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Home >> Suzuki >> 2002 >> Esteem GLX, 4D Sedan, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 1.8L >> Diagnostic Tests >> DTC P0123: Throttle Position Sensor Circuit - High Input >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. If engine system check has been performed, go to next step. If engine system check has not been performed, go to A4: ENGINE SYSTEM CHECK  under SYSTEM TESTS.
  2. Turn ignition off. Connect scan tool. Turn ignition on. Observe THROTTLE VALVE OPENING percentage on scan tool while slowly opening throttle valve to fully open position. If display reads 100 percent trough entire range, go to next step. If display does not read 100 percent through entire range, problem is probably intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
  3. Turn ignition off. Disconnect TP sensor 3-pin harness connector. Check for poor terminal contact at TP sensor harness connector. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If no problem is found, go to next step.
  4. Turn ignition on. Measure voltage between ground and TP sensor harness connector terminal No. 2 (Gray wire) and No. 3 (Pink/Green wire), individually. See Figure . If 4-6 volts are present at each terminal, go to step  8 . If 4-6 volts are not present at each terminal, go to next step.
  5. Check for short to power in Pink/Green wire between TP sensor and ECM harness connector C20 terminal No. 18. Also check for open in Gray wire between TP sensor and ECM harness connector C20 terminal No. 25. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If no problem is found, go to next step.
  6. Check for poor terminal contact at ECM harness connector C20. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If no problem is found, go to next step.
  7. Substitute a known good ECM, and repeat DTC CONFIRMATION TEST  . If DTC does not reset, testing is complete.
  8. Measure resistance between specified TP sensor terminals. See CHECKING THROTTLE POSITION SENSOR RESISTANCE  table. See Figure . If resistance is as specified, go to next step. If resistance is not as specified, replace TP sensor. After repair, repeat DTC CONFIRMATION TEST  .
    CHECKING THROTTLE POSITION SENSOR RESISTANCE

    Measure Between TP Sensor Terminals No. (1) Specification (K/Ohms)
    1 & 2 .1-6.5
    1 & 3 4-6
    (1) TP sensor voltage should change slowly and smoothly from low value to high valve as throttle is opened.
  9. Check for open or poor terminal connection in Orange wire between TP sensor and ECM harness connector C20 terminal No. 27. See WIRING DIAGRAMS article. If problem is found, repair as necessary. If no problem is found, go to next step.
  10. Substitute a known good ECM, and repeat DTC CONFIRMATION TEST  . If DTC does not reset, testing is complete.
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