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Home >> Toyota >> 2000 >> RAV4 Base, AWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 17 (Engine Control System Self-Diagnostics) >> Diagnostic Tests >> DTC P0115: Engine Coolant Temperature (ECT) Sensor Circuit >> Diagnosis & Repair
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Diagnosis & Repair

WARNING: This page is about a different car, the 2000 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
  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 below stereo, behind instrument panel, just in front of center console. On models with 4A/T transmission, connect a jumper wire by backprobing between terminals No. 14 (White wire) and No. 18 (Brown wire) at ECM harness connector E8. See Figure. On models without 4A/T transmission, connect a jumper wire by backprobing between terminals No. 4 (White wire) and No. 9 (Brown wire) at ECM harness connector E5. See Figure. On all models, temperature displayed on scan tool should be 284°F (140°C) or more. If temperature displayed on scan tool is as specified, repair open in wiring between ECT sensor and ECM. See WIRING DIAGRAMS article. If temperature displayed on scan tool is not as specified, 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 on scan tool is not -40°F (-40°C), go to next step.
  5. Turn ignition off. Access ECM below stereo, behind instrument panel, just in front of center console. On models with 4A/T transmission, disconnect ECM harness connector E8. See Figure. On models without 4A/T transmission, disconnect ECM harness connector E5. See Figure. On all models, turn ignition on. If temperature displayed on scan tool is -40°F (-40°C), repair short in wiring between ECT sensor and ECM. See WIRING DIAGRAMS article. If temperature displayed on scan tool is not -40°F (-40°C), replace ECM.
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