Im trying to bypass parking brake switch for pioneer AVH-P4000DVD. I already connected it to ground and then to power, but none of it works. I know that if i Install a toggle switch with 12volt current and i ground it that works, but i have 1 to many toggle switches on my dashboard.

None of the above methods will work on a newer Pioneer. You can't just ground the wire, it won't work. The wire has to see nothing on it until the radio is already on and then needs to see ground. You can do it with a switch or a relay, but just grounded it does not work.

You have to connect the ground wire and the parking brake to get pictures

remove the toggle switch and pray you didnt do damage to your delicate stereo system

better check on your dc wiring system make sure u have fixed them tightly

This can be done with a toggle switch or a relay.
**Toggle** Connect one side of a toggle switch to a ground and the other to the light green wire on the unit (parking brake input). Once the vehicle is started, just flip the toggle and apply ground. Taa-daaah.

**Relay** (see image)** This will bypass the parking brake automatically every time.

Get a relay (4 or 5 pin) from Autozone, O-Reilly, PEP Boys, etc....
Connect wires as follows on relay:
Pin #86 - Amp remote from your radio (blue wire)
Pin #30 and #85 - to a chassis ground (metal dash bracket)
Pin #87 - to Parking brake input wire on your radio (light green)
Pin # 87a - IGNORE. It isn't used in this case.

What this will do is.....
Radio will power on when you turn your key. The amp wire is delayed slightly and will trigger the relay in a second or two. This tricks the radio into thinking your e-brake has been engaged and violla....Mine has worked everyday since I connected it.

Just wanted to add my 2 cents for those who might be having the issue of no video but hear audio. I was having the same problem. I had completed the bypass hack with a single throw/single pole (SPST) toggle switch. I could bypass the warning message and hit the OK button but no video. I did hear audio. I searched everywhere but solution 4 worked for me. The thing for me was that next to the black wire on the harness wasn't empty. It had a purple/white wire with some sort of filter (labeled backup camera hook to reverse gear). I tied into this wire before the filter with another wire (I chose a black wire b/c I was grounding it) and grounded it with the black wire (ground) on the harness. I now have video! Maybe the 4 pole relay hack would have worked better but I had only done the toggle switch hack. I hope this helps others and most importantly thank you Salhi.

CONNECT A SWITHC TO THE PARKING BRAKE WIRE ONE OF THE PINS FROM THE SWITCH TO GROUND AND THE OTHER SIDE TO THE PARKING BRAKE WIRE.

ground the wire to a hot (ie power comes to the wire) switch in your dash, like a rear window defroster or seat heater. turn the switch on then off and it will trick the system into thinking you activated the parking brake.

Here is a diagram...