Exam 15: Temperature Sensors

An IAT is being tested. After the vehicle has been allowed to cool for several hours, a scan tool is used to observe the IAT sensor reading. When compared to the engine coolant temperature (ECT), the two temperatures should be within how many degrees F of each other?

Technician A says that the ECT and IAT sensors can be tested visually, as well as by using a digital multimeter or a scan tool. Technician B says that the ECT sensor is a high-authority sensor at engine startup and is used for open-loop control, as well as idle speed. Which technician is correct?

An exhaust gas recirculation (EGR) temperature sensor is used on ________.

The wiring to the IAT sensor has high resistance (cut wire). What could this cause?

Technician A says that the purpose of the intake air temperature (IAT) sensor is to provide the engine computer (PCM) with the temperature of the air entering the engine. Technician B says that the IAT sensor information is used for fuel control (adding or subtracting fuel) and spark timing, depending on the temperature of incoming air. Which technician is correct?

The sensor that measures the temperature of the air being drawn into the engine is called which of these?

Which of the following components provides the engine control computer with coolant temperature information?

All of the following are approved methods for diagnosing a ECT (engine coolant temperature) sensor EXCEPT ________.

In the below illustration what type of circuit is depicted?

A corroded connector at the ECT could cause ________.

Technician A says that other temperature sensors that operate like the ECT include the transmission fluid temperature (TFT), and cylinder head temperature sensor. Technician B says that all temperature sensors increase in resistance as the temperature decreases. Which technician is correct?

Why does the PCM monitor engine oil temperature on some vehicles?

Technician A says that all temperature sensors are PTC devices that decrease in resistance as the temperature increases. Technician B says that some vehicle manufacturers use a stepped ECT circuit inside the PCM to broaden the accuracy of the sensor. Which technician is correct?