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Home >> Isuzu >> 2003 >> Rodeo S, 2.2 D, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.2L >> Diagnostic Tests >> DTC P0122: Throttle Position Sensor - Circuit Low Input >> Diagnostic Procedure
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Diagnostic Procedure

  1. Perform ON-BOARD DIAGNOSTIC II SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM. After performing OBD-II system check, go to next step.
  2. Turn ignition on with engine off. With throttle closed, use scan tool to observe TP sensor voltage parameter. If voltage reading is less than 0.235 volt, go to step  4 . If voltage parameter is more than specified, go to next step.
  3. Review and record FAILURE RECORDS data on scan tool. Operate vehicle within FAILURE RECORDS conditions specified. Using scan tool, monitor specified DTC information. If scan tool indicates DTC P0122 RAN AND PASSED, check for intermittent problem. See DIAGNOSTIC AIDS  . If scan tool does not indicate DTC P0122 RAN AND PASSED, go to next step.
  4. Turn ignition off. Disconnect TP sensor harness connector. TP sensor is located on throttle body. Using a fused jumper wire, jumper TP sensor harness connector terminals No. 2 (Red wire) and No. 3 (Blue wire). See Figure . Turn ignition on. On scan tool observe TP sensor voltage parameter. TP sensor voltage reading should be about 5 volts. If parameter is as specified, go to step  10 . If parameter is not as specified, go to next step.
  5. Disconnect jumper wire. Connect a test light between battery voltage and TP sensor harness connector terminal No. 3 (Blue wire). On scan tool observe TP sensor voltage parameter. TP sensor voltage reading should be about 5 volts. If voltage is as specified, go to next step. If voltage reading is not as specified, leave harness connector disconnected and go to step  8 .
  6. Turn ignition off. Disconnect PCM Red harness connector C-1. Check for open or short to ground in TP sensor 5-volt reference circuit (Red wire) between PCM and TP sensor. See WIRING DIAGRAMS  . If problem is found, repair as necessary. After repairs are complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem is found, leave harness connector disconnected and go to next step.
  7. Check for poor or loose terminal connection in PCM harness connector. If problem is found, repair or replace as necessary. After repairs are complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem is found, leave harness connector disconnected and go to step  12 .
  8. Turn ignition off. Check for open, short to ground or short to sensor voltage in TP sensor signal (Blue wire) between PCM and TP sensor. See WIRING DIAGRAMS  . If problem is found, repair or replace as necessary. After repairs are complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem is found, leave harness connector disconnected and go to next step.
  9. Check for poor or loose terminal connections in PCM harness connectors. If problem is found, repair or replace as necessary. After repairs are complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem is found, go to step  12 .
  10. Check for poor or loose terminal connections in TP sensor harness connectors. If problem is found, repair or replace as necessary. After repairs are complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem is found, go to next step.
  11. Replace TP sensor. After repairs are complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  12. Replace and reprogram PCM. See POWERTRAIN CONTROL MODULE REPLACEMENT  under POWERTRAIN CONTROL MODULE. After repairs are complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
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