Been searching and am finding bits and pieces about the BCM. Is there a tread that tells what all it controls? I know it does the lights and more but would love to know everything it controls.

Mine is a 2001 4x4 LT

Blazeme

 

Basically the BCM controls everything except the engine. The ECM controls the engine.

 

Horn relay, high beam relay, low beams, flash to pass relay, door locks, parking light relay, turn signals, fog light relay, DRL's, chime, (key in ignition switch), lift gate latch, anti theft, passlock, RAP, (retained accessory power), Key FOB, (remote control), courtesy lamp relay, gathers data from VSS, (vehicle speed sensor) cruise control, rear lift gate ajar switch, dome override. Probably more stuff too, but it's late

The PCM, TCCM, ABS, BCM, air bag, and instrument cluster modules all share data through a network via classII serial data communications. If one module does not have the data that it needs to perform a task, it requests it from the module that has it. For example: When you select 4WD, the TCCM gathers data from the PCM, ABS and BCM. It processes the data and determines if a transfer case shift is allowed. If everything is correct, it commands the encoder to shift the transfer case, and away you go in 4WD.

This almost scratches the surface on what the BCM does

 

So if I roll down the window the door switch tells the bcm to close a relay? We have had random times were the drivers side window stops working, wont go up or down. Wait a bit and it starts working again.

Already replaced the door switch. Thinking maybe a relay is bad or wiring or even BCM problem.

 

BCM is not really (from my knowledge) something that goes bad too easily.
Since you replaced the switch and still the same thing, I would guess the wiring or the motor.... is there a relay for putting the window up and down?

I dont know for that, I thought it was just 12v, push the button and it puts power to the motor in either direction to make it go up or down.
But then again, I own a first gen

 

The BCM does not control power windows. There are no relays in the circuits. Inside the switch there is a self resetting circuit breaker. In the "express down" mode, when the window reaches the full down position in the tracks, the motor binds up which causes amperage draw to increase, and the breaker trips. After a few seconds, the breaker resets and the switch will control the window again. If the breaker is weak, the motor is failing, or the glass binds in the tracks, (going up or down), the breaker will trip.

 

Thanks Captian Hook that sounds like just what I needed to know.

Blazeme