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Home >> Toyota >> 2000 >> RAV4 Base, AWD, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics >> Diagnostic Tests >> DTC P0115: Engine Coolant Temperature (ECT) Sensor Circuit >> Diagnosis & Repair
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Diagnosis & Repair

  1. Connect scan tool to Data Link Connector (DLC) No. 3. See Figure. Turn ignition on. Using scan tool, monitor ECT sensor temperature. If temperature displayed on scan tool is same as actual coolant temperature, problem is intermittent. Check component and ECM connections. If temperature displayed on scan tool is 284°F (140°C) or more, go to step  4. If temperature displayed on scan tool is -40°F (-40°C), go to next step.
  2. Turn ignition off. Disconnect ECT sensor harness connector. Connect a jumper wire between ECT sensor harness connector terminals. Turn ignition on. Using scan tool, monitor ECT sensor temperature. If temperature displayed on scan tool is 284°F (140°C) or more, replace ECT sensor. If temperature displayed on scan tool is less than 284°F (140°C), go to next step.
  3. Turn ignition off. Remove jumper wire. Access ECM behind bottom center of instrument panel, in front of console. Using a jumper wire, backprobe between terminals No. 4 (White wire) and No. 9 (Brown wire) at ECM harness connector E5. See Figure. If temperature displayed on scan tool is 284°F (140°C) or more, repair open in wiring between ECT sensor and ECM. See WIRING DIAGRAMS article. If temperature displayed on scan tool is less than 284°F (140°C), replace ECM.
  4. Turn ignition off. Disconnect ECT sensor harness 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), go to next step.
  5. Turn ignition off. Access ECM behind bottom center of instrument panel, in front of console. Disconnect ECM harness connector E5. See Figure. Turn ignition on. If temperature displayed is -40°F (-40°C), repair short in wiring between ECT sensor and ECM. See WIRING DIAGRAMS article. If temperature displayed by scan tool is not -40°F (-40°C), replace ECM.
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