Thank you! I think I understand.
Is Part 47070 (power brake booster) as an assembly, including the accumulator, called the ABS pump or is just the part that the water tower is mounted to called the ABS pump?

 

So this is what TMC calls those parts. Otherwise I personally do 'actuator' and 'pump assembly' and people understand me.

 

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Thanks, that really helps too. So depending upon what authority you use there are different names. But I think I now have a full understanding of the parts in question.

 

Have a blast

 

Had a brain fart, I meant nitrogen.

 

"Is that cooking spray??? - Yea. He thinks it's called 'hair shellac'".

 

Update: the accumulator aka abs pump 47070-50040, and brake actuator 44050-50110 were replaced and the same brake error lights still came on almost every morning, just as before, and would often not come back on again on restarts after it warmed up in the afternoon. The latest code is 1252.
Am curious what it is about the cold weather? or Mornings? At first I thought it was the rain, but that has been gone for a month. Is it a time thing about sitting over night? That doesn't work if the lights sometimes don't come on in the morning. The mechanic said he was on the phone with a Toyota master mechanic going through the 20 page electrical test that looks like the one that has been posted on ClubLexus here in pdf form. See attached.

Here is the latest diagnosis. Replace the Engine room no.2 Junction box, aka Junction Block because a relay is bad and you have to replace the whole fuse box thing.
Seems like a bad design there. Part 82720-50081
$600 for part and labor.
I sure hope this is the end of the brake actuator saga.

 

Hey guys, just letting you know that i have the 2007 LS460 with code C1253 and after struggling for 2 months, I finally got it fixed. I had to replace abs actuator part #04003- 45450 (latest updated version). Before that, dealer replaced with 2nd version (44050-50110) and the car ran for 1 week and code came back. Please don't waste your time like me ... install that last version !!! btw, i also replaced abs pump (47070-50040) as it will eventually fail because actuator problem. I had them both replaced by Toyota dealer, total parts and labor $3300 (i bought parts from Lexus). Note that all actuator version only has new part # on the outside box ... the old model # is always the same printed on the part itself. It looks like all 4 versions are rebuilt parts by manufacturer and so original part number is printed on the part itself regardless what shows outside of the box.

 

The conclusion of my brake actuator odyssey is that you really have to have this fleshed out by someone who has had this job turn complex before, or find someone who is willing to go through the Lexus dealer prescribed diagnostic protocol for the c1253 c1252 and related codes, which I think might take a couple hours, seemed like a really drag as my mechanic made it sound. I think a Toyota tech was walking him through it. Not sure. This testing is probably best paid for and done first, if you are not getting this done at the dealer.

While my mechanic had replaced ABS parts before, he wasn't familiar with how this job can go south in the diagnosis. You could also just start by replacing both the ABS pump and actuator, but sometimes the junction box has gone too, as in my case.

Some have recommended that finicky actuators can be set off by being in need of a proper bleeding using the correct techstream directions for replacing an actuator, while only doing a bleeding. This sounds like a great idea if you can find someone to do this. I have yet to read that someone here did that first AND did not come back later to tell us that the brake codes returned eventually. But I am obliged to wonder if there isn't some wisdom in that, given how my problem appeared with no previous symptoms, and no symptoms during, and being at least 2 years past my last brake fluid change. Although, my mechanic saw that my pump was barely working -- unless there is something about needing new fluid that could also create a sluggish pump.

If I had to do again, I would pay to get the above mentioned step-by-step diagnosis, not just code reading, from the dealer and confirm that they can tell me the ABS pump, actuator and Junction box had been included in the testing. If I felt like I could trust them and it wasn't horribly expensive maybe have them fix it.
If I decided to get it done cheaper I would find someone ONLY who had done these parts replacements before on a Lexus using Techstream. The guy I used had not before experienced the shell game that is this particular early 4th Gen Lexus actuator issue. I was his first. And that took a LOT of both of our time. He was a mechanic with plenty of experience, he just hadn't had THIS experience yet.
Either way, the extensive Lexus diagnostic steps would have to be done first. I think skipping that is where the surprises can begin.

