Hello
I feel ready to move forward and do something a little more advanced stuff. I think I will hack one of my old toy cars, but I got a small problem. I do not know how I find the pins that steer the motors? It looks about like this (This image is borrowed from dinofab.com, but it also looks like my car):
How do I find out which of these pins is the pins that steer the motors?
Thanks for your help! : D
Why not trace back from the motors?
Probably not AUD1, X0, X1, GND, RX, TX, RES or 4.5V.
How do i trace back from the motors? 
Find where a trace the motor, then follow the trace back to that chip that you showed us a picture of. Write down which pin it attaches to. Repeat until you've traced back all the motors :).
yep, start at the motor and follow the wire back to the chip
Well if you want to use an arduino to control it then maybe you want to be reading the serial data sent past the tx and rx pin. Then you can probably work out what code is sent to steer the motor etc and so it that way.
Much more interesting that way too 
Mowcius
Yeah it can be fun to experiment and try different methods.
To trace this easily, take the board, lay it flat on a scanner square with the edges, and scan it, both the front and the back. Play with the resolution; the smaller the traces, the higher the scan resolution you should use. Then use a tool like PhotoShop or the Gimp to flood fill the traces (filling "similar" colors) from part to part, via to via, in a contrasting color (yellow or red work well). This is a real handy way to trace and reverse engineer a board, even when it has small, close-together traces for SMT work; just increase the resolution of the scan to make everything larger so the flood fill can work properly. Its not a perfect method, but when used in conjunction with standard tracing methods (namely looking at it until your eyes bleed), it can be a great help.
Yeah, works great for double-sided and multi-layer boards!
Yeah, works great for double-sided and multi-layer boards!
For double sided boards, you can set up layers and invert/flip the bottom/top (whichever one you consider "the other side"), and alter the alpha channel for a particular color to allow "see thru"; stack them as layers in your editor, and alter the transparency to allow you to see the traces as you track them.
Obviously this won't work for multi-layer boards, but even in that circumstance using this method may reveal clues that can help you find nearby pins and such.
I know all of this from experience; many moons ago I was involved in the "hacking" of a set top box called the Acer NT-150, which inside was essentially a AMD 586/133 motherboard with extra components for TV signal mixing (among other things; it also had a built in smart card reader). People wanted to add a mouse, which it lacked; one of the members of the group showed me the solution he used for tracing pads from the Super I/O chipset to empty pads of what looked like a MAX232 chip on the motherboard - he and several others used this method over a period of about a week to reverse engineer the chip, which was then sourced, soldered in place, and gave the board back a DB9 serial port for a mouse.
So I know the method is more than valid for this purpose, even on a multi-layer board like a PC motherboard.
... if all else fails there is always the tradition "ohm it out" method.