Unable to complete Linear Valve Offset after actuator replacement

Working on a 2008 Prius with 165k miles. The actuator in the car had a bad accumulator that would leak down and the pump would run every 15 seconds. I got a used actuator that was sold as tested from someone with excellent history of selling these. I've installed it, bled the car using a techstream twice, but i've found myself unable to complete the linear valve procedure. There is only a single code in the entire car, for C1345 not learning linear valve offet (and accompanying C1368 linear valve offset).

I've followed the factory steps by clearing the memory first, and the procedure goes through the motions - you can head the various valves and pistons making noise as the brakes are actuated. I don't believe there's air in the system. the pedal feels firm and will lock the tires up on a test drive.

The steering angle sensor is reading a bogus value (-1050 degrees or something similar) and doesnt respond to steering input. I have a suspicion that this is causing the linear valve offset calibration not to finish, as the ecu isnt capable of determining a baseline value for the steering angle, but trying to get someone's attention that may be knowledgeable to help me confirm before I throw parts at it.

 

Quick question though - the steering angle sensor should register a value when turning the steering wheel - and it doesnt in this case. It stays at -1050 at all times, regardless of steering wheel position. My confusion stems from the car not throwing a code for implausible angle sensor or bad reading. But, it appears that you work on toyotas for a living, and didnt know if the gen2 logic of the skid ecu throws a code for this condition or not, in your experience. No matter what, angle sensor isnt ever changing both on my techstream and Autel scanner.

I am assuming for this calibration procedure to complete successfully, that a functional angle sensor is required at the very least before i write off the actuator as bad?

 

the gen 2 manual i have access to also says that the steering wheel must be centered as a condition. I will check wiring between angle sensor and wherever it goes to before replacing real quick, i guess. I appreciate the time you took to answer. I have a gen 3 on hand that does respond (as every normal car does when you turn the wheel with a working sensor)...I've found your answers while googling to be well informed and its probably about as good as im going to get. This seems obvious, but the car's been a basket case prior to getting to me from all kinds of hacks, but generally the computers are excellent at throwing errors when appropriate (for example, due to out of range or implausible reading) so i figured id ask someone that may have more specific knowledge

ill try going for a 22mph+ drive to see if the computer starts displaying sensor data. How finicky are those linear valves if the pump is good and the accumulator holds pressure? this this the second time i do this job on this car and i was really hoping this actuator would be good. Its a car i own (customer car would only get new). Initial actuator as it came couldnt hold pressure, second one - used - had a bad pump and couldn't build pressure, this one seems to be acting normal in all ways besides the linear valve unable to calibrate.

 

Any idea about the steering angle sensor in particular in this case

 

Yes, I do. I'm using a heavy duty battery maintainer/charger at my shop that is able to keep a solid 13v+ throughout the procedure. Im not real familiar with this type of braking system but work on cars all day every day. Do you know if the linear valve calibration requires a functional angle sensor reading? The procedure requires a reset of the yaw + angle sensor values before starting.

 

I hear you...I believe those are all replacement units, too, in that the part number was changed after the car's production run were done. I couldnt find one when i was shopping for these units (44500-47141).

 

Thanks for the info. will change search parameters to this new part number. Just curious if you have any insight into that angle sensor. This car is new to me. purchased as a non runner with lots of deferred maintenance and issues, and there wasnt a code stored initially for the angle sensor, but it is definitely not showing any data in the live data

 

Thanks. You were right about the angle sensor off value being a red herring. I took it out for a drive above the calibration threshold for the required amount of time and the skid ecu started reading the angle sensor properly, so I think i just have a plain bad actuator :-/

 

Well, im really pulling my hair out. I got a super clean unit with updated part number (44510-47051) and still running into linear calibration issue. The car was bled using the procedure with techstream. Im at wit's end. Is there a way to find out what is causing the failures? I can't really throw in the towel, but i suppose i might be getting a new actuator for the 4th attempt.