What are the normal values of resistance and voltage for an automotive water temperature sensor?

Where is the engine water temperature sensor

The location is different for different engines, most cars are at the rear of the cylinder head where the thermostat is, down the top hose to the head fitting is the thermostat and the water temp sensor is in that location.

Strictly speaking water temperature sensors fall into two main categories. Whichever one it is the internal structure of the Thermistor Its resistance value is between 275 ohms and 6500 ohms. And the lower the temperature the higher the resistance value, the higher the temperature the lower the resistance value.

Water temperature and water level sensor consists of a thermostat part and a water level control part, with its supporting and motorized valve before the decompression device, and for the heating of the rotary muffler heater. The role of the water temperature sensor is to convert the cooling water temperature into an electrical signal, the input ECU has: correction of the amount of fuel injection; when the low temperature increases the amount of fuel injection. Correct the ignition advance angle; increase the ignition advance angle at low temperatures and delay it at high temperatures to prevent deflagration. Affects the idle control valve; at low temperatures the ECU controls the idle control valve action according to the water temperature sensing signal and raises the speed of rotation. Affects the EGR valve.

What are the normal values for the resistance and voltage of the water temperature sensor in a car engine?

There are two main types of water temperature sensors. Whichever it is, its internal structure is a thermistor, and its resistance value is between ohms and ohms. And the lower the temperature the higher the resistance value, the higher the temperature the lower the resistance value. The role of the first type of water temperature sensor is relatively simple is through its internal resistance changes to achieve through the sensor resistance changes to change the current through the changes to drive the water temperature table changes, indirectly tell people the engine operating temperature. The second category, the water temperature sensor from the structure of no change, but its role is to provide a temperature change to the engine control unit analog. Its supply voltage is provided by the control unit 5 power supply, return to the control unit for 1.3-3.8 linear change. The main role is to tell the engine control unit how much the current temperature. In turn, it is important for the control unit and its. The main thing is that the engine has different working methods at different operating temperatures.

1、Measurement of resistance (multimeter resistance, ECU power off during measurement)

NE Sensor (40 to 41): 120 to 125Ω

PCV1, PCV2 solenoid valve (two pins on valve): 3.2Ω

Injector (solenoid valve two pins): 0.9～1.1Ω

The resistance of the three sensors is the same for the outlet temperature (155 vs. 55), the intake temperature (32 vs. 55), and the return temperature (162 vs. 55).

2、Measurement of voltage (multimeter DC voltage)

G Sensor (120 vs. 131 pins): 0.9V during engine operation

Common Rail Pressure Sensor (121 vs. 134): 650rpm 44 Mpa 1.72V, 2370rpm 103 Mpa 2.70V

Accelerator Pedal (Heavy Duty Williams): APP1 (21 vs. 135): Open 0%: 0.75V, 100%: 3.84V

APP2 (22 vs. 136): Open 0%: 0.375V 100%: 1.92V

Accelerator Pedal (XU CHUNG HIS): APP1 (21 to 135): Open 0%: 0.85V 100%: 4.15V

APP2 (22 vs. 136): Open 0%: 0.85V 100%: 4.15V

3、Voltage value in case of engine sensor failure (open signal wire, short to power, short to ground):

3.1 The three sensors for outlet temperature (155 vs. 55), intake temperature (32 vs. 55), and return temperature (162 vs. 55) have the same voltage values when they are faulty:

Sensor AD Open signal line open: 4.88V, Vcc Short to power: 4.88V, GND Short to ground: 0.02V

3.2 Accelerator pedal (21 vs. 135), (22 vs. 136) and PTO potentiometer (or car hoist on-board throttle):

Sensor AD Open signal line open: 0.18V, Vcc Short to power short: 4.88V, GND Short to ground short: 0.02V

4、Intake pressure sensor:

Sensor AD Open signal line open: 0.07V, Vcc Short to power short: 4.88V, GND Short to ground short: 0.02V