My 2000 grand am will not start! on top of the security defect, now it won't turn over. I thought it was my battery but everything else works, but it seems like it doesn't have enough battery power to start the car. and when i try to start it sometimes the trunk will pop open by itself! What's going on now?

It could be many things, and I tend to favour the security system after a battery disconnect. Is the security light on?

https://www.google.com/search?q=2009+highlander+cranks+but+won%27t+start+after+disconnecting+battery

..

security problem in ur key just get a new key made or ur key chip recharged if that doesn't work may have to get ur security bipassed

solved by owner

Yes, everything you need to know is on this site.
http://vatspasslockpasskeysecurityhelp.yolasite.com/

make sure the battery is fully charged,, if the alternator isn't working right , everything is run off the battery for a short time, and it will just die , the lights and other functions like the radio require little voltage to work, so try that first, if it turns over fast ,, then you need to check for fuel, if the pump is weak, it could be not enough pressure to keep the car running

Is your security light flashing? If so, your onboard security system has disabled the starter. The security system can be reset (providing you are using the ORIGINAL key for the car) you may have to hook up a battery charger to accomplish this. First hook up the battery charger then when you get in the car, set the parking brake before turning the ignition on. This will keep the daytime running lights from coming on. Then turn the key to the RUN position and wait for the security light to stop flashing. (This takes about 10 minutes.) Then, without turning the key off, turn the key to the START position. The engine should start.

If this doen't work, you will probably have to wait until your wife gets home so you can reset the security system by using the remote to lock the unlock the doors.

I would also recommend investing in a second remote and key so you don't have this problem in the future. The second key and remote is pretty easy to progrm on your vehicle. This can be done either by the dealer or most aftermarket repair shops. You MAY even want to try to do it yourself. Instructions for programming additional keys and remotes are located in your Owner's Manual.

I have the same problem few days ago, and still didn't find any solution. Can any one please help?????8

starter/soleniod..give it a tap with a hammer a few times and then try..both of them 1 at a time to see which one it is..u can check if u have power going to it first..if not it might b ur fuseable link of even ur starter relay..

Neutral safety switch may be going bad or is out of adjustment. Switch is on the transmission under the shift linkage ear where shift cable attaches. Loosen it and put car in reverse (not running) turn switch so that reverse lights come on. semi-tighten switch and check that it starts in both park and neutral. If not you need to change the switch.