LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mitsubishi >> 2001 >> Eclipse GS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0121: Throttle Position (TP) Sensor Circuit Range/Performance Problem >> Diagnostic Procedure (2.4L)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedure (2.4L)

  1. Turn ignition on. Using scan tool, check data list item No. 14 (throttle position sensor). With throttle valve in idle position, voltage should be 0.535-0.735 volt. With throttle valve in fully open position, voltage should be 4.5-5.5 volts. If voltages are as specified, problem is intermittent. See INTERMITTENT DIAGNOSTIC TROUBLE CODES  . If voltages are not as specified, go to next step.
  2. Turn ignition off. Disconnect TP sensor 4-pin connector. Check TP sensor connector for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step  14 . If problem does not exist, go to next step.
  3. Turn ignition on. Measure voltage between ground and TP sensor connector terminal No. 4 (Green/Yellow wire). See Figure . Voltage should be 4.8-5.2 volts. If voltage is as specified, go to step  6 . If voltage is not as specified, go to next step.
  4. Turn ignition off. Disconnect ECM connector C-60 or PCM connector C-54. Check ECM connector C-60 or PCM connector C-54 for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step  14 . If problem does not exist, go to next step.
  5. Check for open or short to ground in Green/Yellow wire between TP sensor connector terminal No. 4 and ECM connector C-60 terminal No. 81 or PCM connector C-54 terminal No. 46. See Figure and Figure . If problem exists, repair Green/Yellow wire between TP sensor and ECM/PCM, then go to step  14 . If problem does not exist, replace ECM/PCM, then go to step  14 .
  6. Turn ignition off. Check for continuity between ground and TP sensor connector terminal No. 1 (Black wire). If continuity exists, go to step  9 . If continuity does not exist, go to next step.
  7. Disconnect ECM connector C-60 or PCM connector C-54. Check ECM connector C-60 or PCM connector C-54 for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step  14 . If problem does not exist, go to next step.
  8. Check for open or damage in Black wire between TP sensor connector terminal No. 1 and ECM connector C-60 terminal No. 92 or PCM connector C-54 terminal No. 57. See Figure and Figure . If problem exists, repair Black wire, then go to step  14 . If problem does not exist, replace ECM/PCM, then go to step  14 .
  9. Measure resistance between TP sensor connector terminals No. 1 and 4 (component side). See Figure . Resistance should be 3.5-6.5 k/ohms. Measure resistance between TP sensor connector terminals No. 1 and 3 (component side) while slowly opening throttle valve from idle position to fully open position. Resistance should change smoothly in proportion to opening of valve. If resistance is not as specified or does not change smoothly in proportion to throttle opening, replace TP sensor, then go to step  14 . If resistance is as specified, go to next step.
  10. Check ECM connector C-60 or PCM connectors C-54 and C-57 for loose, damaged or corroded terminals. If problem exists, repair connector, then go to step  14 . If problem does not exist, go to next step.
  11. Check for open or short to ground in Yellow wire between TP sensor connector terminal No. 3 and ECM connector C-60 terminal No. 84 or PCM connector C-57 terminal No. 78. If problem exists, repair Yellow wire, then go to step  14 . If problem does not exist, go to next step.
  12. Check for short to ground in Yellow wire between TP sensor connector terminal No. 3 and auto cruise control ECU connector terminal No. 1. See Figure and Figure . If problem exists, repair Yellow wire, then go to step  14 . If problem does not exist, go to next step.
  13. Turn ignition on. Using scan tool, check data list item No. 14 (throttle position sensor). With throttle valve in idle position, voltage should be 0.535-0.735 volt. With throttle valve in fully open position, voltage should be 4.5-5.5 volts. Turn ignition off. If voltages are as specified, problem is intermittent. See INTERMITTENT DIAGNOSTIC TROUBLE CODES  . If voltages are not as specified, replace ECM/PCM, then go to next step.
  14. Test drive vehicle following OBD-II drive cycle other monitor pattern. See OTHER MONITOR  under OBD-II DRIVE CYCLES under VERIFYING REPAIRS. Check for DTCs. If DTC P0121 is output, retry diagnostic procedure. If DTC P0121 is not output, inspection is complete.
scientia non olet · About LEMON Manuals