It is in the air intake box at the front of the car.....one of the easiest PCM's to get to, but no GM dealer seems to want to tell you that.
The PCM (or ECM) is located on the interior of the car on the passenger side. To access the PCM/ECM remove the kick panel just beneath the glove box and it is right there. Disconnect the three electrical harnesses and and sucuritity clip and it's out.
On the dashboard
its beyond of the air filter.
Yes the ecm( engine control module)/ pcm( powertrain control module) are the same thing. Different manufacturers use different acronyms, ECU (engine control unit) is another often used.
Powertrain Control Module (PCM)
its on the passanger side fender
Under the dashboard , behind the glove box, passenger side.
The PCM is located under/behind the dash on passenger side of vehicle. It is very near the passenger side door.
inside the air filter housing
If you are talking about the engine pcm, is located on top of the engine on the driver side.
The pcm controls the cruise.
The ecm is located under the front passenger seat on my wife's 2000 Daewoo Lanos. This is an American version of the car.