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Diagnosis & Repair (Using Toyota Hand-Held Tester)

WARNING: This page is about a different car, the 2002 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.
  1. Connect Toyota hand-held tester to Data Link Connector (DLC) No. 3. See Figure. Turn ignition on. Using hand-held tester, monitor APP sensor voltage for VPA and VPA2 circuits. See ACCELERATOR PEDAL POSITION SENSOR VOLTAGE  table. If voltage is not as specified, go to next step. If voltage is as specified, replace ECM.
    ACCELERATOR PEDAL POSITION SENSOR VOLTAGE

    Accelerator Pedal Volts
    Depressed
    VPA Circuit 3.2-4.7
    VPA2 Circuit 4.7-5.1
    Released
    VPA Circuit 0.3-0.9
    VPA2 Circuit 1.8-2.7
  2. Access ECM on driver's side of firewall behind driver's seat, luggage compartment lids and partition board. See Figure. Turn ignition on. Using DVOM, backprobe ECM harness connector and measure voltage between terminals No. 2 (Blue/Red wire) and No. 18 (Brown wire) at ECM harness connector E4. See Figure. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, replace ECM.
  3. Using DVOM, backprobe ECM harness connector and measure voltage between terminals No. 18 (Brown wire) and No. 20 (Blue wire) at ECM harness connector E4. With fully closed throttle, voltage should be .3-.9 volt. With fully open throttle, voltage should be 3.2-4.7 volts. Using DVOM, backprobe ECM harness connector and measure voltage between terminals No. 18 (Brown wire) and No. 19 (Black/Blue wire) at ECM harness connector E4. With fully closed throttle, voltage should be 1.8-2.7 volts. With fully open throttle, voltage should be 4.7-5.1 volts. If voltage readings are not as specified, go to next step. If voltage readings are as specified, replace ECM.
  4. Check APP sensor. See THROTTLE BODY under IDLE CONTROL SYSTEMS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article. If problem exists, replace APP sensor. If problem does not exist, repair open or short in wiring between ECM and APP sensor. See WIRING DIAGRAMS article.
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