Hello! I am an engineer who builds racing systems for go-fasts and programs aftermarket engine controllers on the weekends. My day job is designing hard drives. I bought my '05 Prius with 32K miles two months ago and couldn't be happier!! (I have averaged 53 mpg on 3 tanksful in the Colorado winter.) What I LOVE about the Prius, it's such a break-out car, unlike anything else out there! Very "high-tech", I dig it! From the PWM inverter to the modified Atkinson cycle engine, it's all so neat! Speaking completely frankly, the mileage is a nice, thick layer of icing on the already yummy cake! After buying the factory manuals and My big question is what scan tool I need to do somewhat basic maintenance. For example, changing the coolant. (Yes, I know, I don't have to do it, but I usually take VERY good care of my cars.) Firing the pump to burp the system is quite easy, simply energize the relay coil. However, that bypass valve uses a PWM signal in closed-loop with a position sensor! There's no way I can replicate that. So what scan tool out there does both OBD2 scanning as well as issues commands like this, "Diagnostic mode", brake valve opening commands, and the like?? Thank you in advance for any time you can spare me! -Damon
Hi Damon, welcome to PriusChat! :welcome: You have pinpointed the reason there are no shade tree Prius mechanics. The Toyota scan tool recognizes some private codes and can issue commands, but it costs a few thou. I hope someone chimes in and proves me wrong!
There most certainly are shadetree Prius mechanics, and the line between "pro" and "shadetree" capability has been getting fuzzier all the time. Cheaper scantool option is Autoenginuity with the enhanced Toyota add-on, which includes a fair amount of prius-specific bi-directional control now. I haven't specifically tried spinning the coolant valve around but I assume that it would work. I've got their version 5.0 or 5.1, I think they're a little beyond that by now as the current release. . If we're talking engine coolant, make sure to open the air bleed under the driver's side of the top radiator support too [a small hole with an Allen fitting underneath]; apparently that's one important part that some people miss and then they have lots of trouble purging the air. . _H*
Wow, thanks for the responses! I see a few things about coolant here: Toyota Engine Module List I found this entry: Pump Check Pattern ActivationDrain System Air Bleeding Pattern Activation The price tag for unit + Toyota add-on seems reasonable given what it must take to develop this system and how many they probably sell. Thank you, Hobbit!! As for the burping procedure, I was going to follow the Toyota method published on toytech. I did see there is a burp valve to open near the coolant bottle, IIRC.
