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

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Owais Siddiqui, Aug 3, 2021.

  1. Owais Siddiqui

    Owais Siddiqui New Member

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    The trial and error replacement of ABS actuator didn't work like anything ever in the past for me unless the codes and other diagnostics are reasonably definite. I still have the same three codes C1203, C1345, C1392.
    During the air bleeding process, the four wheels bled fine but when I bled air from the stroke simulator, it didn't spit out any brake fluid and I tried it multiple times. So the bleeding failed every time I tried at this stage. I wonder if the cylinder is blocked and if this has anything to do with the codes. I have no idea.
    The linear solenoid offset failed like before i.e. no flashing of ABS/VSC/TRAC/BRAKE lights on the dash during the process at all. I don't know if I should continue shooting arrows in the dark like this or try replacing the pump/actuator assembly now. I am totally lost now.
     
  2. Owais Siddiqui

    Owais Siddiqui New Member

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    I think now I have some clue for the first time although its still vague. Here is my theory, my engine rattling was related to the regenerative braking and it made my weak head gasket case further worse to a point where it just started throwing white cloud like smoke. I replaced the head gasket but the reason of rattling is still there. Although sitting idle the engine runs fine but I do hear very little rattling once in a while especially yesterday when I was doing the brake air bleeding which failed every time I tried doing it. No brake fluid coming out of stroke simulator during purging/bleeding is another sign that my regen braking has some issues and not my ABS or the regular hydraulic braking. I have no clue as to where to start, how to make sure or attempt fixing the regen problem. I don't think I am ready to do anything on the transmission right now.
     
  3. ChapmanF

    ChapmanF Senior Member

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    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.
     
  4. Owais Siddiqui

    Owais Siddiqui New Member

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    I am still concerned about the occasional and very brief rattling which to me has something to do with the regenerative braking and I just hope that fixing the ABS codes without any major work on the transmission could solve the problem.
    Since I've already replaced the ABS actuator, I assume the pressure sensors, linear and isolation valves inside the unit are functioning fine than the problem will be local to the stroke simulator itself. Could that effect the front axle brake sharing or may be "brake fighting" (hence rattling) between the hydraulic and the regen brakes that I am not sure about. I wish if I had some sort of schematics or cause and effect to go through and start some logical diagnostics and avoid guess work.
     
  5. ChapmanF

    ChapmanF Senior Member

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    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.
     
  6. Owais Siddiqui

    Owais Siddiqui New Member

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    I think the simulator sits on a bracket and is available separately and I've not replaced it or fixed mine.
    I don't know much about Prius regen system but based on the communication and other enhanced codes I was thinking about the power management local fault, its communication fault with the brake controller or any local fault with the motor/generator in the transmission which might cause unintended braking (might also depend on hydraulic brake status) that could cause engine rattle at high torque demand.
     
  7. ChapmanF

    ChapmanF Senior Member

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    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.

    [​IMG]

    ... 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.
     
  8. Owais Siddiqui

    Owais Siddiqui New Member

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    Well, look at the black bracket the simulator is attached to the assembly with and look at the eBay item number: 393066493690 and for more views of the simulator eBay item number: 232400263117. I only replaced the electro-hydraulic actuator of the assembly.
     
  9. ChapmanF

    ChapmanF Senior Member

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

    [​IMG]

    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?
     
  10. Owais Siddiqui

    Owais Siddiqui New Member

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    I figured that I wasn't carefully following the steps for air bleeding, memory reset and linear solenoid valve offset functions. Long story short, I was able to do the linear solenoid valve offset but it doesn't finish successfully. The procedure takes 120 seconds (2 minutes) with multiple cycles of ABS pump on/off. It starts normally with ABS/VSC/TRAC lights quickly flashing. Suddenly at 100th second something happens and the lights stay solid, quit flashing and the pump stops too. It does continue doing the procedure till 120sec but doesn't change anything i.e. the ABS/VSC/TRAC lights stay solid after the procedure too.
    The codes I am getting now are C1345 and C1368 which means the C1203 is now out of the way and both the codes C1345 and C1368 are related to linear solenoid valve offset. The occasional engine rattle does still bother me but I am focused on resolving the ABS/linear solenoid valve offset issue first.
     
  11. rjparker

    rjparker Tu Humilde Sirviente

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    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.

    AB07FAD1-D6A8-472F-9321-8980E95DDCC8.jpeg
     
    #31 rjparker, Aug 22, 2021
    Last edited: Aug 22, 2021
  12. ChapmanF

    ChapmanF Senior Member

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    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.
     
  13. smokeGTI

    smokeGTI Member

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    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.
     
  14. ChapmanF

    ChapmanF Senior Member

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    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.
     
  15. Owais Siddiqui

    Owais Siddiqui New Member

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    Thanks and I appreciate your detailed assessment in my case. The engine rattle is secondary for me because I am not sure if it is really qualified to be called a rattle. Its rattle type (since I heard the real rattle for a long time on this car) mechanical noise that hardly sustain for less than a minute and once in a while. Once I fix the ABS problem, I'll address it at that time.
    As for the two, pump and actuator assemblies, what I replaced so far was carefully purchased for the same year 2010 and so chances of wrong part is almost nill but there's no telling if the replacement itself was bad. The ebay listing # I posted were for reference only not to show what I actually purchased/replaced.
    If there's any internal leakage in the pump diaphragm/assembly, I would assume that the brake ECU will register fault code C1256 for low brake fluid pressure. In my case I don't see any such problem i.e. no fault codes or no abnormally long/short/intermittent run/stop pattern/cycle for the brake pump so far. I wonder if there's any way to tell that the brake pump assembly needs to replace the brake pump assembly.
     
  16. ChapmanF

    ChapmanF Senior Member

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    What calibration ID is shown for the ABS/VSC/TRAC ECU?
     
  17. Owais Siddiqui

    Owais Siddiqui New Member

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    That's what I plan on doing. I repeated the learning procedure multiple times already but I am going to retry again carefully and keep replacement of the actuator assembly as a last resort. I do not have the TSB but I'll share the cal ID here too. Thanks a lot for your patience all along.
     
  18. Owais Siddiqui

    Owais Siddiqui New Member

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    I repeated the linear solenoid valve offset learning multiple times and it keeps quitting every time but this time it quits after 40sec. The Calibration IDs are Engine and ECT; 34715700, A4701000 (calibration update; "NO" for both) and for ABS/VSC/TRAC; F152647106 (calibration update; YES).
     
  19. ChapmanF

    ChapmanF Senior Member

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    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.
     
  20. Owais Siddiqui

    Owais Siddiqui New Member

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    As I mentioned earlier that the brake actuator (not the whole assembly) was replaced and the stroke simulator that was replaced still doesn't discharge any brake fluid during the bleeding procedure as was the case originally. I think I am pretty much at the same stage where I was before replacing or doing anything on ABS. Yesterday when I started the engine I noticed the rattle for little longer may be upto a second and I can tell this was the same engine rattle I used to have before I replaced the head gasket. With all of this being said, I am not really convinced that I am going in the right direction. Since the codes so far are not direct or pointing to any specific component or subsystem malfunction I tend to think that it is not directly ABS pump or actuator assembly related problem. I may be wrong but I have a feeling that after replacing one or both of the pump/actuator assemblies once again I'll still be failing the linear solenoid valve recal because the problem may be something else and I am just guessing that it is the ABS actuator which is failing the linear valve recal. I wish if any TSB or manual would elaborate on the reasons why a linear solenoid valve calibrations could fail.