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Home >> Toyota >> 2003 >> Matrix Base, FWD, Standard >> Repair and Diagnosis (Single Page) >> External Pages >> Different car >> Section 16 (Engine Control System Self-Diagnostics) >> Diagnostic Tests >> DTC P0116: Engine Coolant Temperature Sensor Circuit Range/Performance >> Diagnosis & Repair
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Diagnosis & Repair

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.
  1. Using Toyota hand-held tester or scan tool, check for any other DTCs. If only DTC P0116 exists, go to next step. If other DTCs exist, diagnose and repair those DTCs first and retest.
  2. Remove and inspect cooling system thermostat for damage and proper operation. Thermostat is located behind thermostat housing on passenger's side front of engine where upper radiator hose is attached. If thermostat is defective, replace thermostat. If thermostat is okay, replace ECT sensor. ECT sensor is located on passenger's side of coolant pipe at front of engine, in front of intake manifold and contains Black 2-pin electrical connector with Green/White and Green/Yellow wires. See ENGINE COOLANT TEMPERATURE SENSOR under ENGINE SENSORS & SWITCHES in REMOVAL, OVERHAUL & INSTALLATION - V6 & V8 article.
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