Support Thread for Speed Lock Override sold in the PC Shop

Not sure if you can do that because the steering wheel buttons activates its own set of resistor value on the same wire. Instead of running 10 wires for 10 buttons, they run 1 wire to the steering wheel. Each of the 10 button has its own resistor. Temp Up might be 330 ohm while Temp down might by 660 ohms. In order for you to do the hack like you wanted, you'll need a way to decode the Temp Up to activate 1 relay and Temp Down to activate another relay and you'll have to get the signal from the same wire. You'll probably have to reverse engineer Steering Wheel Audio Control Adapters.

Edit: This guy has similar idea Acura steering wheel volume control implementation

 

Blank switch filler options!!! The next batch of bypass will have the option to order a single switch or a dual switch blank filler. Of course only 1 switch will operate the bypass. However, the second switch is there for you to add your own accessory. You can use any mini rocker switch with 13mm X 19mm mounting hole +/- .5mm tolerance. Switch not included. Dual switch filler option will be slightly higher cost.

My first attempt at dual switch in a single blank is in fall of 2010 and I failed. It still holds the switch together, just not pretty. I cut the ABS freehand and filed til it kind of fit. I didn't file the stock opening. That's why the switches don't sit flush. See second attempt on filing.



My second attempt was in Jan 2014 for my Sienna. I took a shop made blanks and filed for 2 hours to get 2 switches to fit.


Notice the shop made blank filler has 3 layers of ABS sheet sandwiched together.


There's no divider for the 2 switches so when the 2 switches snapped in, the thin wall bold out a little bit.



The stock blank opening is almost 18MM wide. These mini switches are over 19MM long. They will not fit the stock opening without shaving.


In order to fit 2 switches, you'll need to shave the side of the hole to just over 19MM. No need to shave the top/bottom.


Once the holes are widen, the switches and the blank fillers will sit flush and look quite nice. Please DO NOT shave the top and bottom of the hole. It is not necessary to mount 2 switches in the stock blanks. Even with widen hole, the stock blank fillers can still be inserted and fit snugly. Top switch is for the speed lock override and the bottom switch is for turn signal activated rear camera.



I placed an order for the single switch and dual switch from my local plastic shop. They can make the single switch blank fillers without problems. They've tried for almost 2 months without success to make the 2 switch blank fillers. For me, it's all or nothing so I have canceled the order with them. I have since purchase a 3D printer and print the blank fillers myself. It works out better because when Toyota changes their dash switches, I can redesign the blank fillers to fit the new blanks. I won't get stuck with bunch of old blank fillers that won't fit the redesigned switches. This is my third attempt with 3D printed blank fillers.


The single switch blank filler doesn't look pretty. I believe with a little sanding, it should look much better.


Compared with dual switch blanks from the plastic shop. This is their 5th attempt to successfully make a functional 2 switch blanks.


The shop made blanks filler's switch alignment is crooked and there's a gap between the 2 switches. The 3D printed switch blank filler is near perfect with no gap.

3D printed single switch blank filler in 2010 Prius lower cigarette lighter panel.

dual switch blank filler in a 2014 Sienna cigarette lighter panel/seat heater panel(for fitness and testing purpose. Seat heater switch will back in.)

 

When vehicle is stopped, the VSS rests at 12V+ or ground. Cutting the VSS wire or feeding it straight 12V+ or ground will cause the head unit to ignore VSS signal and switch to GPS signal for speed. The radio will keep ignore the VSS signal for another half minute after it receives the true VSS signal. After which time you can do again. With the bypass in place, the head unit never switch to GPS signal for speed so you can activate the bypass for as long as you want.

 

After countless hours of experimenting with my Prius, I concluded that the head unit compares the GPS speed against the VSS speed. If GPS signal indicates that the vehicle is moving at a speed greater than 0MPH but the VSS signal shows the vehicle is not moving at all, the head unit sets the GPS signal priority over VSS. During the time where GPS receives no signal from satellite, the head unit relies on the VSS for speed. The head unit has its own gyro sensor and compass so it knows which way you're traveling and turning. Ever drive in a curved tunnel?
If you're driving in a 20 mile tunnel, the head unit theoretically will allow you to override the speedlock with a severed VSS wire or a straight 12V+ or ground until you exit the tunnel. After which, the head unit will change to GPS signal for speed once you come out of the tunnel because it's receiving a good signal.
During my research on bypassing the speed lock, I have tried severing the VSS wire, feeding only 12V+ and feeding only ground. All 3 have resulted in the same. The head unit ignore the VSS signal and GPS speed took over. What's worse is that once you've connected the VSS wire, the head unit ignore it for additional 30 seconds. During that time, any attempts to bypass the speedlock with severing, +12V or ground are useless. Once the head unit switches back to VSS for speed, you can then repeat the bypass.
I believe Prestigious society bypass both VSS and GPS antenna but I'm not sure. I've never used their product.

 

New Speed Lock Override 1 SLO1 wiring diagram

 

Can I feed the power to the bypass from the power going to the head unit?
Yes, as long as it's switched on by the key and not constant on. You don't want a power vampire in your electrical system.

Where to connect the ground? Do I connect it to any - wire or to a ground point?
Any good ground spot will work.

How much time do you recommend keeping the bypass on? I'll use that video input to connect my iPhone and showing
the maps while driving.
I've left it on for about an hour before and I didn't have any problems. Keep in mind that 2014 Camry's head unit also display car info. I don't know if the head unit is merely a display for an outboard trip computer or if it uses the VSS information to do the mileage calculation onboard. Bypassing the speedlock may or may not affect the mileage display on the screen. You can check out the toyotanation's Camry aux video input thread for more infomation.

 

Are you using the LED to test the outpout of the 555? Is the LED made for 12V? The LED I used to test the output is a domelight LED. If you're using a 3.3V LED, the timer output will burn it without proper resistor, 470 ohm. If you're using the correct LED for testing the output then check the 4.7uf capacitor. The stripe on the capacitor goes to ground. I had a few that didn't work and it was caused by reverse polarity capacitor.

 

Use 4.7uf capacitor with 1M ohm to 1.5M ohm for R2.