How do I change out the ECM on my 95 Tahoe - 1995 Chevrolet Tahoe

Possible voltage drop along the wire from module to pump . Connection or corossion issue ?

Check this forum.

https://blazerforum.com/forum/2nd-gen-s-series-1995-2005-tech-41/ecm-pcm-fuse-location-95-blazer-72095/

The fuel pump control module is controlled by the ECM - engine control module , Possibility of DTC'S stored ! You need to take to Chevy Dealer !
The engine control module (ECM) supplies voltage to the fuel pump control module (FPCM) when the ECM detects that the ignition is ON. The voltage from the ECM to the FPCM remains active for 2 seconds, unless the engine is in Crank or Run. While this voltage is being received, the FPCM closes the ground switch of the fuel pump and also supplies a varying voltage to the fuel tank pump module in order to maintain the desired fuel rail pressure.

If the new ecm is stock, should need no change. Even if non-stock, if we are talking about the knock sensor, no change should be needed.

You don't say if you have checked anything else. It could be any number of issues. I would look into either the crank sensor or the ECM as possible failures. Did you have any Service Engine Soon lights recently? Have you had the ECM checked for any stored trouble codes?

What do you mean when you say "limp mode"? I've never heard that before...

Depends on the type of engine and computer. You will have to do some homework. I put a 95 Tahoe engine in a 96 Tahoe; you wouldn't think there would be much of a difference but there is. The 96 was a Vortec engine and the 95 was not so I had to change the computer and entire wiring harness over with the engine into the 96. So with that much of a gap in years you may have some issues.

It is possible that you blew the ecm fuse or damaged the ecm. When giving a jump start it is imperative that you ground the negative side of jumper cables to the engine block of the dead car and not to the battery as there will be a voltage spike that can cause serious damage as you have experienced.

I have a 96 tahoe. Check to see if one of your lights are blown, most likely it is. Whichever turn signal is blinking to fast it'll be on that side, either the front ones or the back ones.