Adding smartkey door handle (rear or pass side)

i have been following this thread as i would like to do this mod as well. i have found a diagram for the genII prius sks. i'm not sure if it will help, but i have attached it for anyone's reference

 

I wouldn't call it cheap so much as trying to force their Prius customers into a much more expensive car. In 2008 and 2009 SKS was basically on every Prius sold except the few ones with no option package. The price above rock bottom was only $575 for SKS and several other nice features. A very reasonable deal indeed which I'm sure generated lots of sales. I wouldn't have bought my 2008 without 3door SKS. Then in 2010 Toyota bundled 3 door SKS with package 4 and 5 with a cost in the thousands over even package 3. No separate 3 door option offered at any price on package 1, 2 or 3.

I hope the efforts on this thread end up making 3 door SKS practical for all that wish they had it.

 

I think that's very likely. I'm kind of on hold right now until the parts I ordered get here, but I wound up spending a couple of bucks under $300 on parts. That, plus a bit of wire and some connectors, then some time to install and wire everything should be all that's needed.

Once I get my parts I'll post a nice how-to guide here, but even at this point I'm 99% certain that this is doable and affordable.

 

this is a wonderful effort, thank you everybody! the difference in price from a II to a IV is not worth it if all you want is 3 door sks, but i would definately miss the hatch, i use it all the time to lock the car. it's easier to see the lights blink. i can't always tell from the drivers door.

 

Keep in mind, if you lost a little range with one antenna in parallel, you might lose a LOT of range with 2 extra antennas! It's even possible that you could fry the MOSFET that drives the 134khz signal inside the certification ECU.

I would want to analyze the drive circuit inside the cert ECU before advising anyone to blindly start adding antennas. Adding antennas in series would at least be safe for the drive circuitry. In fact, if you add 3 antennas in a series-parallel configuration, you would keep the original impedance.

I do not recommend anyone perform this mod until we know for sure the specs of the drive circuitry inside the cert ECU, unless you are ok replacing it.

 

Thanks for the reply, pEEf, and it's definitely good to have an EE on board here because, while I understand the concept behind what you are saying here the practical application is way over my head.

I'm still hoping to get that certification ECU out to take some pictures for you, but life has been a bit hectic lately. As soon as I get a chance I'll post some pictures... hopefully this evening or tomorrow evening.

Thanks again for your help with this project,
Brett

 

OK... I finally managed to get it out of there and got some pictures for you. I've attached them here, but I have higher resolution ones that I could email you if you want... they were just too big to post with this message.

Also, the computer is still out of the car if you want close up's of any part or labels off of any chips or anything, but I'll need to put it back to drive home in about 2 hours... so hopefully you can catch me with any requests before then. But if not I've finally figured out an easy way to get it out, so it won't be a problem to pull out again.

Thanks again,
Brett

 

So looks like they have left out a lot of parts, namely I see a bunch of 1/2w looking SMD resistors. not populated I would assume that there is also a different software load, but I suppose it could simply be the lack of resistors. It's at least worth checking!

The antenna drive waveform looks like it's generated from the the middle LSI which is typical of Denso. Without bench analysis I can't say for sure if a substantially lower impedance antenna circuit will do harm to this or not. Without knowing more, I'd say test the series antenna configuration, as it's unlikely a higher impedance could harm it.

 

I probably won't do too much more playing until I get my parts, but hopefully that will be soon. The last update said that the warehouse had to order the parts since they didn't have them in stock, but they only anticipated a delay of a few days. I'm hoping I get them later this week or early next week at the latest.

However, once I get the parts I'll try to connect the antennas in series and see how that goes. What's the effect of changing the impedance on the range? Is increasing the impedance going to lower the effective range the way it did when I had them connected in parallel?

Also, what about connecting two antennas in parallel, then the third one in series with that pair. In my (very limited) understanding that should still wind up with a higher impedance, but much closer to stock than connecting three in series would be.

Thanks again for your help with this. I have no problem doing the mechanical stuff and connecting wires together, but most of what we've been talking about here is above my head and it's definitely helpful to have someone who understands it.

