NEW
Font size
WorksheetsEngine Coolant temp sensor
Total questions: 31
Worksheet time: 16mins
What is the function of the component shown in the image?
To measure the temperature of the engine oil
To measure the temperature of the engine coolant
To control the engine ignition timing
To monitor the air intake temperature
What does the ECU stand for in the context of the diagram?
Electronic Control Unit
Engine Coolant Utilizer
Electrical Circuit Unit
Engine Combustion Unit
What is the purpose of the analogue to digital converter in the diagram?
To convert the sensor's digital signal to an analogue signal
To supply power to the engine coolant temperature sensor
To convert the sensor's analogue signal to a digital signal
To process the digital signal into actionable data
What is the function of an engine coolant temperature (ECT) sensor?
To monitor the temperature of the oil in the engine
To monitor the temperature of the coolant in the cooling system
To measure the speed of the engine
To control the fuel injection system
What does the cooling system do when an engine is running?
It adds heat to the engine block and the cylinder heads
It cools down the transmission fluid
It absorbs heat from the engine block and the cylinder heads
It lubricates the engine components
What does the ECT sensor monitor in an engine?
Oil pressure
Coolant temperature
Battery voltage
Exhaust gas composition
What is the function of the ECU in relation to the ECT sensor?
It controls the vehicle's audio system.
It monitors the vehicle's speed.
It uses the ECT sensor's information to determine engine temperature conditions.
It adjusts the seat positions.
Which of the following is NOT an input to the ECU according to the diagram?
Throttle position
Intake air temperature
Fuel injectors
Manifold air pressure
What does the ECU control based on the engine temperature?
The air conditioning system
The vehicle's navigation system
Fuel, ignition, and exhaust emissions
The entertainment system
Where is the ECT sensor located on some vehicles?
In the exhaust manifold
In an intake manifold
In the fuel tank
On the dashboard
Where is the ECT sensor located on other vehicles?
In the transmission
In the radiator
In a cylinder head
Under the vehicle
Why might an ECT sensor be deformed during fitting?
To reduce its lifespan
To make it look better
To give a better contact and temperature reading
To prevent it from working properly
What happens to the resistance of the ECT sensor as the temperature of the coolant increases?
The resistance increases
The resistance decreases
The resistance does not change
The resistance fluctuates unpredictably
What is the function of the ECU in the ECT Sensor Operation diagram?
To supply power to the sensor
To convert analogue signals to digital signals
To process the sensor's output signal
All of the above
What reference voltage does the ECU apply to the sensor circuit in the ECT Sensor Operation?
+3 V
+5 V
+12 V
+9 V
What happens to the voltage measured by the ECU as the sensor resistance changes?
It remains constant
It decreases
It increases
It changes
An ECU is monitoring the voltage signal from an ECT sensor on a running engine. What happens to the voltage signal as the engine warms up?
It increases
It decreases
It remains the same
It increases and decreases
An ECU is monitoring the voltage signal from an ECT sensor on a running engine. What happens to the voltage signal as the engine warms up?
It increases
It decreases
It remains the same
It increases and decreases
What does the analogue to digital converter do in the data processing system?
It amplifies the input voltage.
It changes the input voltage, +V, into digital data.
It reduces the input voltage to zero.
It stores the input voltage in a lookup table.
What is the purpose of the processing circuit in the data processing system?
To control the power supply to the ECU.
To convert digital data back to analogue signals.
To compare the data to values stored in lookup tables to determine coolant temperature.
To generate output signals for the engine.
How does the ECU use ECT sensor information?
To monitor the fuel level in the engine.
To control engine operation in either open loop or closed loop mode.
To adjust the vehicle's speed.
To change the digital data back to analogue signals.
What does the ECU use instead of actual sensor data during open loop operation before the engine reaches optimum operating temperature?
Feedback from the exhaust sensors
Pre-programmed data values stored in its memory
Real-time data from the fuel injectors
Manual input from the vehicle operator
What does a cold engine require at start up in open loop operation?
A lean mixture
A balanced mixture
A rich mixture
No mixture at all
What does the ECU control using pre-programmed data values in open loop operation?
The color of the engine light
The position of the idle air control valve and the length of the fuel injector pulses
The volume of the radio
The air conditioning levels
What mode does the ECU enter when an engine has reached operating temperature?
Open loop mode
Closed loop mode
Standby mode
Diagnostic mode
Which of the following sensors is NOT mentioned as being processed by the ECU for monitoring engine operation and emissions?
ECT
TPS
O2
RPM
What may prevent or delay an ECU from entering closed loop mode?
A defective battery
A defective ECT sensor or sensor circuit
Low engine oil
A faulty spark plug
What can be used to display live temperature data from the ECT sensor?
A multimeter
A scan tool
A voltmeter
A thermometer
Which of the following is NOT a symptom of an ECT sensor circuit problem?
Rich fuel mixture
Poor fuel economy
Engine stalling or difficulty starting
Increased exhaust emissions
Which of the following is a typical symptom of a defective ECT sensor or circuit?
Good fuel economy
Lean fuel mixture
Correct operation of emission control devices
Rich fuel mixture
What type of thermistor is most commonly fitted with ECT sensors?
PTC thermistor
NTC thermistor
RTD sensor
Thermocouple
