How to change starter selinoid - 1997 Chevrolet Camaro

https://repairpal.com/obd-ii-code-u0100-lost-communication-with-ecm-pcm-a

Start with the battery. It must have at least 10.6 volts under load to turn over the starter.

You didn't say what kind of vehicle this is but most starters have a large stud where the positive battery cable and possibly 1-2 wires that power the vehicle go, then there should be 1 wire with a small terminal that goes to the small stud marked "s". Also check the battery ground cable on both ends to make sure it's clean and tight. I hope this helps. Take care.

The click sound is the starter selinoid. you can attemt to bypass the selinoid by jumping the two big wires on the starter together and see if the starter spins. But it sounds like your starter is burned up. Time to replace it.

Your wire to the starter selinoid has some how bypassed the key switch or the selinoid is bypassed or mechanically stuck closed. The selinoid is a magnetic switch that closes the curcuit for the larger starter wire You must to make sure you are connecting the wires to the correct spots.
source:obd2 tools car diagnostic tool

Starter solenoid is on the back of the starter.

TAKE THE BATTERY OFF THE ONE SIDE OF THE SELINOID POSTIVE ONE COMMING FROM THE BATTERY KEY ON AND TOUCH IT TOO THE OTHER SIDE OF THE SELINOID WHERE THE CABLE GOES DOWN TO THE STARTER IF THE STARTER ENGAGES WITHOUT THE SENOID SO JUST A COUPLE OF SECONDS DO THIS STATER ENGAGES SELINOID BAD IF THE STATER DON'T ENGAGE THE STARTER IS BAD

Make sure you have pwr to the starter. There may be a fusible link in the starter circuit which is blown. Starter selinoid may be defective. Is there any 'clicking' like the starter selinoid is getting any power?

The starter selinoid is on top of the starter. This engages the starter when you turn the car over. Did the starter you bought have a selinoid on it?

they are part of the starter selinoid is on it.one unit