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Home >> Nissan-Datsun >> 2004 >> Sentra SE-R Spec V >> Repair and Diagnosis >> External Pages >> Different car >> Section 13 (Engine Controls - Self-Diagnostics - 2.2L) >> Diagnostic Tests >> DTC P0123: Throttle Position Sensor - Circuit High Input >> Diagnostic Procedure
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Diagnostic Procedure

WARNING: This page is about a different car, the 2002 Isuzu Rodeo Sport and 2002 Isuzu Rodeo. However, it is still accessible from the selected car via links, so may be relevant.
  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. Using scan tool, read TP sensor voltage parameter. If voltage parameter is 4.78 volts or more, go to step  4 . If parameter is less than 4.78 volts, 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, check for intermittent problem. See DIAGNOSTIC AIDS  .
  4. Turn ignition off. Disconnect TP sensor 3-pin harness connector. TP sensor is located on throttle body. Turn ignition on. On scan tool monitor TP SENSOR voltage parameter. Voltage parameter should be about zero volts. If voltage parameter is as specified, go to next step. If voltage parameter is not as specified, leave harness connector disconnected and go to step  6 .
  5. Using a test light connected to battery voltage, probe TP sensor harness connector terminal No. 3 (Green wire). If test light illuminates, go to step  7 . If test light does not illuminate, go to step  10 .
  6. Turn ignition off. Disconnect PCM Blue 32-pin harness connector. PCM is located under center console in front of shifter. Turn ignition on. Check for short to voltage in Blue wire (TP sensor signal) between TP sensor and PCM. See WIRING DIAGRAMS article. If problem is found, repair as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem was found, go to step  12 .
  7. Turn ignition on. On scan tool monitor TP SENSOR voltage parameter, disconnect EGR valve sensor, MAP sensor and Fuel Tank Pressure (FTP) sensor (one at a time). If voltage parameter changes, replace component that causes change. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If voltage parameter does not change, go to next step.
  8. Turn ignition off. Turn ignition off. Disconnect PCM Blue 32-pin harness connector. PCM is located under center console in front of shifter. Turn ignition on. Check for short to voltage in Red wire (TP sensor 5-volt reference) between PCM and TP sensor. See WIRING DIAGRAMS article. If problem is found, repair as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem was found, leave harness connectors disconnected and go to next step.
  9. Check for poor or loose terminal connection in TP sensor harness connector. If problem is found, repair or replace as necessary. If no problem is found, leave harness connectors disconnected and go to step  11 .
  10. Check for open circuit in Green wire (TP sensor ground) between PCM and TP sensor. See WIRING DIAGRAMS article. If problem is found, repair as necessary. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM. If no problem was found, go to step  12 .
  11. Replace TP sensor. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
  12. Replace and reprogram PCM. See POWERTRAIN CONTROL MODULE REPLACEMENT  under POWERTRAIN CONTROL MODULE. After repair is complete, see VERIFYING VEHICLE REPAIR  under SELF-DIAGNOSTIC SYSTEM.
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