 

You are correct about a few things and wrong about some other things.
First, you are correct about the part number only being located on the outside of the box. However with that said the black labeled part number located on the actual brake actuator part itself is not a part number at all, this number is for the electronic black box that's located on the side of the actuator and has nothing to do with the part number of the actuator.
You are also incorrect about the updated part number of the actuator as well. Brake actuator part number 04003- 45450 is a Lexus internal reference part number and all Lexus dealerships aren't allowed to enter this part number into your service paperwork for warranty purposes.
The New and latest and correct brake actuator part number is going to be part # 44050-50170. This is the part number that must be on the outside of the box! This part number sells for $1,700.00 for just the part and all Lexus dealerships know the per the Lexus service TSB - L-SB-0047-19.
I want to make sure everyone understands only the part number on the outside of the box matters.
Also, It's highly recommended to replace the ABS junction box with an internal ABS relay built inside of it which can't be removed without replacing the entire black box, the ABS brake actuator, and the ABS brake booster all at the same time.
If the brake actuator is failing from an internal leak, this will cause the ABS brake booster to continuously run, with the brake booster continuously running this causes the ABS relay inside the junction box to also continuously run "turn on and off" and they will cause the relay to fail.
You are correct about ONLY replacing the ABS actuator with the updated part and this is why.
Lexus has a known defect with all past brake actuators as the rubber seal on the old part numbers was too soft to hold the hydraulic fluid under pressure and if anyone didn't change the fluid every 30k-40k miles a white residue would build up inside the actuator and cause it to ultimately fail as well.
Never purchase those cheap $500.00 actuators made in China you will be doing it all over again in less than 2 years plus replacing the brake booster and junction box as well.
So for those reading this, I'm going to list the total cost to fix this correctly and before I do if you have the code C1253 Only replace the abs relay junction box first and go from there.
If you have code C1256 With other abs codes you'll need to start with the Abs acuator and go from there. Remember the best practice is to replace all three parts I've mentioned above.
Okay so here we go and it is expensive!
Parts ONLY - ABS BRAKE ACTUATOR NEWEST PART # 44050-50170 COST $1,700.00
BRAKE BOOSTER COST $950.00
ABS RELAY JUNCTION BOX COST $416.00
COST OF LABOR IS $200.00 PER HOUR LABOR
BRAKE ACTUATOR LABOR IS 4-6 HOURS LABOR
BRAKE BOOSTER IS 2 HOURS LABOR
BRAKE ABS RELAY JUNCTION BOX IS 1 HOURS LABOR
If anyone has any questions you can message me!

 

this is the actual ABS actuator part # outside of the box. This is the version that finally fixed my C1253 code

 

in case of need, what is the abs relay junction box part #? is it 82743-50050 ?
thanks!

 

in case of need, what is the abs relay junction box part #? is it 82743-50050 ?
thanks!

 

Boykie, I"ve been confused on this since yesterday. I posted on another thread, but I'm aware of the actuator being the main issue and the 10 year/150k extension from Lexus on the replacement. The pump is the $600 part I'm assuming based on the other responses. I see the abs module is $3k. That isn't a known failure, is it? I can't imagine having to spend $2000-$2500 on an acutator plus a pump and a $3k abs module. No matter how well off you are, that's hard to stomach.

Looks like SENSAY broke down everything that should be replaced. Has anyone had success with just the actuator? I called the dealer about this and they mentioned something about a secondary part, maybe the relay.

 

There are two parts to abs assembly - actuator and pump+accumulator. First seals in the actuator go. If you drive long enough after that (dtc or not) the pump+acc will go (running overtime, overheating etc).
Realistic price for an actuator is around 1k. Pump is little more.
I've never had to replace the fuse box, but I assume that goes third if issue is continually being ignored.