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Home >> Isuzu >> 1999 >> Rodeo LS, 2.2 D >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - Tests (2.2L) >> Diagnostic Trouble Code Identification >> DTC P0122: TP Sensor Circuit Low Input >> Diagnostic Procedures

Diagnostic Procedures

  1. Perform On-Board Diagnostic II (OBD-II) system check. See SELF-DIAGNOSTICS - INTRODUCTION article. Go to next step.
  2. Turn ignition on. With throttle closed, observe scan tool display. If TP sensor value reading is about 0.22 volt, go to step  4 . If TP sensor value does not read about 0.22 volt, go to next step.
  3. Review and record FAILURE RECORDS data on scan tool. Operate vehicle as recorded from scan tool. Using scan tool, monitor SPECIFIC DTC information for DTC P0122. If scan tool indicates DTC P0122 failed, go to DIAGNOSTIC AIDS  . If scan tool does not indicate DTC P0122 RAN AND PASSED, go to step  5 .
  4. Turn ignition off. Disconnect TP sensor. Using a fused jumper wire, connect 5-volt reference and TP sensor input terminals of TP sensor harness connector. Turn ignition on. If TP sensor reading is about 5 volts, go to step  9 . If reading is not about 5 volts, go to next step.
  5. Disconnect jumper wire. Connect a test light between positive battery terminal and TP sensor input circuit terminal of TP sensor connector. If TP sensor value reading on scan tool is about 5 volts, go to next step. If TP sensor value does not read about 5 volts, go to step  8 .
  6. Turn ignition off. Disconnect PCM. Check 5-volt reference voltage circuit for an open or shorted condition. If a fault is detected, repair as necessary. Retest system. If 5-volt reference circuit is okay, go to next step.
  7. Inspect terminals of PCM, TP sensor and harness connectors for poor connection or damaged terminals. Repair as necessary. If terminals and connections are okay, go to step  11 .
  8. Turn ignition off. Disconnect PCM. Check TP sensor input circuit for an open, short to ground or a short to TP sensor ground circuit. If a fault is indicated, repair as necessary. Retest system. If input circuit is okay, go to next step.
  9. Inspect terminals of PCM, TP sensor and harness connectors for poor connection or damaged terminals. See Figure and Figure . See WIRING DIAGRAMS. Repair as necessary. If terminals and connections are okay, go to next step.
  10. Replace TP sensor. Retest system.
  11. Replace PCM. Program replacement PCM using required equipment. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION. Retest system.
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