I have a 2000 SL1 Saturn and when I put the key in it will not turn. Is this the key mechanism or what???

This is a pretty common problem on GM cars. Expensive to fix, and even harder to diagnose. Read this info found on this link. It will help you understand the problem and offers some good solutions to beat this yourself. Bypassing this terrible system is a lot better than trying to have it fixed. Instead of paying the dealer mechanic to stumble thru the system and charge you for unwanted items, do this yourself.

http://vatspasslockpasskeysecurityhelp.yolasite.com/

1996-2002 SL/SL1/SL2
1996-2002 SL/SL1/SL2 Saturn
SL SL1 SL2 1996 1997 1998 1999 2000 2001 2002

First check your positive battery cable. I have seen, especially on the Saturn, where the positive cable gets corroded through the cable and will not allow any power through it. Also check all fuses in the fuse box under the hood, especially the large green 30 amp fuses. If that does not help then check the fusible link between the starter and the alternator. I have seem some of those fail, but usually the car still had power.

my 2000 saturn sl blows cold air with the heater on. I changed the thermostat,and checked out my heater core.Still blows cold air.

Sound like two different problems,Check crank sensor for dying issue.Also check ecm fuse it underhood juntion block.and injector fuse.

try putting the shifter in N and move the pressure off the wheel.

Key Is Worn Or tumblers are worn in ignition key cylinder.Will probally need new key cut & new key cyclinder with tumblers.

Air Bags For S-Series Should Fit 2000-2002 All. SDM's there are 2 part # 's One for Standard Air Bags & One For Air Bags With Side Curtain Inflators!!

Check the starter.

Check your CV joint or brake caliper.

the problem is not the bcm. the passlock security sensor is in the cylinder and housing, if the cyl and or housing was replaced the system must be relearned. if you replace the bcm you still need to relearn the system or it still will not start.