ABS, Brake, Amber Triangle, Traction, Parking all lights on

The stroke simulator is part of the hydraulic braking system; getting no fluid from it indicates a hydraulic braking system issue of some kind.

The C1203 is shaping up to be a tough nut to crack. The brake ECU has to 'like' the power management control ECU, the body ECU, and the yaw/acceleration sensor that it is teamed up with. Exactly what makes it not 'like' them isn't clearly stated in the manual, nor what can be done about it.

 

I don't think the stroke simulator in a Gen 3 is available separately; it's just part of the actuator assembly.

One should avoid the temptation to somehow reify "the regen brakes". There's no such physical thing. There are just the brakes, and the brake ECU communicates with the power management control ECU, and says "driver wants to slow this much, how much can you do?" and the power management control ECU says "I can slow this much using the powertrain" and the brake ECU says "thanks, I'll use the brakes for the rest".

They won't 'fight' each other in such a way as to rattle the engine. The slowing effect of regen in the powertrain is like downshifting in a conventional car. Blending the two is like downshifting in a conventional car and using the brakes. They don't fight.

This wiki page details how you can obtain all the technical information you are looking for.

 

In a Gen 2 Prius, the stroke simulator is a separate part. But here in the Gen 3 forum, if you are writing about the 2010 Prius mentioned in your profile, it is not. It is the vertical, cylindrical part of the actuator assembly shown here, with the bleed screw visible at the top.



... which perhaps invites the question, if you were unable to bleed fluid out of the stroke simulator earlier, and you were thinking of the stroke simulator as some other separate part, what exactly you might have been trying to bleed ...

Your most recently posted codes were C1203, C1345, C1392. Is that still the situation? No communication codes in that current bunch. But still that C1203, which is going to be an obstacle.

 

Ok, what I meant was that the actuator is only available as a complete assembly from Toyota.



I can't really help if eBay sellers are dismantling used ones and selling the pieces.

When you say "I only replaced the electro-hydraulic actuator of the assembly", does that mean you bought an incomplete actuator assembly from an eBay seller and attached your own stroke simulator to it?

 

My theory, based on many similar problems, is your head gasket started leaking the first time you heard the rattling and eventually became bad enough to blow white smoke. In some cars this process can take months. Initially the head gasket seems to seal itself with heat expansion of the block and head. Coolant loss is not obvious for weeks.

Regen braking is simply an electric generator controlled to generate a variable amount of current which is regulated and routed to the hv battery. A large regen current causes a large amount of slowing through the planetary gears to the drive wheels. It is clean and smooth. It has nothing to do with an aggressive engine rattling. The rattling is a severe misfire that makes it hard for the transaxle to synchronize with the engine. The typical head gasket coolant leak causes a misfire for five or ten seconds before the fouled plug clears and the engine smooths out. Initially hg misfires are only after an overnight coldstart. Eventually they get big enough to rattle every time the engine starts as you drive down the road. At some point it is so bad coolant flows into the cylinder and burns into white smoke.

Assuming the rattle still occurs as the engine kicks in, the odds are your head is warped, the block is warped, a piston is bent or a head bolt is loose causing a second head gasket problem. A borescope inspection of the cylinders will often show one cleaner piston caused by the leak. Otherwise a bad coil or spark plug could cause the rattle but generally will be more constant and will throw a misfire code.

The Brake Pump and Master Cylinder assemblies have several common issues. First, these things go bad due to a design flaw. Second, there are two parts in a gen3, the master cylinder with ecu, stroke simulator and abs as one unit and the brake pump and accumulator as a second unit. The brake pump is usually the first to go with a leak in its internal diaphragm.

There is a complication when trying to replace the master cylinder assembly with a used part. There are two different assemblies for each gen3 year and still another version for a gen3 v wagon. By 2012 the master cylinders changed so gen3 2012s and up won't work in a 2010. The ecus in these assemblies have to be right.

So your choices are one of the two hatchback versions from a 2010 or 2011. Ebay and junkyard sellers don't know this and may make an even worse mistake. They often take a housing stamp like 47270-47030 and assume it is the Toyota part number. It is not the part number and the housing may well be used across many years and models. The ebay ad you referenced made this mistake. Luck could be on your side but the odds are against it being the right part. The seller needs to reference the donor vin to be certain based on the year and trim. At that point he can list the proper Toyota part number.

So my second theory is you may have installed the wrong master cylinder/ecu/abs/etc. Plus the brake pump may be bad as well. Given there is a head gasket change already and a removed stroke simulator, there are plenty of variables in play.

I can't tell you for sure if these fundamental problems are involved with your car, but they may be. All these things have happened to others.

2010-2011 Master Cylinder Options. Notice these part numbers superseded an older part number. Which is another downside of a used part, it is likely the original flawed design.

 

C1368 means it did try to learn the valve offset, and the value it learned was out of specification. The repair manual is pretty terse on troubleshooting that: try initializing and relearning the offset again, and if that doesn't do it, change the master cylinder/actuator assembly.

 

Check the 12v battery is holding good charge (at least 12.2v ) while you are learning the Linear valve offset.
Also, make sure the parking brake is released.

 

It might also be possible to look in Techstream for the calibration number of your ABS/VSC/TRAC ECU firmware, and compare it to the versions for 2010-2011 Prius, say in the table on page 2 of T-SB-0363-10. That would at least probably tell you right away if you had an all-wrong version from some other car. Or if it was one of the 2010-11 versions, you would be able to see if it had already had the honk-reducing update applied.

If the firmware version is wrong, you miiiiiiight have the option of asking a dealer to reflash it to one of the versions for 2010-11. It's possible those assemblies are the same hardware and really differ by the firmware installed. But I don't know that, of course, and a dealer might just say that's crazy talk.

 

What calibration ID is shown for the ABS/VSC/TRAC ECU?

 

Ok, that's one of the original versions for a 2010-11 Prius with 15 inch wheels, according to T-SB-0363-10.

The honk-reducing update for those was F152647108.