I just bricked my 2012 prius..how screwed am I?

Im an experienced 12 volt tech. But yesterday my confidence got the better of me. I made a big mistake by trying to work on car while the battery connected. God, what a dumb nice person move.

I was make an addition to my after market alarm/remote starter. I was putting in a "improved" version of my "starter kill" based on the "ground when armed' output of the alarm box.

I had already successfully done this, by cutting the first yellow wire in on the PTS button plug, and soldering extension wires too both those yellow cut points in the wire, and running them into a relay which would keep the button dissabled until the after market alarm was disarmed. This would close the yellow wires back together, returned full function to the PTS button. Worked perfectly.

While upgrading my compustar key fob, I noticed my soldering job on that relay was a bit sloppy, so I wanted to redo it. In so doing, I accidentally touched a constant +12 to the wrong pin, and I think it fed 12 volts up my starter kill lines and directly into the yellow wire of the PTS IMMO/Amplifer module, it likely also fed 12 volts down the other yellow end, right into the car (where ever it goes). no sparks, no blow fuses, all seemed well.

When done with my job, I went to send the new 3 mile key fob. Worked perfect. I could arm/lock and disarm/unlock the car. I tried remote start....worked prefect, started right up, went to ready, no error codes. Next I tested my work...stayed in the car, shut it off, armmed it. Checked my starter kill relay, open. Pressed the break, nothing, put my sks key up to the button, no beep no led, ignores push. Perfect. (remember the relay is open now, and the yellow wire appears cut from the car).

Feeling pretty good about myself, I retired for the night.

Today, I disarmed, got in, held my sks key up to the button (I have no battery in my sks key) and got no beep. oh shit. Pressed the break, no green led, no orange leds, and my heart sank.

The red flashing led in the dash showing the immobilizer is on, stays on, even during dissarm, and even when I put my key up too it. I unhooked my wires, tied the yellow wires back together, no difference. oh shit. I remote started it, worked, right to ready, no errors. But as we all know, you cant put the car in gear with a remote start, because when you press the break it kills the car, and demands a PTS restart.

How screwed am I?

 

Not sure what you mean by that? The 12volt battery is strong, and I can remote start the car.

 

Im praying its the PTS module is broken, its easy to change and not expensive. I dont think there is any programming stored in it, all the key codes are in the ECU I think. I even have an extra PTS factory oem module Im gonna try.

 

I did not try that. I will tho, thanks. Would there be any indication of a code on the dash? or not necessarily?

 

Ok guys, I got S U P E R lucky. I did cause damage to he SKS system, but it only broke the PTS button assy. I just happend to have an extra one of those I got off ebay just last week for a different project I had in mind. So this morning, on a whim, I drove to the dealer in my borrowed van, and go premission to go to the back, where my car was dropped off by the tow truck. I swapped out the PTS assy, and everything came back to normal and Im good again. No damage to the ECU, thank the lord. The service manager told me to go by a lottery ticket today.

 

On that note, can any of you tell me what the pin out of the PTS button assy (Imobolizer/Amplifer) is. Its a 14 total pin connector, and the wires are as follows:

top row (smaller holes):

thick pink 1
thin purple 2
thin blue 3
thin green 4
thin red 5
thin green (different green) 6
thick yellow 7

bottom row (bigger holes):

blank 1
thick yellow 2
blank 3
blank 4
thick white 5
blank 6
thin black 7

Id very much like to know what each of these wires do, and how they should test (with meter/scope).

2012 Toyota Prius

 

PTS = "Push to Start"

 

After playing with my bad pts module, taking it apart and trying to figure how it works I have come up with this so far:

thick white wire is ground. pushing the button connects this ground to the thin black, and the thick yellow wires right next too it. 100%

Also that ground is the cathode of all leds. One led is green only, and its job is to light up the face plate of the "POWER" text printed on the button. The anode (+12) side of that led is the thin green in the middle bottom row. 100%

The other led is a green and orange with common ground (cathode) also on the thick white wire. 100%
The orange side off the LED anode (+12) is the other thin green wire. 100%
The green side of that LED anode (+12) is the thin red wire . 100%

I think the other yellow wire (the one I muffed up) is +5volts in to run the RF radio chip. 60% sure.
That puts the pink wire as ground for the radio chip. I think. 60% sure.

After the chip reads the code number from the smart key via its wireless antennas, it outputs this code on the blue or pink wire.
Im 50% of this.

Me accidentally shooting 12 volts DC down the yellow wire, over-loaded the power input. It only wants 5 volts, not 12. Looking up the part number of the chip, the max input voltage is 7 MAX, and only then for a short time.

What was learned :

*Always disconnect 12 volt batter when working on stuff.
*The LED's share a common ground, and are not controlled by the module, external +12 signals down the two green wires and red wire turn them on, the circuit board only has the current limit resistors on it.
* Using the yellow wire is a prefect choice for alarm stater kill, because it cuts power to the decoder RF chip. The car can not be started with a smart key with this wire open.