I just replaced the fuel pump in my 2002 Pontiac Montana and I can hear the fuel pump working but the van still will not start. What else could be causing it?

SOURCE: where is the ecu in a 99 pontiac montana van

The ecu is located under the Air filter housing on my 99 montana

SOURCE: 2002 Pontiac Montana Thermostat replacement

check the coolant level fiirst...if that is low it wont give you any heat.....to change the thermostat you have to follow the top radiator hose to the engine.at the send of it you will see a clamp take it loose...then you will see the thermostat housing its held in place by 2 bolts . once you remove them you have the thermostat....make sure you clean all the old gasket material off both the housing and mount.also make sure you get a new gasket.

SOURCE: need to replace thermostat on pontiac montana van.

public library...Chilton or Haynes auto repair manuals or collisionrepairadvice.com     make sure you bleed the system

SOURCE: 2002 pontiac montana van ''service engine soon'' light

Diagnostic Aids

• Low system airflow can cause an intermittent complaint. Inspect for the following conditions:
  • Any restriction in the exhaust system that may produce back pressure
  • Pinched, kinked, restricted, or leaking pipes, hoses, or fittings
  • A restricted pump inlet hose, duct, or filter
  • Pinched, kinked, restricted, or leaking vacuum lines
  • Heat damage
• A short to voltage in the pump relay control circuit can result in the AIR pump running continuously with the ignition OFF by back-feeding to ground. This will eventually result in pump failure.
• An AIR pump that had become inoperative and had shown indications of having exhaust gases in the outlet port would indicate check valve failure.
• Notice Do not operate the AIR pump for more than 60 seconds. Continuous operation of the AIR pump in excess of 60 seconds will damage the AIR pump.
  
  If the DTC cannot be duplicated and is determined to be intermittent, reviewing the Failure Records data can be useful in determining when the DTC was last set. Also refer to Intermittent Conditions

SOURCE: 2002 pontiac montana passanger pwr window

I beleive you need to change the Power Window Switches Module in the drivers side door panel, as these connections are interlinked within this module and it is usually the first part that fails. Especially that you already changed the switches & motor in the passenger door and it still does not work. Once you remove the dual switch module in the driver's side door, you will understand what I mean. Plus it is really easy to access. Good luck! I have the same model, Claude