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Home >> Mitsubishi >> 2002 >> Montero Limited >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0123: Throttle Position (TP) Sensor Circuit High Input >> Test Procedure
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Test Procedure

  1. Turn ignition on. Using scan tool, check data list item No. 14 (throttle position sensor). Turn ignition on. With throttle valve in idle position, voltage should be 0.535-0.735 volt. With throttle valve in fully open position, voltage should be 4.5-5.5 volts. If voltages are as specified, problem is intermittent. See INTERMITTENT DIAGNOSTIC TROUBLE CODES . If voltages are not as specified, go to next step.
  2. Turn ignition off. Disconnect TP sensor 4-pin connector. See Figure. Check TP sensor connector for loose, damaged, or corroded terminals. If problem exists, repair or replace connector. Go to step  8. If problem does not exist, go to next step.
  3. Check for continuity between ground and TP sensor connector terminal No. 1 (Black wire). If continuity exists, go to step  6. If continuity does not exist, go to next step.
  4. Check PCM connector D-108 for loose, damaged, or corroded terminals. If problem exists, repair or replace connector. Go to step  8. If problem does not exist, go to next step.
  5. Check for open or damage in Black wire between TP sensor connector terminal No. 1 and PCM connector D-108 terminal No. 57. If problem exists, repair Black wire. Go to step  8. If problem does not exist, replace PCM. Go to step  8.
  6. Measure resistance between TP sensor terminals No. 1 and 4 (component side). Resistance should be 3.5-6.5 K ohms. Also, measure resistance between TP sensor terminals No. 1 and 3 (component side) while moving throttle valve from idle position to full throttle position. Resistance should change smoothly in proportion to the opening angle of throttle valve. If both resistance checks are as specified, go to next step. If either resistance checks are not as specified, replace TP sensor . Go to step  8.
  7. Turn ignition on. Using scan tool, check data list item No. 14 (throttle position sensor). With throttle valve in idle position, voltage should be 0.535-0.735 volt. With throttle valve in fully open position, voltage should be 4.5-5.5 volts. If voltages are as specified, problem is intermittent. See INTERMITTENT DIAGNOSTIC TROUBLE CODES . If voltages are not as specified, replace PCM. Go to next step.
  8. Test drive vehicle following OBD-II drive cycle Other Monitor pattern. See OTHER MONITOR  under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Check for DTCs. If DTC P0123 is output, go to step  1 and retry diagnostic procedure. If DTC P0123 is not output, inspection is complete.
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