My hummer h2 03 is not gettig start it shows big lock in the dash. some one told me its security lock?

This may be related to the antitheft system The system is known for turning off the starter and/or injectors when it fails. Is there a light on the dash that says SECURITY? This is a common problem worth looking into. http://www.diy-gm-security.com/

Try charging the battery a bit by snaking the positive jumper cable underneath to the starter post where the big cable connects, and the negative jumper cable to a good ground on the frame.

The remote start isn't compatible with your hummer. The factory security system isn't able to allow a remote starter to work with it , just the way it was designed for security. You can bypass it with a adaptor but you would have to disable your security system. Most professionals won't do that, you can fin a back yard machanic to assist you. But then it affects your insurance rates now that your security system is no longer working. If you can spend the big bucks some professionals can get the viper brand of remote start to work on hummers. I've experienced this with a 07 H3 tried an inexpensive aftermarket starter it worked twice on the 3rd time it would then make my hummer go into anti-theft mode and wouldn't start engine for 10 min, the lights would work on inside it would turn over when I turned the key but it wouldn't start. I took it back to the company that installed it they woul reset it and it woul happen all over again. So I then went to a different company explained situation they again reprogrammed it and told me the last people were setting it with the driver door open so it wasn't going to start without the door open. This time the remote start only worked once then the 2nd try would go into anti-theft mode making me wait 10 min before it would start the engine. I couldn't spend the $ to try a viper brand an they charge you to uninstall them so I have since sold it and just kept the key fobs so the next owners wouldn't have the same trouble. The second company did suggest trying a relay system to see if that would solve the issue but I didn't get a chance to try it, so maybe mention trying the relay system with your currant starter before paying for a expensive system.

You can't. You need to see the dealer to have the system scanned for faults.

Possible fuel filter, fuel pump issue. Check out these items and let me know what you find.
I hope this info helps!~subyguru~

make sure all windows are closed
get out of the Hummer, using the central lock, lock the 4 doors
close the door
then open it with the KEY
then try to Start the Hummer.
(repeat several times till it works)
I am facing this problem now and that is the only soluttion I found. Untill i buy a new remote key that got stolen :S

In order not to fall in this problem, avoid opening the hummer with the key and directly locking the four doors using the central lock before starting it.

Hummers (all models) use programmable "Remote Keyless Entry" transmitters, not simply lock/unlock units.
For example, you can program the unit to make the horn "sound off" (or not) when you press the lock button once, as a confirmation that the vehicle is secure. Programming the transmitter is somewhat tricky; however, the instructions are fully documented in the owners' manual.
Since you asked "why ... ?" and not "how ...?", please consult your manual for instructions on programming your keyless remote.

Programming is tricky: inserting key in ignition, holding the lock button down for 30 seconds, then turning the key off/on and then releasing the lock button ... sheesh! .. It is beyond description.
-Gort.

u need to change/service the air compressor in ur car.
or it might be the air bags/sensors thats located next to the rear tires.

C0563 - Calibration ROM Checksum Error
Not sure what it means but thats what I found when I looked it up