RX_LX_IS Posted February 8, 2010 Share Posted February 8, 2010 2006 RX400h has a braking problem, where i have seen in other post happen when braking and the car hits a bump or pot hole, well i have seen the same problem when the RX400h is going down a hill (Auburn Washington has a lot of hills) when braking it starts to brake, then lets go. i learned about why this happens but now im working on a fix. I have herd of people having this brake problem before and herd of some people where their cars ended up rolling into the intersection and ended up being hit by cars. what I need to know is: When the brakes switch over, how does the car know when to switch, and how does the switching mechenism work? any info will help me What im doing: Im creating a controller to apply the brake presure to equal the same braking power as the electric motors during the inetial switch over of the cars. I have a few other question about diffent issues and problems with the RX400h and im creating some new devices and inventions so if you have knowlage about the RX400h, please view my other posts and help me out. Quote Link to comment Share on other sites More sharing options...
cduluk Posted February 9, 2010 Share Posted February 9, 2010 The solution to the problem is not that simple... There are two types of normal braking on the 400h- there's the normal disc brakes, and the regenerative braking system (which adjusts the transmission and other hidden components of the car). The brake pedal is just a switch that tells the computer how much braking the driver expects. The computer then tells the two devices how much energy from each to apply. The car uses several input devices to determine the ratio of stopping energies to be used based on the situation. The ratio is totally linear between the two, so it's not like the regen. is ON or OFF, but it is applied with different amounts controlled by the cars computer. If you're braking and you hit a bump, the car senses this (with the traction control and speed sensors), and lowers the amount of regenerative braking. Why? Because when you hit a bump, you lose traction, so no energy can be gained at that point. It's just the way the car's computer is wired. Also putting the car in NEUTRAL down a hill will prevent the regen. braking from working. At that point, you would only be using the normal brakes. One possible solution would be to record the signal from the traction control switches during normal braking, then wire a circuit to replicate this signal, and allow for this new circuit to be opened just before hitting a bump (so the car would have no idea you ever hit a bump). But unless you can predict when you're going to hit a bump, this won't really work. And if you were to wire this new circuit permanently, the car's computer will know something is wrong, and give you a traction control warning light while turning the system off completely... and this will cause problems with the traction control system itself, cause problems in snow, cause issues during an accident... really wouldn't wanna go there. It's just not possible without getting into the car's programming itself... Quote Link to comment Share on other sites More sharing options...
skyfish400h Posted February 9, 2010 Share Posted February 9, 2010 What I'm doing:I'm creating a controller to apply the brake presure to equal the same braking power as the electric motors during the inetial switch over of the cars. It would not be a good idea to modify the braking controller or rewire the actuators in any way. The regenerative braking is an integral part of the HSD and a safety concern... not just for you but for the innocent victim you may run into when your little mod develops a glitch. Why not wait until we see what the recall does to correct this braking behavior issue. In the meantime, just being aware of the behavior has allowed me to compensate in my driving technique. I have learned to brake earlier and more aggressively than I would normally think is called for, especially when doing down hill over rough terrain. It's much easier to retrain your habits than to unilaterally re-design one of the most complex automotive systems on the planet. I'm just sayin. Quote Link to comment Share on other sites More sharing options...
SW03ES Posted February 9, 2010 Share Posted February 9, 2010 But remember...he might be 16 but he's a "computer systems engineered" and money has no value to him... Quote Link to comment Share on other sites More sharing options...
lemon Posted February 9, 2010 Share Posted February 9, 2010 I have a few other question about diffent issues and problems with the RX400h and im creating some new devices and inventions so if you have knowlage about the RX400h, please view my other posts and help me out. Well, the flux capacitor could definitely use some tweaking. Also, the Mr. Fusion power plant has, as of late, been dropping in output. Don't know if it's the cold weather, or substandard trash I've been feeding it. Quote Link to comment Share on other sites More sharing options...
cduluk Posted February 9, 2010 Share Posted February 9, 2010 If you can find a way to hack into the car's CPU and edit code (without a port or proper equipment designed for the car) then i say go for it! I hope you know it isn't your average C++ type programming... Why don't you show us some of your previous work? Because as of right now you just sound a little... nuts. Quote Link to comment Share on other sites More sharing options...
kyo7878 Posted February 10, 2010 Share Posted February 10, 2010 ROFL.... Quote Link to comment Share on other sites More sharing options...
