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Home >> Isuzu >> 2001 >> Rodeo S, 2.2 D, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.2L >> Diagnostic Tests >> DTC P0123: TP Sensor Circuit High Input >> Diagnostic Procedures
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Diagnostic Procedures

  1. Perform OBD-II system check. See ON-BOARD DIAGNOSTIC II (OBD-II) SYSTEM CHECK  . After performing OBD-II system check, go to next step.
  2. Turn ignition on, engine off. Using scan tool, read TP sensor value. If reading is more than 4.78 volts, go to step  4 . If reading is 4.78 volts or less, go to next step.
  3. Using scan tool, read and record FAILURE RECORDS data. Operate vehicle within conditions noted in FAILURE RECORDS data. Monitor specified DTC parameters data. If scan tool displays DTC P0123 FAILED THIS IGN, go to next step. If scan tool does not display DTC P0123 FAILED THIS IGN, go to DIAGNOSTIC AIDS  .
  4. Turn ignition off. Disconnect TP sensor harness connector. Turn ignition on. Monitor TP SENSOR data. If reading is about zero volts, go to next step. If reading is not as specified, go to step  6 .
  5. Connect a test light between TP sensor harness connector Green wire and positive battery terminal. If test light does not illuminate, go to step  10 . If test light illuminates, go to step  7 .
  6. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Check for short circuit to voltage in Blue wire between TP sensor harness connector and PCM harness connector terminal E8. See Figure and Figure . Repair as necessary and retest system. If no problem was found, go to step  12 .
  7. Turn ignition on. While monitoring scan tool TP SENSOR display, disconnect MAP sensor and FUEL PRESSURE (FP) sensor (one at a time). If display changes, replace component that causes change. Retest system. If display does not change, go to next step.
  8. Turn ignition off. Disconnect PCM harness connectors. Turn ignition on. Check for short to voltage in Red wire between PCM harness connector terminal A1 and TP sensor harness connector. See Figure and Figure Repair as necessary and retest system. If no problem was found, go to next step.
  9. Check for faulty connection at TP sensor. If faulty connection is found, repair as necessary and retest system. If connection is okay, go to step  11 .
  10. Turn ignition off. Disconnect PCM harness connectors. Check for open circuit in Green wire between PCM harness connector terminal D8 and TP sensor harness connector. See Figure and Figure . Repair as necessary and retest system. If circuit is okay, go to step  12 .
  11. Replace TP sensor. Retest system.
  12. Replace and reprogram PCM using required equipment. See PROGRAMMING  . Retest system.
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