Pcm Code E015, Open Coolant Sensor Circuit: Description

Coolant sensor is a 2-wire, variable thermistor. Signal voltage comes from PCM to sensor terminal "B" (circuit No. 410) and sensor reference ground to terminal "A" (circuit No. 1076).

As temperature of sensor decreases, sensor resistance increases. Signal voltage from PCM to terminal "B" increases as sensor temperature decreases and less current flows through sensor element to terminal "A" (sensor ground). PCM Code E015 sets because PCM assumes coolant temperature cannot be -36°F (-38°C) or less when MAT is 23°F (-5°C) or greater.