LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mitsubishi >> 2002 >> Eclipse RS, Standard >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Self Diagnostics - 2.4L >> Diagnostic Tests >> DTC P0123: Throttle Position Sensor Circuit High Input >> Diagnostic Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Procedure

CAUTION: To prevent damage to Scan Tool (MB991502), always turn the ignition off before connecting or disconnecting the scan tool.
  1. Connect Scan Tool (MB991502) to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 14, Throttle Position Sensor. With the throttle valve in the idle position, voltage should be between 0.335-0.935 volt. With the throttle valve in the full-open position, voltage should be between 4.39-5.29 volts. Turn the ignition off. If the sensor is operating properly, it can be assumed that the malfunction is intermittent, refer to INTERMITTENT DIAGNOSTIC TROUBLE CODES . If the sensor is malfunctioning, go to next step.
  2. Check connector B-07 at throttle position sensor for damage. See Figure. If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step  8.
  3. Disconnect the connector B-07 and measure at the harness side. Measure the continuity between terminal 1 and ground. The resistance should be less than 2 ohm. If the continuity is normal, go to step  6, otherwise go to next step.
  4. Check connector C-60 at ECM (M/T) or connector C-54 at PCM (A/T) for damage. See Figure or Figure . If the connector is in good condition, go to next step. If the connector is damaged, repair or replace it and go to step  8.
  5. Check for open circuit and harness damage between throttle position sensor connector B-07, terminal 2 and ECM connector C-60, terminal 92 (M/T) or PCM connector C-54, terminal 57 (A/T). See Figure, Figure or Figure . If the harness wire is in good condition, replace the ECM or PCM and go to step  8. If the harness wire is damaged, repair it and go to step  8.
  6. Disconnect the connector B-07. Measure the resistance between throttle position sensor side connector terminal 1 and 4. Measure the resistance between the throttle position sensor side connector terminal 1 and 3. Move the throttle valve from the idle position to the full-open position. Resistance should change smoothly in proportion to the opening angle of the throttle valve. If the resistance is normal, go to next step. If the resistance is abnormal, replace the throttle position sensor and go to step  8.
  7. Connect scan tool to the data link connector. Turn the ignition on. Set the scan tool to data reading mode for item 14, Throttle Position Sensor. With the throttle valve in the idle position, voltage should be between 0.335-0.935 volt. With the throttle valve in the full-open position, voltage should be between 4.39-5.29 volts. Turn the ignition off. If the sensor is operating properly, it can be assumed that this malfunction is intermittent, refer to INTERMITTENT DIAGNOSTIC TROUBLE CODES . If the sensor is malfunctioning, replace the ECM or PCM and go to step  8.
  8. Carry out a test drive with the drive cycle pattern (OBD-II). Check the diagnostic trouble codes. If DTC P0123 is output, retry the troubleshooting. If the DTC is absent, the inspection is complete.
scientia non olet · About LEMON Manuals