P1114

CIRCUIT DESCRIPTION
The Engine Coolant Temperature (ECT) sensor is a variable resistor, sometimes called a thermistor, that measures the temperature of the engine coolant. The Powertrain Control Module (PCM) supplies 5 volts to the ECT signal circuit. When the ECT is cold, the sensor resistance is high. When the ECT increases, the sensor resistance lowers. With high sensor resistance, the PCM detects a high voltage on the ECT signal circuit. With lower sensor resistance, the PCM detects a lower voltage on the ECT signal circuit. If the PCM detects an excessively low ECT signal voltage, which is a high temperature indication, this Diagnostic Trouble Code (DTC) will set.

CONDITIONS FOR RUNNING THE DTC
Engine run time is more than 5 seconds.

CONDITIONS FOR SETTING THE DTC
The PCM detects an intermittent high ECT sensor temperature while the engine is running and run time exceeds 5 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The MIL does not turn ON.
^ A DTC is stored in memory under history DTC.
^ The Failure Records are stored.
^ The Failure Records are updated after the first failure of each ignition cycle.
^ Some type C DTCs may also cause an auxiliary service lamp to be illuminated, and/or display a message to the vehicle operator.

CONDITIONS FOR CLEARING THE MIL/DTC
^ The history DTC will clear if the fault conditions have not been detected for 40 warm-up cycles.
^ A scan tool can be used to clear DTC information.

DIAGNOSTIC AIDS
^ An ECT sensor or PCM which is intermittently shorted, open, or skewed is possible, yet very unlikely.
^ An intermittent short to ground in the ECT sensor signal circuit could result in a DTC P1114. If the low ECT voltage reading is present, indicating a high temperature, additional sensor circuit voltage codes could be set. Refer to any non-intermittent DTCs that are set.
^ Use the Temperature vs Resistance Value scale in order to test the coolant sensor at various temperature levels in order to evaluate the possibility of a skewed sensor. A skewed sensor could result in poor driveability complaints. Refer to Temperature vs Resistance.
^ If an intermittent condition is suspected, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION

Steps 1-9:

The number below refers to the step number on the diagnostic table.
5. If there is no driveability complaint associated with DTC and it does not reset, then system OK.