Diagnostic Aids

Check coolant level. Ensure thermostat and cooling fans are operating properly. Check for high resistance in wiring related to ECT sensor. Check for ECT sensor out of range by comparing actual coolant temperature with scan tool display, and replace ECT sensor if temperatures are not close. Check for faulty connections or damaged harness. If connections and harness appear okay, observe scan tool while moving all related harnesses and connectors. A change in scan tool display may indicate fault location.If DTC cannot be duplicated, FAILURE RECORDS data can be used in determining vehicle mileage since DTC was last set.