Diagnostic Procedure
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2002 Toyota Tundra, 2002 Toyota Tacoma, 2002 Toyota Sequoia, 2002 Toyota 4Runner, and 2001 Toyota Tundra. However, it is still accessible from the selected car via links, so may be relevant.
- Remove the transfer L4 position switch. Ensure that there is continuity between switch terminals. See Fig 1. When pushed, there should be continuity and when released, there is no continuity. If test is as specified, go to next step. If test was not as specified, replace the transfer L4 position switch.
- Remove the ECM with the connectors still connected. Turn the ignition switch to the ON position. Measure the voltage between terminal L4 of the ECM and ground when the transfer case is in the L4 position. See PIN VOLTAGE TESTS . Voltage should be less than 1.5 volts, and when in gear except L4 position, voltage should read 9-14 volts. If voltage is not as specified, go to next step. If within specifications, see SYMPTOM DIAGNOSIS under TROUBLE SHOOTING.
- Check the wiring harness between the transfer L4 position switch and the ECM for an open circuit or a short. If no problem was found, replace the ECM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. If a problem was found, repair or replace the wiring harness and connector.