I have read several sources that say the Prius recall (or SSC) will involve updating braking software for the 2010 Prius. As I have never had this done on my 2005 Prius, I'm wondering how complicated and how long this might take. Is there a danger in "flashing" the brake ECU? I guess I'm somewhat concerned that if the "fix" is installed/downloaded improperly that the car could be severely impacted and not work correctly. Anybody with experience on this?
There have been several firmware updates for the gen2 (2004-2009) over t he years. My 2004 ecu's have been updated 3 times, but not since mid 2005 so your Prius probably has those updates already. The process takes a while and the procedure requires that the 12v battery be put on a charger to make certain that the power is not lost during the flash. Several early Prii were temporarily disabled (the ecu being flashed needs to be replaced if this happens) when poorly trained technicians didn't follow the procedure, but by now they have all learned the error of their ways (the dealer had to swallow the costs). As far as I know Toyota has not prepared/tested an update for our Prii to minimize the regenerative braking dropout. The "Fix" is only being distributed for the Gen3 (2010) at this time. I expect Toyota to offer it to us at a later date, but it may not be free for those of us that are out of the warranty period (My 2004 is almost 6 years old and has 168,500 miles). As others have noted there is NOT a loss of brakes when this occurs. Just press harder on the pedal and the friction brakes will engage. The sub-second delay in stopping will not cause an accident as long as you were leaving sufficient braking spacing between you and the obstacles in front of you. JeffD
The only other danger from a reflash, other than those mentioned above, involves the new firmware. Obviously, any time you change a program you can introduce new bugs or reload old bugs (regression errors). We can only assume that Toyota will do a thorough job engineering and testing the new braking code. Tom
This is another thing that concerns me. I will assume the Toyota Service Technicians know how to do this properly on our 2010 G3's (I mean, I hope they do) but am a little concerned that the "fix" might cause more problems than the braking "issue" (which for me personally, is a non-issue). I'm thinking I may hold off awhile on this to see what others have to say about the "fix." Of course, this is all assuming that's what Toyota announces sometime this week (we really don't know yet).
Toyota EU says the pocedure should take about 40 min dealership visit. The dealership will use their standard programming equipment (Techstream probably).
The actual flash-update process and verification (if any) might take a minute or two. Connecting the TechStream to the CAN buss, operating, and the disconnect might take a minute or two. Paperwork and moving the car around, maybe 20 or 30 minutes. Waiting for them to get around to your car ... maybe 2 hours? As with all "service", the "installation" needs to be done competently.
The firmware download takes less than 3 min to put into the abs ecu from techstream. Did 6 cars today, one with a very repeateable nature. All 6 were taken for a test/drive cycle on rough roads in the local area and across rail crossing where the fault is known to be reproduced at will.once reflashed,none of the vehicles showed the fault.
That's not quite true. Now days enough ECU flashes have been done by the techs that the risk is negligible, but there were a handful of ECUs fried in the early days of the 2G Prius when proper procedural steps were not followed. IIRC, the 12v battery has to be hooked up to a charger, the car left in IG-ON mode during the flash and if anything disconnects, shuts down, whatever it's possible to permanantly damage the ECU and then would require replacement. But I haven't seen a single report of that happening in at least 4 years, I think they've got the process down pat and the risk is minimal. Obviously, if something did happen it would be on Toyota to replace the ECU and provide you alternate transportation during the delay. And that, IMO, is the biggest benefit of having Toyota do the procedure rather than allowing the end user to do it as proposed in another thread. If YOU fry your own ECU b/c you mucked up the procedure then you get to eat the $2000 for the replacement!
In the engineering world we refer to this as "bricking" a device. In other words, you take your nice electronic device and turn it into a brick doorstop. Flash updating requires the device to be alive and have functioning communication and flash programming firmware. If you trash the flash programmer during a flash update, there is no way to recover, other than sending the device back to the factory. Tom
Some ECUs and devices allow recovery from a failed flash by use of a hardware bootloader. (The iPhone, for instance.) The device can automatically go into this mode when hardware detects a bad or missing flash, or you may have to do something to do it. Subaru ECUs (I think it's that brand) allow you to recover from a failed flash but you have to open up the ECU and solder some wires on it. A bit complicated, but better than having a totally bricked device. I have no idea if the Denso ECU's have any of these features ... and may need to be sent back to a repair facility with the proper gear to re-flash the EEPROM in place.
Autocar magazine in the UK have just had the Prius III brake ECU updated: Toyota Prius recall - our car is the first in the UK to be fixed - Our cars Only took 2 minutes!
Earlier this week, I and one other tech paired up to perform 50 ABS reflashes on in stock Gen 3 Prii in less than 7 hours including finding and getting the cars and returning them. The actual reflash procedure takes less than 10 minutes.
... and I thought it was called "smoke testing." You know, plug it it in and replace whatever smokes.
Similar. Smoke testing releases the "magic smoke" necessary for the operation of all electronics. This is why electronic devices no longer work after the smoke gets out. With bricking, the electronics are usually still good, but the device has entered a state from which it can't recover. Tom
