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Home >> Suzuki >> 2002 >> Esteem GL, 4D Sedan, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - 1.8L >> Diagnostic Tests >> DTC P0118: Engine Coolant Temperature Sensor Circuit - High Input >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. If engine system check has been performed, go to next step. If engine system check has not been performed, go to A4: ENGINE SYSTEM CHECK  under SYSTEM TESTS.
  2. Turn ignition on. Using scan tool, observe ECT parameter. If parameter reads -40°F (-40°C), go to next step. If parameter does not read -40°F (-40°C), problem is probably intermittent. System is okay at this time. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
  3. Turn ignition off. Disconnect ECT sensor No. 1 3-pin harness connector. ECT sensor is located in thermostat housing. See Figure . Check for poor terminal contact at ECT sensor connector. If poor terminal contact is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If no problem is found, leave harness connector disconnected and go to next step.
  4. Turn ignition on. Measure voltage between ground and ECT sensor harness connector terminal No. 1 (Light Green/Red wire). See WIRING DIAGRAMS article. Voltage should be 4-6 volts. If voltage is as specified, go to step  6 . If voltage is not as specified, check for poor connections in ECT circuits, also check for open or short to voltage in Light Green/Red wire between ECT sensor and ECM. If problem is found, repair as necessary. After repair, repeat DTC CONFIRMATION TEST  . If no problem is found, go to next step.
  5. Substitute a known good ECM, and repeat DTC CONFIRMATION TEST  . If DTC resets, go to next step. If DTC does not reset, testing is complete.
  6. Using a fused jumper wire, jumper together ECT sensor harness connector terminal No. 1 (Light Green/Red wire) and No. 3 (Orange wire). See WIRING DIAGRAMS article. Turn ignition on. On scan tool, observe ECT parameter. If parameter reads 401°F (205°C), replace ECT sensor. After repair, repeat DTC CONFIRMATION TEST  . If parameter is not 401°F (205°C), go to next step.
  7. Turn ignition off. Disconnect ECM 28-pin harness connector C20. ECM is located under instrument panel, behind glove box. See Figure . Check for poor, loose, corroded or damaged terminal connections in ECM harness connector C20. See Figure . If problem is found, repair as necessary. If no problem is found, substitute a known good ECM, and repeat DTC CONFIRMATION TEST  .
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