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Inspection Procedure

WARNING: This page is about a different car, the 2003 Lexus RX 300 and 2002 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check the ECU-IG fuse from the driver side junction block. Check the continuity of ECU-IG fuse. If there is continuity, go to the next step. If there is not continuity, check for a short in all the wiring harness and components connected to ECU-IG fuse.
  2. Remove the cruise control ECU with the connector still connected. Turn the ignition switch ON. Connect the positive (+) lead to terminal No. 2 (B) and the negative (-) lead to 16 (GND) of the cruise control ECU connector. If the voltage is between 10-14 volts, check the cruise control ECU. If the voltage is not as specified, go to the next step.
  3. Measure the resistance between terminal No. 16 (GND) of the cruise control ECU connector and body ground. If continuity is below 1 ohm , check and repair the wiring harness and connector between the cruise control ECU and battery. If the continuity is not as specified, repair or replace the wiring harness or connector.