybrid disconnect orange switch was hiding behind metal cover.That is not good design on ES 300 h ,just imagine in case of accident you can't remove hi voltage orange plug unless you have 10 mm socket ready to remove two nuts.THAT IS VERY STUPID DESIGN . GS 450 h has easy access to orange switch and RX 450 h easy access too.

Here is better look of hybrid battery.WHERE IS THE ORANGE SWITCH ?????

 

We started removing sets first,seat belts brackets,and very ,very ,very carefully yellow airbag connector.

Seats ,sorry for dark image here.


Air bag connector,must be removed before you remove back of the seat .here take your time ,don't brake any pin please.

After disconnecting remove other side of that connector from metal bracket attached to seat.


We have used plastic trim removal tool here ant it was perfect.nothing broken.

Next we did was seat belt clip removal.NOTE HERE there are two optios. 1 .pop up plastic clip holding seat belt ,be careful it can be broken easy if you apply more force. 2.unscrew clip with philips screwdriver .two screws on each seatbelt clip ,left ,right and Middle one.

 

Next was back

Seatbelt option one.
seat removal
Seatbelt clip option two removal.

To remove back seat we had to push up than pull towards us , carefully not damage ing plastic retainer where hooks from seat is going too.

Back of the seat you can see those hooks .

The whole seat after removal.

Next step was removal of connection on 12 volt battery and orange high voltage safety switch ,hidden behind shield secured with two 10 mm nuts.

 

Use high voltage certified gloves to remove orange connector.

 

Next step was removal of the cables from inside seat area.

We have removed metal shield and just pulled out both cables and one white connector.

 

White connector.

We have removed bolts holding traction battery to the car frame.

Two more on the front and after that we pulled battery out.NOTE this should be two man job because this battery is very heavy.

 

Finally traction battery was out of car.now we removed fan and the rest of connections and big cover in order to get access to the hybrid cells.


Fan was disgusting so dirty ,we had to clean it up.

This was great time to clean intake vent by the rear driver side door as well.

 

1/2 hour cleaning and drying ,it was ok at the end.All ducts and small filter was cleaned too.No more restrictions in airflow.

We continue with removal main cover and everything else attached to it as you can see from the pictures.

 

Poor connection on main cable.disgusting oxidation.must be cleaned,and nut replaced with new one.

NOTE use only insulated socket and extension to protect your self .

 

NOTE VERY IMPORTANT REMOVE HEAT SENSOR BEFORE REMOVING HOUSING.

Removed cover put on safe and dry place.

 

And here it is fully exposed hybrid battery .

And another issue ,all connector's were oxide . cleaning with vinegar and baking soda is a must.

 

We did remove torsion bracket and remove our bad cells from block 11 and replaced with Toyota Camry cells.

We did remove all bus bars and replace them with new ones.

So this is how we figured out which block is block 1 we follow ed negative terminal and it was here.from driver side power supply unit and fan was on that side too.i hope we are not wrong here.