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Home >> Dodge and Ram >> 1997 >> Caravan Base, 2.4 B >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 2.4L >> Trouble Code Tests >> Test TC-128A - Closed Loop Temperature Not Reached
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Test TC-128A - Closed Loop Temperature Not Reached

NOTE: For connector terminal IDENTIFICATION, see the CONNECTOR IDENTIFICATION DIRECTORY. For wiring diagram, see WIRING DIAGRAMS - 2.4L article.
  1. This test will be invalid if thermostat is stuck open. Diagnostic Trouble Code (DTC) may be stored in Powertrain Control Module (PCM) if engine temperature does not become greater than 50°F (10°C) within 13 minutes after engine is started. Possible causes are: defective thermostat, defective engine coolant temperature sensor, defective connector terminals or wiring, extremely cold ambient temperatures or defective PCM.
  2. Check that thermostat is operating correctly. If thermostat operates correctly, go to next step. If thermostat is not operating correctly, replace thermostat. Perform TEST VER-2A.
  3. Start engine and warm engine until engine coolant temperature is greater than 80°F (27°C). Shut engine off. Disconnect connector at engine coolant temperature sensor. Engine coolant temperature sensor is located near thermostat housing and contains Black/Light Blue and Tan/Black wires in the connector.
  4. Inspect connector for pushed out, miswired or damaged terminals. If terminals are pushed out, miswired or damaged, repair connector as necessary. Perform TEST VER-2A. If terminals are not pushed out, miswired or damaged, go to next step.
  5. Using ohmmeter, measure resistance between terminals on engine coolant temperature sensor. If resistance is less than 11,000 ohms, go to next step. If resistance is 11,000 ohms or more, replace engine coolant temperature sensor. Perform TEST VER-2A.
  6. Turn ignition off. Disconnect connectors from PCM. The PCM is located between driver's side front fender and power distribution center, near battery.
  7. Inspect connectors for pushed out, miswired or damaged terminals. If terminals are pushed out, miswired or damaged, repair connector as necessary. Perform TEST VER-2A. If terminals are not pushed out, miswired or damaged, replace PCM. Perform TEST VER-2A.
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