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Code 3 (Coolant Thermo Sensor)

  1. Check for poor connections at coolant thermo sensor connector. Repair or replace as necessary. If connections are okay, check resistance of coolant thermo sensor. If resistance is within 94-73,800 ohms, go to next step. If not, replace coolant thermo sensor.
  2. Measure voltage at terminal "2I" of ECU. If reading is 12 volts, check for open circuit in wiring harness. If reading is zero volts, check for short circuit in wiring harness from coolant thermo sensor to terminal "2I" of ECU connector. If short is not located, replace faulty ECU.
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