Brett

 

It would be very interesting to compare this with the certification ECU from a car with 3 door SKS.

Peter (or anyone else with a gen III with 3 door SKS) do you feel like pulling out your ECU and taking a couple of pictures for us? It's an increadibly easy thing to do... should take less than 10 minutes, including the time you spend taking the pictures and doesn't require any tools.

To do it, first remove the lower glove box... directions are in the manual because you need to remove it to access the passenger compartment air filter, but basically you open the box, unclip the damper on the right side, lift the box up to disengage the hinges, then pull it out.

Once the box is out you'll see the certification ECU behind it. In my car it's the only one with a blue case, as you can see in the picture below. Once you've identified it, disconnect the two cables going to it (the ones circled in red), then unclip the two black clips on the front of the case... one of which I circled in yellow, and there is a matching one in the same spot on the bottom of the case. After it's unclipped the black front piece comes off, then you can grab the connector and pull the ECU circuit board out. You'll need to pull it straight out most of the way, then push the front toward the left or it won't clear the frame for the glove box.

Once it's out take two clear pictures of the front and back, then do the reverse to put it back together.

I did this with the car off and the battery still connected without any problems... in fact, all of the testing I've been doing I've done with the battery still connected and I've connected and disconnected this ECU a number of times during my testing without any side effects, but if you want to be abundently careful you could disconnect the battery ground before you do this.

Do note that the SKS system as well as the lock and unlock buttons on the remote won't work when you have the ECU disconnected. I also imagine that the car won't start with it disconnected, but I've never tried to start it that way.

Thanks in advance,
Brett

 

It's hard to say without more information, which is why I want you to test it. Series is safer, as it's less drive current.

My guess is without a 4th antenna to balance the sides, you are going to see abysmal range on the 2 in parallel and near-normal range on the lone one on the other side of the series circuit.

 

You will see all those missing 1/2w resistors populated along with a few other small parts. This isn't going to tell you if the firmware is different however, so the only way to check is to perform a test.

I did a bunch of analysis on a 2011 with 1-zone SKS last week for another project, but unfortunately I didn't have access to the car long enough to mess with the SKS. Next time I get access to a Gen III, hopefully I can get the scope out and run some tests on this.

Given how many Gen III's there are running around Berkeley, I'll probably get one sometime soon!

 

I was spending a little time trying to figure out how I was going to wire all of this up and I realized that I have one more minor issue to deal with.

The 3 door SKS hatch switch has two buttons... one that unlocks the car and releases the hatch and one that locks the car. The 1 door SKS has a hatch with only one button... to release the hatch.

In the 3 door SKS car the switch connects to the certification ECU and in the 1 door SKS car the switch connects to the main body ECU. In both cases the switch just connects to ground.

Since it's highly likely that the connection in the certification ECU on my car is not functional I'll need to continue to use the connection on the main body ECU to release the hatch. However, I'll also need to connect that switch to the driver's door unlock contact on the certification ECU so that pressing the button will unlock the car and allow the hatch to release.

Originally I was just thinking I'd tap into that wire and run it over to the certification ECU. However, it occured to me that when I connect that in parallel with the driver's and passenger's doors that whenever anyone touches one of the door handles that connection will be brought to ground and the hatch will release. That is not really ideal

So, after all that, here are my questions... pEEf, I'm hoping you can help me here

1 - Is it possible to connect a diode between where I tap the wire going from the hatch switch to the main body ECU and where I tie it in with the other unlock switches on the certification ECU?

2 - I did a test and if you press and hold the hatch release button while the car is locked, then unlock the car while still holding the hatch release nothing happens. You need to let go of the button and press it again to release the hatch. So, if I connect it as I described above it will require two button presses to release the hatch... the first to unlock the car and the second to release the hatch. This isn't the end of the world, but I'm wondering if we (and by 'we', I mean 'you' ) could design a simple circuit that would ground the certification ECU unlock connection for a second, then ground the main body ECU hatch release connection each time the hatch release switch is pressed. That would allow it to unlock the car, then release the hatch with one button press.

