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Home >> Toyota >> 1996 >> RAV4 4D Utility, AWD, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Tests W/Codes >> Circuit Tests >> DTC P0120 - Throttle Position (TP) Sensor Circuit Malfunction >> Diagnosis & Repair
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Diagnosis & Repair

  1. Connect scan tester to DLC3 connector. See Figure. Turn ignition on. Turn on scan tester. Monitor throttle valve opening percentage. Opening percentage should be approximately 10 percent with fully closed throttle.
  2. Depress accelerator pedal to floor (WOT). Opening percentage should be approximately 70 percent. If percentages are as specified, inspect all connections. Problem may be intermittent.
  3. If percentages are not as specified, turn ignition off. Disconnect TP sensor connector. Turn ignition on. Using DVOM, measure voltage between ground and terminal No. 4 (Yellow wire) at TP sensor wiring harness connector. If voltage is 4.5-5.5 volts, go to next step. If voltage is not 4.5-5.5 volts, go to step 7).
  4. Check TP sensor. See ENGINE SENSORS & SWITCHES in SYSTEM/COMPONENT TESTS article. Replace sensor as necessary. If sensor is okay, go to next step.
  5. Access ECM behind bottom center of instrument panel, in front of console. Turn ignition on. Backprobing ECM connector, measure voltage between terminals No. 9 (Brown wire) and No. 11 (Blue/Red wire) at ECM E5 connector. See Figure. Voltage should be .3-.8 volt with throttle fully closed, and 3.2-4.9 volts with throttle fully open (WOT).
  6. If voltage is as specified, replace ECM and retest. If voltage is not as specified, check for an open or short in wiring harness between TP sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary.
  7. Access ECM behind bottom center of instrument panel, in front of console. Turn ignition on. Backprobing ECM connector, measure voltage between terminals No. 1 (Yellow wire) and No. 9 (Brown wire) at ECM E5 connector. See Figure. If voltage is 4.5-5.5 volts, check wiring harness for an open in Yellow wire. If voltage is not 4.5-5.5 volts, replace ECM and retest.
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