remote start

How about radio control, so you could send your Prius to work even if you were home sick......

 

I had a look at the Japanese site and one of the sponsors pages take you to a site in the US that manufactures miniature RF tranceivers so the logic is
1) the fob and the SKS system are short range transceivers
2) we need to extend the range
3) we need to receive from the car immobilzer the encrypted signal and transmit the fob signal back to the immobizer
4) the remote ignition on signal has to power the brake lights to tell the immobizer that it's got the brake on
5) the remote starter has to close the circuit for the Power button
so now the problem becomes how to get the immobilzer signal to the RF transmitter with out it being powered all the time thereby draining the 12 volt aux battery. Granted most of these devices are low current draw so that might not be a problem. Some electrical engineer types are bound to figure it out. It's not impossible but not a simple one either.

 

Frank,
What you describe above constitutes "fully" starting the car. If the car were started this way, anyone could walk up to the car and drive away.

But the remote start on 2 different cars that I owned in the past would shut off the engine if you did anything inside the car without putting the key in. Thus, the car was NOT in the fully started condition. Only the engine was running. Any attempt at that point to drive it would disable the car.

Thus, I don't think remote start would work that way. Toyota would have to have built into the Prius somehow a way to accommodate a signal to start the engine, but to NOT put the car into a fully ready condition. Thus, the various "codes" would have to have been made temporarily irrelevant. And then only if you approach the car with the SKS in your pocket would the car go into the fully operable condition. So only then would the RF "codes" become relevant.

In any case, there is only one way to find out. I just called my dealer and found out it only costs $350 to install it. Although he at first was SURE it would work on the Prius, after I asked a number of questions, mostly about the SKS, he was not so sure. So he is going to see if they have done it before and if not he is going to call the company that makes the device to see if they have done it before.

He said he will get back to me later today. I had decided originally to not get the remote start due to the waste of gas, but at $350, I think I just might get it after all. It was pretty cold here this morning. Plus "wasting" gas is all relative when it comes to the Prius.

I'll post here when I get the word. But even if I get the word, I'll be a bit suspect. For example, if the remote start somehow removes my cars SKS ability, then I don't want it.

 

Thanks for the responses, and please keep updating because I also have received so many conflicting opinions from both Dealers and installers of remote devices, This may not be important to warm weather people, but we here in the Northeast have a lot more at stake.

 

My dealer just called me back. He says it is not possible to put a remote starter on the Prius.

He said he called the company that supplies the devices they use, and he called his home dealership office.

(My local dealership was bought out last August by a larger dealer.)

So it looks like the solution would be along the lines described by Frank above. And that solution cannot possibly be cheap.

 

good point on the car being fully ready to go. But the ICE will not run unless the car goes to "ready" so put a relay across the interior light, so if it comes on the relay closes and the ICE stops. Add another relay across the seat switch and same thing. Now comes the hard part of this electrical engineering problem tie in the SKS so if it's within close range the two relays are redundant. How are we doing so far? Not cheap and probably do able. Come on you EE's lets get on this! There is a market growing day by day. And more makes and model's to come.

 

It might be possible for a remote start device to share in the transponder/hybrid ECU communications. If I recall the immobilizer description, the communications between the two are encrypted. If it is static shared secret, then another box could mimic the transponder and start the car. That might be how the Japanese box works.
One thing I have read, if one of those ECUs (not sure if it's one or the other, or either) is replaced, then it must be configured to sync with the other upon install.

One would think that if it were that simple, then the car would not be secure, but then in order for a box to learn the codes needed, the fob probably is needed to set it up.

 

Hey Dan, interesting thinking about this. Someone will crack it but it's not going to be easy.

 

Why is everyone thinking you have to use the factory fob? All that is needed is a transponder bypass kit for a prius. But no one makes it yet I'm sure that there will be one out sometime we just have to wait for demand and or other toyota cars using the same system. Its not rocket science just about every GM vehicle made since 2000 have transponders in the key. Ford,Dodge,Jeep,Toyota all use transponders in some models. The bypass kit has a loop of wire that goes around the key switch and sends out the transponder code when the remote start is engaged. In the Prius this loop would go around the back of keyfob socket and send the out the learned fob code. Once this kit is out installing a remote start on a prius would be a 30 min install because there is really nothing to interface but the power button,brake switch and hood pin switch.

 

A: why would we need to interface to the hood pin switch? We aren't opening the hood. Perhaps the door switch, or better the dome lights, so the car can be shut down if the doors are open?

B: How would you know what code to send through that loop?

 

I thought the SKS system used a rolling code?

 

The hood pin is to disable the sysem if your car is in the shop being worked on so the remotestart system does not activate and the brake switch will kill the system to.

The SKS might be rolling code but when your stick the fob in the socket its passive the code is the same everytime your BCM learned this code. The bypass module learns this code too and sends it out when the remote start is active. I might try a few kits when I get some time and see if I can trick the BCM with them or if we will have to wait on one made for the new toyota sysem.

 

Nope, not how rolling code works. Rolling code sends a different code each time, that's what's so secure about it. The transmitter knows what code it should send next for the receiver to accept it, because they use the same algorithm to determine the next code. If the receiver misses a code, it will check to see if the code the transmitter sent matches one of the next 255 codes the receiver would expect to get from the last valid code it received.

The remote starter has to know that algorithm. I suppose you could use a genuine fob as part of the remote start, but that could give a thief an opportunity hijack it out of the remote start. You'd want to be really sure that remote start is secure and well hidden.


If you have the right chipset for the rolling code algorithm the prius uses, I suppose you could program the prius to accept its output as if it were an additional fob but you couuld not mimic an existing fob. This is how homelink works for garage door openers with rolling code. Once the universal homelink is programmed to know your remote's frequency and rolling code algorithm, then you have to have your garage door opener programmed to accept the universal homelink as valid.

Remember, on the Prius, the brake switch has to be pressed to go into ready mode. That's why I didn't question that connection.

 

Its not rolling code on the passive part its only rolling on the SKS. Because its not powered its a passive rid system not an active. There are 2 different systems in the fob. The passive is backup incase the battery goes dead.
I clone rolling code security remotes all of the time its no big deal. Do you have home link? and cloned your garage door chances are its rolling code too. Also the brake is not big deal you set the remote start for diesel mode and use the glow plug output to "press the brake" then you use the start wire to "press the start" very simple install because the prius starts itself not the remote start unit so you dont have to worry about tach wires and acc and ign hookup.

 

put it together in a box and sell it. you've got an audience here.

 

While the published procedures include a foot on the brake for starting, one question does arise in my mind, does the system check for the driver to be seated? this is not a step that would be published, but it might exist.

An open window, closed door and broomstick would find that out pretty quick.

 

I've jumped start other cars many times. I just open the door on my prius stick my foot on the brake and press power, it goes into ready, I don't need to be in the driver's seat.

 

Hmm. I can only find rolling code mentioned for the wireless remote function for locking and unlocking the doors with the fob. No mention of it even for SKS, so I hope it is there. Toyota may have found it only necessary for remote, as SKS is short range (within 5 feet) and the passive mode by putting the fob is really short range (1 inch?).