Tundra 4.7L
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 2003 Toyota Tundra, 2003 Toyota Tacoma, 2003 Toyota Sienna, 2003 Toyota Sequoia, and 2003 Toyota Land Cruiser. However, it is still accessible from the selected car via links, so may be relevant.
For starter signal circuit inspection, see DTC P0617: STARTER RELAY CIRCUIT HIGH under DIAGNOSTIC TESTS in SELF-DIAGNOSTICS - TUNDRA V8.