Thanks for your thoughts on this

Brett

 

For those of you following this thread I have some good news and some bad news... The good news is that my parts arrived today and it looks like everything is correct. The bad news is that I've got absolutely no time to work on it this weekend, so I probably won't be able to do anything with it until Wednesday evening.

But, check back on thursday and if all goes well you should find a nice write up

Brett

 

Don't worry about that.

I only would ask you to take as much pics as you can when you do the job, and post them here, of course

Good luck.

 

I was working on my side mirrors so I have to take my door panels off. After taking off the passenger's side door panel on my Prius II, the blue harness drew my attention. Then, I took off the driver's side and realized that blue harness was connected to the SKS door handle.

zoom-in on the passenger's door

Driver's side

cable with part number

 

Thanks, Civic. Unfortunately we've already determined that the wires connected to that harness in the passenger door don't make it all the way to the ECU... they end in the junction block in the passenger footwell where all of the wires from the passenger door come in. Additionally, we've also determined that the ECU on the 1 door SKS cars is different than the one on the 3 door SKS cars and even connecting the wires to the proper locations on the ECU won't enable SKS on the passenger side.

However, the fact that there are wires that go from the door into the car make this project easier as we won't have to be trying to feed wires through there and we've also discovered that we can connect the handle in parallel with the one on the driver's side to enable SKS on the passenger door.

I already have all of the parts I need for this mod, so look back here on Thursday and if all goes well I'll have a writeup done and posted

Also note that the part number for the cable that you posted is specific to the driver's side. If you want the cable for the passenger side you need part number 89746-47040.

Brett

 

Oh! Thanks for your thorough explanation. I'd better read all 14 pages next time. I was just so excited when I saw that vacant harness on the door and remembered the discussion here. Anyhow, good luck on the mod!

 

Just a quick update on this for those of you following this thread. I've had a couple of hours to work on this over the past two days and while I'm not done yet I am about 90% of the way there... all of the hardware I bought is installed and I got the wires run from the hatch up to the front of the car, but I haven't actually connected anything to the certification ECU yet. That's probably another hour or so of work that I should get to tomorrow. After that I'll take all the pictures I've been taking (and I've been taking a lot) and put them together in a nice write up.

A couple of quick notes for those of you planning to do this yourselves... Adding SKS to the passenger door is actually quite easy. I was able to replace the door handle and add the new harness in less than 30 minutes. After that you'll need connect 5 wires to the certification ECU, but the end of the wires from the door and the ECU are only about 12 inches apart, so it will be pretty quick to make those connections as well and only involves removing a small amount of trim.

Adding SKS to the hatch is much more involved, however. It was reasonably easy to replace the one button hatch release switch with the two button switch... less than 20 minutes. The wiring harness in the hatch includes the wire for the second button. However, that wire ends above the headliner in the rear of the car. I was able to tap into that wire without removing the whole headliner, but it wasn't terribly easy and once you've got a wire connected to it you still need to run the wire from the rear roof to the front passenger footwell. This wasn't too hard, but did require removing a bit of trim and took some time.

The SKS antenna for the rear was a bit of effort as well. Technically you're supposed to remove the entire rear bumper cover to access the antenna, however, I cheated by unscrewing two screws and uncliping two clips and then I could just force the top of the bumper cover back enough that I was able to attach the antenna and run the wires from the antenna into the car in the spare tire area. As above, once you get the antenna installed you still need to get the two wires from the antenna run up to the passenger footwell. Not a terribly difficult task, and you can run these two wires plus the hatch switch wire together for some of the way, but it does also require time, removing a bit of trim... and potentially removing the rear bumper cover.

Finally, also for the hatch you need to run one more wire from the main body ECU (in the driver's side footwell) to the certification ECU in the passenger footwell. I haven't run this wire yet, but I'm hoping it won't require removing too much of the dash trim.

If all you want to do is the front passenger door then you can probably do the whole thing in under an hour... but for me, at least I think the hatch is much more useful and that probably adds two to three hours to the project.

 

awesome post cant wait for the pics