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Home >> Toyota >> 2000 >> RAV4 L, AWD, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics >> Diagnostic Tests >> DTC P0120: Throttle Position (TP) Sensor Circuit >> Diagnosis & Repair
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Diagnosis & Repair

  1. Connect scan tool to Data Link Connector (DLC) No. 3. See Figure. Turn ignition on. Using scan tool, monitor throttle valve opening percentage. Opening percentage should be approximately 10 percent with fully closed throttle, and should be approximately 70 percent with throttle fully open (WOT). If percentages are as specified, problem is intermittent. Check component and ECM connections. If percentages are not as specified, go to next step.
  2. Turn ignition off. Disconnect TP sensor harness connector. Turn ignition on. Using DVOM, measure voltage between ground and terminal No. 1 (Yellow wire) at TP sensor 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  5.
  3. Check TP sensor. See ENGINE SENSORS & SWITCHES in SYSTEM & COMPONENT TESTING - 4-CYLINDER article. If problem exists, replace TP sensor. If problem does not exist, go to next step.
  4. Connect TP sensor harness connector. Access ECM behind bottom center of instrument panel, in front of console. Turn ignition on. Using DVOM, backprobe ECM harness connector and measure voltage between terminals No. 9 (Brown wire) and No. 11 (Blue/Red wire) at ECM harness connector E5. See Figure. Voltage should be .3-1.0 volt with throttle fully closed and 3.2-4.9 volts with throttle fully open (WOT). If voltages are as specified, replace ECM. If voltages are not as specified, repair open or short in wiring between TP sensor and ECM. See WIRING DIAGRAMS article.
  5. Access ECM behind bottom center of instrument panel, in front of console. Turn ignition on. Using DVOM, backprobe and measure voltage between terminals No. 1 (Yellow wire) and No. 9 (Brown wire) at ECM harness connector E5. See Figure. If voltage is 4.5-5.5 volts, repair open in Blue/Red wire between TP sensor and ECM. If voltage is not 4.5-5.5 volts, replace ECM.
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