LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2002 >> 626 ES, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 2.5L >> Diagnostic Tests >> DTC P0123: TP Sensor High Input >> Diagnosis & Repair Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis & Repair Procedure

  1. Perform DTC confirmation procedure. See DTC CONFIRMATION PROCEDURE  under SELF-DIAGNOSTIC SYSTEM. Check for DTCs during KOEO and KOER self-test. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If DTC P0123 is present, go to next step. If DTC P0123 is not present, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
  2. Turn ignition off. Disconnect TP sensor connector. Check for damaged or corroded sensor connector terminals. Repair as necessary, and go to step  7 . If connector terminals are okay, go to next step.
  3. Check TP sensor operation. See SYSTEM & COMPONENT TESTING - MIATA, MILLENIA, MPV, PROTEGE, PROTEGE5 & 626 article. Replace as necessary and go to step  7 . If TP sensor is okay, go to step  7 .
  4. Disconnect PCM connector. Check for damaged or corroded PCM connector terminals. Repair as necessary, and go to step  7 . If connector terminals are okay, go to next step.
  5. Check for continuity of Black/Yellow wire between TP sensor harness connector terminal "A" and PCM harness connector terminal No. 91. See Figure . If continuity is present, go to step  7 . If continuity is not present, repair open in Black/Yellow wire. See WIRING DIAGRAMS article. Go to step  7 .
  6. Turn ignition on. Measure voltage between ground and TP sensor harness connector terminal "C" (Violet/Yellow wire). If 4.79 volts or less are present, go to next step. If more than 4.79 volts are present, repair short to reference voltage and go to next step.
  7. Reconnect all connections. Turn ignition on. Clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. Perform KOEO and KOER self-test. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If DTC P0123 is present, replace PCM and go to next step. See REMOVAL, OVERHAUL & INSTALLATION article. On vehicles equipped with immobilizer system, reprogram ignition key identification numbers. See COMPUTER RELEARN PROCEDURES - IMPORT article in GENERAL INFORMATION. If DTC P0123 is not present, go to next step.
  8. Perform DTC confirmation procedure. See DTC CONFIRMATION PROCEDURE  under SELF-DIAGNOSTIC SYSTEM. Check for DTCs. See RETRIEVING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. If any other DTC is present, go to appropriate test.
scientia non olet · About LEMON Manuals