RX_LX_IS Posted February 11, 2010 Author Share Posted February 11, 2010 What I'm doing:I'm creating a controller to apply the brake presure to equal the same braking power as the electric motors during the inetial switch over of the cars. It would not be a good idea to modify the braking controller or rewire the actuators in any way. The regenerative braking is an integral part of the HSD and a safety concern... not just for you but for the innocent victim you may run into when your little mod develops a glitch. Why not wait until we see what the recall does to correct this braking behavior issue. In the meantime, just being aware of the behavior has allowed me to compensate in my driving technique. I have learned to brake earlier and more aggressively than I would normally think is called for, especially when doing down hill over rough terrain. It's much easier to retrain your habits than to unilaterally re-design one of the most complex automotive systems on the planet. I'm just sayin. Dont worry i just need some help in the design, i wont actually put the sysem on the rx400h for a LONG time. ill try our the system a FSAE car and a "hybrid" shifter kart im working on. i need a measurement or ratio for the force or braking power of the electic regenerative braking system. sorry if my grammers not good, im dislexic and have had alot of my grammer errors pointed out in my other posts Quote Link to comment Share on other sites More sharing options...
RX_LX_IS Posted February 11, 2010 Author Share Posted February 11, 2010 Why don't you show us some of your previous work? Because as of right now you just sound a little... nuts. I will post pics later of the LX470 i finished not to long ago Quote Link to comment Share on other sites More sharing options...
RX_LX_IS Posted February 11, 2010 Author Share Posted February 11, 2010 If you can find a way to hack into the car's CPU and edit code (without a port or proper equipment designed for the car) then i say go for it! I would just use a Super Toyota K+CAN commander Quote Link to comment Share on other sites More sharing options...
RXREY Posted February 11, 2010 Share Posted February 11, 2010 What I'm doing:I'm creating a controller to apply the brake presure to equal the same braking power as the electric motors during the inetial switch over of the cars. It would not be a good idea to modify the braking controller or rewire the actuators in any way. The regenerative braking is an integral part of the HSD and a safety concern... not just for you but for the innocent victim you may run into when your little mod develops a glitch. Why not wait until we see what the recall does to correct this braking behavior issue. In the meantime, just being aware of the behavior has allowed me to compensate in my driving technique. I have learned to brake earlier and more aggressively than I would normally think is called for, especially when doing down hill over rough terrain. It's much easier to retrain your habits than to unilaterally re-design one of the most complex automotive systems on the planet. I'm just sayin. Dont worry i just need some help in the design, i wont actually put the sysem on the rx400h for a LONG time. ill try our the system a FSAE car and a "hybrid" shifter kart im working on. i need a measurement or ratio for the force or braking power of the electic regenerative braking system. sorry if my grammers not good, im dislexic and have had alot of my grammer errors pointed out in my other posts Hopefully you aren't dyslexic when it comes to engineering! Ayayayeee! Make sure that you just keep working on the go-cart version and not the real Rx400h...please. By the way, dyslexic or not, don't you see all of the times when you write that the auto spellcheck is telling you something? Hmm? You do not make sense saying you are dyslexic, especially now when the computer will help you and give you the correct spelling of all of those underlined words,for Pete's sake.... Quote Link to comment Share on other sites More sharing options...
cduluk Posted February 11, 2010 Share Posted February 11, 2010 If you can find a way to hack into the car's CPU and edit code (without a port or proper equipment designed for the car) then i say go for it! I would just use a Super Toyota K+CAN commander ...and you think you will be able to read the code and make the necessary changes you want to? I HIGHLY doubt it will be easy to read or make these changes. Quote Link to comment Share on other sites More sharing options...
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