Diagnostic Aids

Check for the following conditions:

• If DTCs P0115 and P0116 are both set the ECT sensor circuit may be open or shorted. Perform the DTC P0115 diagnostic table first.
• Check for the proper operation of the engines cooling system, including the correct coolant level.
• A faulty thermostat that stays open slightly can cause DTC P0116 to set in cold weather when the vehicle is started and let sit while warming up. Replace any suspect thermostat.
• Use the Temperature vs Resistance table in order to evaluate the possibility of a shifted ECT sensor. A shifted sensor could result in DTC P0116. Refer to Temperature Versus Resistance .
• Check for a faulty electrical connection to the PCM.

An intermittent malfunction may be caused by a fault in the ECT sensor electrical circuit. Inspect the wiring harness and components for an intermittent condition. Refer to Intermittent Conditions .

Repair any electrical circuit faults that were found. Refer to Wiring Repairs .

If DTC P0116 cannot be duplicated, the information included in the Freeze Frame data can be useful in determining the vehicle operating conditions when the DTC was first set.