Ignition set (by-pass mode) Disconnect Plug

I have a 93 S-10 (4.6L CPI) Blazer and I want to check my ignition timing. I know that I must go into the bypass mode to do this. Ofcourse I am looking for the disconnect switch to do this. I have seen some information that says it is approximatly 1 foot from the ECM. Is this the case? If so, what if the ECM is under the dash instead of under the hood? This ignition set procedure seems to be the same for most GM's in the 90 to 95 year range (more or less)? Is there any sure method to find these plugs?

connector is under the carpet in front passenger footwell, at the top edge of the carpet. ECM is under the dash. A foot is about right.

Look for a connector with a single brown wire with a white or black tracer (can't remember colors). Disconnect that conector to adjust timing.