Toyota Repair: 2003 toyota tacoma high idle speed, air control valve, dead battery

Question
i have an 03 tacoma s-runner,3.4 5 speed manual with a bit over 100,000 miles-just replaced clutch and transmission in the truck-truck had been running fine(except for the transmission woes) and was out of operation for about a year. got truck back together, and started it, had to jumpstart due to dead battery-noticed very high idle at startup, but allowed it to warm to operating temperature, and idle never came down below 1500-1700 rpm. battery is not holding charge, but i let the truck run a long time, so i figure it had enough time to level out, if it were ever going to-everything i check online points to a bad idle air control valve, but before i tear into that, is there a scan tool i can hook it to to test for what can be causing this high idle condition? any information you can provide would be most welcome.

Answer
If the check engine light is not on I doubt that there are any trouble codes in the ECM.It could very well be a problem with the IAC valve, try removing the throttle body and then the IAC valve, clean both of them with some air intake cleaner and a soft brush, if the IAC valve is stuck and won't free up it should be replaced.