Alarm System
 

I am currently researching the simplest way to by-pass the Factory Theft Deterrent System.

If anyone has done this, please feel free to jump in with your input. After I have figured it out, I will do a write up for the FAQs section.

When it is activated, the starter relay is immobilized until the door lock is locked and unlocked with the key. The horn honks and lights flash for about 1-5 minutes.

I have, over the years, read about adding a starter button to crank the starter. This is not necessarily the best way.

Also, I have read about the horns and lights coming on at random times using that method. Not wanted !

For those interested, and understanding of wiring diagrams, check these pages out and let us know what you think.


Looks like you could permanently ground the starter relay at terminal #3 to by-pass the Theft Deterrent Computer (TDC)
http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=122

http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=038

http://www.cygnusx1.net/Supra/Librar...px?S=Main&P=22

Also perhaps cut wire to #6 terminal on TDC to eliminate current to headlight circuit and alarm horn. ?? ..

http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=123

It looks like the TDC is buried up under the dash, so getting at the correct wires to cut may be near impossible.

OK...after an hour of research, it appears you can unplug, or remove, the TDC. Then ground the #3 terminal of the starter relay in the Rt. kickpanel, which will allow starter operation.

Any input???

FIRST! Look here:
http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=122


System delete:

1) REMOVE the Theft Deterrent Computer.

2) Now ground the blue wire with orange stripe (Pin 13).

3) Install good aftermarket alarm.

4) DONE.


System reset (the sure way). This is only to reset the system if you are keeping it but having issues with it... This is NOT a fix for faulty lock/hood/trunk sensors. Do this AT the deterrent ECU's connector with the battery, theft deterrent ECU and all fuses installed correctly:

1) Jumper the violet with yellow stripe wire (pin 3) to ground.

2) Jumper the blue wire with red stripe (pin 10) to ground.

3) Disconnect both and start vehicle. If it does not start after this test for a ground signal at the starter relay's coil while the ignition is held at STA. If no ground is present either the wiring or deterrent ECU are damaged. If there is then the security system is not to blame.