Diagnosis & Repair (Using OBD-II Scan Tool)
WARNING: This page is about a different car, the 2003 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.
- Check for open and short in harness and connector in VC, VTA1, VTA2 and E2 circuits between ECM and throttle control motor and sensor. See Figure. Repair or replace harness and connector as necessary. If okay, go to next step.
- Remove the glove compartment door. Turn the ignition switch ON. Disconnect the throttle control motor and sensor connector. Measure the voltage between terminals VC and E2 of the ECM connector. See Figure. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, check and replace ECM.
- Replace throttle control motor and sensor. See THROTTLE CONTROL MOTOR in REMOVAL & INSTALLATION article. Go to next step.
- Connect hand-held tester to the DLC3. Disconnect the battery terminals or remove the EFI or ECD No.1 fuse to clear DTCs. Start and run engine at idle for 15 seconds or more. Read DTC output. If no DTCs are present, system is okay. If DTCs are present, replace ECM.