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Diagnosis & Repair

WARNING: This page is about a different car, the 2003 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
  1. Turn ignition on. Using hand-held tester or scan tool, read voltage for accelerator pedal position sensor data. See ACCELERATOR PEDAL POSITION VOLTAGE CHECK  table. If voltages are to specification, replace ECM. If voltages are not to specification, go to next step.
    ACCELERATOR PEDAL POSITION VOLTAGE CHECK

    Accelerator Pedal Position VPA VPA2
    Released .5-1.1 Volts .9-2.3 Volts
    Depressed 3-4.6 Volts 3.4-5.5 Volts
  2. Disconnect the accelerator pedal position sensor connector. Measure the resistance between the terminals of the accelerator pedal position sensor. See Figure. See ACCELERATOR PEDAL POSITION SENSOR RESISTANCE  table. If resistance is to specification, go to next step. If resistance is not to specification, replace accelerator pedal rod assembly.
  3. Turn the ignition switch ON. Measure the voltage between the terminals of the ECM E5 connector. See VPTK & VCPA VOLTAGE CHECK  table. See Figure. If voltage is to specification, go to next step. If voltage is not to specification, replace ECM.
  4. Turn the ignition switch ON. Measure the voltage between the terminals of the ECM E5 connector. See VPA & VPA2 VOLTAGE CHECK  table. See Figure. If voltage is to specification, go to next step. If voltage is not to specification, replace ECM.
  5. Disconnect the A14 accelerator pedal position sensor 6-pin connector. See Figure. Disconnect the ECM E5 connector. Check the continuity between the wire harness side connectors. See ACCELERATOR PEDAL POSITION SENSOR/ECM CONTINUITY CHECK  table. See Figure. If continuity is to specification, replace ECM. If continuity is not to specification, repair or replace harness or connector as necessary.
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