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Home >> Toyota >> 2001 >> RAV4 Base, AWD, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System Self-Diagnostics >> Diagnostic Tests >> DTC P0115: Engine Coolant Temperature Sensor Circuit >> Diagnosis & Repair
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Diagnosis & Repair

  1. Connect Toyota hand-held tester or scan tool to Data Link Connector (DLC) No. 3. See Figure. Turn ignition on and then turn hand-held tester or scan tool on.
  2. Using hand-held tester or scan tool, read engine coolant temperature for ECT sensor. If displayed engine coolant temperature is -40°F (-40°C), go to next step. If displayed engine coolant temperature is 284°F (140°C) or more, go to step  8. If displayed engine coolant temperature is same as actual engine coolant temperature, problem is intermittent. Check for defective connections or intermittent problem in wiring between ECT sensor and ECM. ECT sensor is located on coolant housing at flywheel end of cylinder head and contains Green 2-pin electrical connector with White and Brown wires. ECM is located behind passenger's side kick panel, just below instrument panel. See Figure.
  3. Turn ignition off. Disconnect electrical connector at ECT sensor. ECT sensor is located on coolant housing at flywheel end of cylinder head and contains Green 2-pin electrical connector with White and Brown wires. Connect jumper wire between both terminals on electrical connector for ECT sensor. Turn ignition on.
  4. Using hand-held tester or scan tool, read engine coolant temperature for ECT sensor. If displayed engine coolant temperature is less than 284°F (140°C), go to next step. If displayed engine coolant temperature is 284°F (140°C) or more, check for defective electrical connections at ECT sensor and electrical connector. If electrical connections are defective, repair as necessary. If electrical connections are okay, replace ECT sensor.
  5. Turn ignition off. Remove jumper wire. Remove glove box and passenger's side kick panel (if necessary) for access to ECM with electrical connectors still installed on ECM. See Figure. Ensure electrical connectors at ECM are securely installed so all terminals in electrical connectors are contacting terminals in ECM.
  6. Ensure electrical connector at ECT sensor is still disconnected. Connect jumper wire between terminal No. 18 (Brown wire) at ECM electrical connector E5 and No. 22 (White wire) at ECM electrical connector E4 with all electrical connectors installed on ECM. See Figure. This is the E2 and THW terminals on ECM.
  7. Turn ignition on. Using hand-held tester or scan tool, read engine coolant temperature for ECT sensor. If displayed engine coolant temperature is 284°F (140°C) or more, repair open Brown wire or White wire between ECT sensor and ECM. See WIRING DIAGRAMS article. If displayed engine coolant temperature is not 284°F (140°C) or more, replace ECM.
  8. Turn ignition off. Disconnect electrical connector at ECT sensor. ECT sensor is located on coolant housing at flywheel end of cylinder head and contains Green 2-pin electrical connector with White and Brown wires. Turn ignition on.
  9. Using hand-held tester or scan tool, read engine coolant temperature for ECT sensor. If displayed engine coolant temperature is not -40°F (-40°C), go to next step. If displayed engine coolant temperature is -40°F (-40°C), replace ECT sensor.
  10. Turn ignition off. Remove glove box and passenger's side kick panel (if necessary) for access to ECM with electrical connectors still installed on ECM. See Figure. Disconnect ECM electrical connectors E4 and E5. See Figure. Ensure electrical connector is still disconnected at ECT sensor.
  11. Turn ignition on. Using hand-held tester or scan tool, read engine coolant temperature for ECT sensor. If displayed engine coolant temperature is -40°F (-40°C), repair short in wiring harness and electrical connectors between ECT sensor and ECM. See WIRING DIAGRAMS article. If displayed engine coolant temperature is not -40°F (-40°C), replace ECM.
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