LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1996 >> 4Runner Base, 4WD, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Tests W/Codes - 2.7L >> Circuit Tests >> DTC P0125 - Insufficient Coolant Temperature For Closed Loop Fuel Control >> Diagnosis & Repair
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis & Repair

  1. Connect scan tester to DLC3 connector. See Figure. Start vehicle and warm engine to normal operating temperature. Turn on scan tester. Monitor output voltage of sensor No. 1. Snap accelerate engine 3 times. Sensor should indicate a rich signal (.45 volt or more) at least once.
  2. If a rich signal is indicated at least once, replace ECM and retest. If sensor does not display a rich signal at least once, inspect circuits between ECM and sensor for open or short circuit. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If circuits are okay, replace oxygen sensor and retest.
scientia non olet · About LEMON Manuals