I do believe on your model the ECM is located under the right hand of the instrument panel. If you really need to remove the ECM I would likely suggest a Haynes repair manual for this operation.
under the air box
PULL THE UNDER DASH COVER ON THE RIGHT SIDE DOWN AND THE ECM IS LOCATED TOWARDS THE FIREWALL IN A VERTICAL POSITION. YOU WILL SEE THE ECM WIRING CONNECTORS ( I THINK THERE ARE THREE WIRING CONNECTORS) GOING UP TO THE ECM.
the quad driver module is a component of the ECM. you must replace ECM.
where is the ecm on a 2000 buick lesabre
near the intake.
The ECU is located behind the glove box upper left!
Stuck/faulty fuel pump relay or possibly a faulty ECM.
The ECM powers the fuel pump relay
On the driver`s side under the steering wheel to the left