brake, abs and vsc lights came on while bleeding brakes and electric booster stopped working

per other thread i have been replacing small brake lines in rear of car and checking discs. didn't seem to have much air, never let the reservoir go empty although I did unhook the disks to back them out. so i still had brakes but they were low. i was getting brakes to all wheels. and I got air from fronts. good pressure, could hear the electric booster go when the peddle got hit. then my wife who was pushing the peddle said all the brake lights came on and suddenly i got no booster, brakes in the front and none in the back.

i don't know if i shouldn't have had the car on or Wth. now the front brakes are solid as a rock but no boost and all warning lights are on. OBD readers both hardwire and bluetooth see no codes and nothing wrong. "Car Scanner" software for the vlink knows its looking at a 2nd gen prius and sees no problems.

i see various videos about jumping the OBD with a paper clip to enter diagnostic mode and clear codes once the fault is corrected, but i don't know what the fault was, or if that will restart the booster and ABS stuff or . . . .????? It would have been registering 0 miles and hour so i don't think that the wheels not spinning could have trigger the ABS. Not sure how to find out what set the warning lights and if it prophylactically depowered/deboosted the brakes and no clue why the back brakes seem essentially isolated. I don't know if it has pressure sensors downstream of individual lines so if it sees differentials it presumes the rear lines were leaking and cuts them off. that would be really clever but it doesn't explain why the booster is off or if that senses air and shuts itself off and i have to figure out how to reset it.

lost in exeter.

thanks

 

@ChapmanF

Right. Is there a good thread on how to extract info from diagnosis mode? I'll go searching but if there is a favorite or sticky . . . . thanks

Meanwhile I found a thread that suggests the brakes are in failsafe mode which cuts off the rear brakes and applies only the front directly from the master cylinder. It shows, as i suspected, that there are pressure sensors for each wheel and i suspect that one showed low. there is apparently a way to disable all this crap while bleeding so that doesn't happen but of course i'm late to the party and it's some kind of need to know basis. I saw it mentioned, but not how to do it.

I've done a bunch of peripheral brake work on gen 2 and gen 3 and never had this problem before, but maybe I have just been lucky that it never triggered a wheel cylinder pressure sensor before even though i had a little air at the caliper ends, probably not enough that there wasn't some pressure in the line.

it looks like there are a bunch of generic handheld OBD coupled units that are made to address electronic brake controls although the prius always seems to go off the end of the charts in terms. I'm sure that there is a techstream version as well. Everything goes back to techstream and i've just never bit the bullet and got that going in other the offical of unoffical versions. There is always a time when you cross that threshold although hoping diagnosis mode might be able to pull this out of failsafe, but who knows . . .

 

@mr_guy_mann

thanks, i'll go look for that sticky.

the threads i've seen show diagnosis mode coming up on the screen on the prius vs. a flashing led that tolls codes. where is this flashing light to count. and maybe the technical discussion has a list of codes and how to clear them so I can see if it resets or a code. thanks for any direction. and/or i'm off to google.

 

@mr_guy_mann
@ChapmanF

ok, the paper clip adventure worked. couldn't figure where the blinking lights were or if each warning light that was blinking should be counted or . . . and I've seen several threads that say if the problem is a brake problem, pump the brakes once you power up in diagnositic mode, one thread said 7 times, one said 30 times, i just pumped for a while, pulled the paper clip and all was well.

why or why is it with these cars you have to do all this crazy non-intuitive stuff. i get that they are complicated and computer driven but why isn't there a bluetooth dongle that can read the brake codes and/or reset those brake diagnostics, etc, or a button that makes the onboard console into a diagnostic for all OBD issues. Maybe if you want answers on fixes you have to buy something extra. I honestly wouldn't object to a legitmate purchase of tech stream if it wasn't an annual hit. I have one style car, am fine with older versions. Instead they are like microsoft wanting you to reup every year. They need a model that sells the service by model. If you're a repair shop, you probalby see all models and you buy the master license but if you own one car you buy for that car. I'm starting to see something is the right to service movement. There just is no reason for this stuff to be obscure. And if someone tries to cricumvent a code without fixing something, then the code will just reset so it giving access to this management seems like miinimal ability to actually run these cars day to day. That's an old saw I would imagine so i'll stop whining, its unbecoming.

Still interested in how you could turn off the monitoring functions during brake bleeding. in my case I wasn't trying to bleed the master, or pump or accumulator. I had made sure not to get any air in the top of the system. i was just bleeding peripherals and I think this probldm could have been avoided if I just could have had the sensors stand down during bleeding.

thanks again for responses to date.

brian

 

patience is a virtue. i can see i'm covering ground that has been covered and I appreciate that.

i've got the Vlink dongle and three of the apps mentioned (although @mr_guy_mann doesn't seem to say that any of them can retrieve model specific brake codes). dr. prius and torque pro don't want to talk to the dongle although they did once upon a time. "car scanner" syncs and it allows selection of vehicle type which i would hope might access vehicle specific codes of this sort, but no dice. and there similarly doesn't appear to be any way to use these dongles/programs to alert the brake system to bleeding.

And, of course, with brake, ABS and traction control lights all being lit from this one circumstance do they all blink the same code?

I suspect ECB invalid mode is what i'm after. Don't know if that disables the actuator altogether or just the sensors so you still have power to bleed with.

i found a thread for this on the gen 3, where @Mendel Leisk posted the instructions for selecting ECB invalid mode on that gen. not sure how close the instructions for gen 2 are to gen 3.

I agree with you that 2 day subscriptions are reasonable but I have a dozen cars and when one is laid up for work i'm driving another so I tend to start something and then come back a few days later to finish it, so trying to calculate which 2 days i'm going to need access to manauls and/or tech stream is difficult. appreciate the snippets and experience posted.

thanks

brian

 

@ChapmanF @Mendel Leisk @mr_guy_mann so many searches have turned up manual instructions that explain how to set ECB invalid mode without techstream for a 2010 i (courtesy I think of a manual snippet posted by Mendel):

(b) Select ECB (Electronically Controlled Brake system) Invalid Mode.

(1) Perform the procedure listed below in 1 minute.
1.Turn the power switch on (IG) with park (P) selected and parking brake applied.
2.Select N and then depress the brake pedal more than 8 times in 5 seconds.
3.Push the P position switch and then depress the brake pedal more than 8 times in 5 seconds.
4.Select N and then depress the brake pedal more than 8 times in 5 seconds.
5.Push the P position switch.

(2) Check that the brake warning light / yellow is blinking.

would that rubric work on a gen 2? or is there another list of buttons to push while singing the star spangled banner backwards in japanese ? the macro instructions to that portion are a little unclear because they seem to say even with techstream or invalidated ECB you might set codes so I'm maybe back to the same problem in the end of clearing the codes.

At this juncture I have a new brake line 4732347030 (per the help I got on this thread, thank you, and only $7 from toyota dealer plus $11 shipping although they had a service fee to pick it up at the dealer so it was about the same either way) and a rock auto rear wheel cylinder because the bleeder galled on the existing. So now I need to get into the brake system again and bleed again although not up at the ABS or actuator area.

 

thanks for quick reply. maybe i'll try with the 12V battery disconnected. that might be another way to get ECB invalid without setting codes . . . brian