LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1998 >> RAV4 Base, 2D Utility, AWD, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Tests W/Codes >> Self-Diagnostic Tests >> DTC P0115: Engine Coolant Temperature (ECT) Sensor Circuit >> Diagnosis & Repair
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnosis & Repair

  1. Connect scan tool to DLC No. 3 connector. See Figure. Turn ignition on. Using scan tool, monitor ECT sensor temperature. If temperature displayed is same as actual coolant temperature, check component and ECM connections. Problem is intermittent.
  2. If temperature displayed is 284°F (140°C) or more, go to step 5). If temperature displayed is -40°F (-40°C), turn ignition off. Disconnect ECT sensor connector. ECT sensor is located on coolant housing at flywheel end of cylinder head. Connect a jumper wire between ECT sensor wiring harness connector terminals. Turn ignition on. Using scan tool, monitor ECT sensor temperature.
  3. If temperature displayed is 284°F (140°C) or more, replace ECT sensor. If temperature displayed is less than 284°F (140°C), turn ignition off. Remove jumper wire. Access ECM behind bottom center of instrument panel, in front of console. Connect a jumper wire between terminals No. 4 (White wire) and No. 9 (Brown wire) at ECM E5 connector. See Figure.
  4. If temperature displayed on scan tool is 284°F (140°C) or more, locate and repair open circuit in wiring harness between ECT sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. If temperature displayed on scan tool is less than 284°F (140°C), replace ECM.
  5. Turn ignition off. Disconnect ECT sensor connector. Turn ignition on. If temperature displayed on scan tool is -40°F (-40°C), replace ECT sensor. If temperature displayed is not -40°F (-40°C), turn ignition off.
  6. Access ECM behind bottom center of instrument panel, in front of console. Disconnect ECM E5 connector. See Figure. Turn ignition on. If temperature displayed is -40°F (-40°C), locate and repair short circuit in wiring harness between ECT sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. If temperature displayed by scan tool is not -40°F (-40°C), replace ECM.
scientia non olet · About LEMON Manuals