What is the sti connector? what does it do? What should I use it for?

[lancerevo]

What is the sti connector? what does it do? What should I use it for?

Thanks

[FB71]

STI = Self Test Input
STO = Self Test Output

Grounding the STI will send the PCM (Powertrain Control Module) into the Self Test Mode. It will then "flash-out" DTCs (Diagnostic Trouble Codes) with the 'Check Engine' lamp, and also make those pulses available at the STO, for scan tool readouts.

[Pu241]

Grounding the STI connector is also necessary to time the engine.

[lancerevo]

why it's needed to time the engine?

[lancerevo]

I have a 1995 Kia Pride 1.3 efi, have the same engine of the Festiva. As for the sti connector, I have 3 connectors as shown in the pic attacments. How should I know which one is the STI connector? Are the wire colours the same as the Festivas? I have a timing light and I tried to ground the single plug wire and when I did the ignition timing seems to advance a bit and the isle speed decreases slightly. Is this what the sti connector suppose to do? Or am I grounding the wrong wire?

[lancerevo]

I have a question for someone that have used the sti connector to time the engine. When you ground the sti, does the timing advance a little bit automatically? Pls answer

Thanks