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Home >> Suzuki >> 2002 >> Grand Vitara Limited, RWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0123: Throttle Position (TP) Sensor Circuit, High Input >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. Perform DTC CONFIRMATION TEST  . If DTC P0123 is set, go to next step. If DTC P0123 is not set, problem is intermittent. System is okay at this time. See INTERMITTENTS TROUBLE SHOOTING - NO CODES article.
  2. Turn ignition off. Disconnect TP sensor connector. Turn ignition on. Measure voltage between ground and TP sensor harness connector terminal No. 3 (Gray/Red wire). If 4.5-5.5 volts exist, go to step  4 . If 4.5-5.5 volts do not exist, check for open in Gray/Yellow wire between TP sensor and ECM (PCM) 26-pin connector C51-3 terminals No. 20. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repair as necessary and go to DTC CONFIRMATION TEST  . If wire is okay, go to next step.
  3. Check for short to power in Gray/Red wire between TP sensor and ECM (PCM) 26-pin connector C51-3 terminals No. 11. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Repair as necessary and go to DTC CONFIRMATION TEST  . If wire is okay, disconnect ECM (PCM) 26-pin connector C51-3. Check for poor terminal contact at ECM (PCM) 26-pin connector C51-3. If poor terminal contact is found, repair as necessary and go to DTC CONFIRMATION TEST  . If terminal contact is okay, replace ECM (PCM) and go to DTC CONFIRMATION TEST  .
  4. Check TP sensor operation. See THROTTLE POSITION SENSOR in SYSTEM & COMPONENT TESTING article. Replace as necessary and go to DTC CONFIRMATION TEST  . If TP sensor is okay, check for short to power in Red/Green wire between TP sensor and ECM (PCM) 26-pin connector C51-3 terminals No. 12. If wire is okay, replace ECM (PCM) and go to DTC CONFIRMATION TEST  .
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