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Home >> Mitsubishi >> 1997 >> Montero LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Circuit Tests >> DTC P0120: Throttle Position (TP) Sensor Circuit Failure >> Test Procedures
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Test Procedures

  1. If using scan tool, go to step 3). Disconnect TP sensor connector. Using DVOM, check resistance between TP sensor terminals No. 1 and No. 4. If resistance is not 3500-6500 ohms, replace TP sensor. If resistance is as specified, go to next step.
  2. Check resistance between TP sensor terminals No. 1 and 3. While monitoring DVOM, slowly open throttle from idle to fully open position. If resistance does not change smoothly, replace TP sensor. If resistance changes smoothly, go to step 4).
  3. Turn ignition switch to ON position. Using scan tool, read TP sensor voltage value. With throttle at idle, value should read 300-100 me. Value should increase while slowly opening throttle. At wide open throttle, value should read 4500-5500 me. If value is not as specified, replace TP sensor. If value is as specified, go to next step.
  4. Disconnect TP sensor connector. Using DVOM, check continuity between chassis ground and TP sensor connector terminal No. 1. If continuity does not exist, repair wiring harness as necessary.
  5. Turn ignition switch to OFF position. Disconnect ECM connector. Ground specified ECM connector terminal. See TP SENSOR-TO-ECM WIRING HARNESS TERMINAL IDENTIFICATION  table. Check for continuity between chassis ground and specified TP sensor connector terminal. If continuity does not exist, repair wiring harness as necessary.
    TP SENSOR-TO-ECM WIRING HARNESS TERMINAL IDENTIFICATION

    Application Type TP Sensor Terminal No. PCM Terminal No.
    Montero 3 84
    4 81
  6. Reconnect ECM connector. Turn ignition switch to ON position. Check voltage between chassis ground and TP sensor connector terminal No. 4. If voltage is not 4.8-5.2 volts, replace ECM. If voltage is as specified, condition required to set DTC is not present at this time. Go to next step.
  7. Test is complete. Intermittent problem may exist. Road test vehicle (if necessary) and attempt to duplicate conditions that caused original complaint. Recheck for DTCs. If no DTCs are displayed, go to INTERMITTENT DTCS  .
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