BMW 13621433076 Temperature Sensor Water/Oil

The ECT sensor is an NTC sensor that decreases resistance as coolant temperature rises. The ECM adjusts ignition timing and air/fuel mixture based on the engine coolant temperature, receiving a 5-volt reference voltage from the sensor, with the voltage drop varying as the temperature changes. If the ECT sensor input is faulty or implausible, the MIL illuminates, prompting the ECM to assume a substitute value of 80 degrees Celsius/176 degrees Fahrenheit to maintain engine operation, while setting ignition timing to a conservatively safe basic level. The ECT sensor is positioned below the cylinder 6 intake port at the rear of the engine, underneath the intake manifold. To access it, the intake manifold must be removed after ensuring the engine is fully cooled. The ECT sensor connector should be disconnected, and the sensor unscrewed from the cylinder head, with precautions taken to catch any small amount of coolant that may escape. Installation follows the reverse order of removal, requiring a new copper sealing washer for the sensor, replacement of any lost coolant, and checking and clearing fault codes from the ECM memory.