I goggled the code and the first response was.
You don't walk into a doctor and say i am sick do you?
year model problem associated , things that are relevant might help.
http://www.toyotanation.com/forum/showthread.php?t=218046
I have been having problems with my 96 T100 for a while. It wouldnt idle a little higher to warm up, and I had to give it gas when I started it. Its got the 3.4L fuel injected. I replaced the throttle position senser (almost $100), and it didnt do anything. I finally popped a code on a long road trip, P0510, for a throttle position switch. Well, it ended up being the idle air control valve, which costs close to $300. Before you go buy expenise parts, make sure you do all the proper troubleshooting! You have to take off the throttle body to get to the IAC, but its real simple! I took off the IAC and it had a lot of carbon deposits. It read fine on the multi-meter, and when I jumperd it with power, the valve wasnt opening all the way. All it needed was a good cleaning with some throttle body cleaner and it works like new! Nice to save some cash.