Sounds like you're going to need a factory manual to do some deeper troubleshooting. You'll need to check wire continuity from the OBDII connector to the pins on the ECU. Maybe some wires got cut during a botched stereo or alarm install?

If the wires are OK, you could have a bad ECU.


'97 4Runner, '06 F350, '86 4Runner, '05 WR450
http://home.4x4wire.com/erik