P1115

CIRCUIT DESCRIPTION
The Engine Coolant Temperature (ECT) sensor is a thermistor, or variable resistor, that measures the temperature of the engine coolant. The Powertrain Control Module (PCM) supplies 5 volts to the ECT signal circuit through a pull-up resistor. When the engine coolant temperature is cold, the sensor resistance is high. When the engine coolant temperature 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 intermittently high ECT signal voltage (a low temperature indication), this Diagnostic Trouble Code (DTC) will set.

CONDITIONS FOR RUNNING THE DTC
^ DTCs P0112, P0113, P1111, or P1112 are not set.
^ The engine has been running for 60 seconds.
^ The Intake Air Temperature (IAT) is above -7°C (19°F).

CONDITIONS FOR SETTING THE DTC
^ The ECT sensor signal voltage is more than 4.9 volts. This would be approximately -21°C (-7°F).
^ The conditions exists for less than 1 second.

ACTION TAKEN WHEN THE DTC SETS
^ The control module stores the DTC information into memory when the diagnostic runs and fails.
^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.
^ The driver information center, if equipped, may display a message.

CONDITIONS FOR CLEARING THE DTC
^ A current DTC "Last Test Failed" clears when the diagnostic runs and passes.
^ A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
^ Use a scan tool in order to clear the DTC.

DIAGNOSTIC AIDS
If the condition is intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST

Steps 1-6: