Temperature sending unit-sensor
#1
Temperature sending unit-sensor
Does anyone know how to test the temperature gauge sending unit /sensor. The sensor with one wire going to it ? Not the coolant sensor next to the time switch. 22re motor
#5
91 22re motor.
My senders ohms increase as the sender cools down.
As the sender warms up the ohms drop
Here is what I tested my sender at, not sure if it is working correctly
.500k ohms at 70'f
400 ohms at 130'f
My senders ohms increase as the sender cools down.
As the sender warms up the ohms drop
Here is what I tested my sender at, not sure if it is working correctly
.500k ohms at 70'f
400 ohms at 130'f
#6
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0.500k ohms is the same as 500 ohms. Which is not much of a difference from 400 ohms.
The temperature curve for the ECT sensor is shown here: http://personal.utulsa.edu/~nathan-b...98engineco.pdf This is the characteristic curve for an NTC (negative temperature coefficient) resistor. I'd like to say that all NTC resistors have the same values, but they don't. Would Toyota use the same parts in all of the temp sensors? Maybe, except the ECT sensor is a two wire device and the gauge sensor is a one-wire, so I'm not going to make that leap.
Note that the ECT sensor should be about 500 ohms at 130°F, and 2000 ohms at 70°F.
The temperature curve for the ECT sensor is shown here: http://personal.utulsa.edu/~nathan-b...98engineco.pdf This is the characteristic curve for an NTC (negative temperature coefficient) resistor. I'd like to say that all NTC resistors have the same values, but they don't. Would Toyota use the same parts in all of the temp sensors? Maybe, except the ECT sensor is a two wire device and the gauge sensor is a one-wire, so I'm not going to make that leap.
Note that the ECT sensor should be about 500 ohms at 130°F, and 2000 ohms at 70°F.
#7
I wonder why my meter reads it at .500k ohms....I put a 500 ohm resistor across my test leads and the meter reads 500 ohms, but when I put the temperature sender across it, it reads .500k ohms and 500 ohms like it should.
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Do you have an auto-ranging meter (many today are). http://www.autoshop101.com/forms/h4.pdf
.5k and 500 are both correct readings; you just have the meter set on a different range.
.5k and 500 are both correct readings; you just have the meter set on a different range.
#11
I tested the old sender..and it was within spec, but then suddenly decreased after reaching a certain ohm.
I went ahead and found a new sender at autozone..and it works fine now...Thanks for the help.
I went ahead and found a new sender at autozone..and it works fine now...Thanks for the help.
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my 87 22re has 2 orange look like reset buttons on the top. they about the thickness of your thumb nail, pushed them back in but i already changed it out so don,t know what they did.
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