I have been testing all of my sensors on my 3rd gen motor and I have noticed that when ever I turn on the ignition the resistance goes from a normal .68 to .11 ...... If anyone can tell me if this is normalor not it would help me grately....by the way I have been testing them at the ecu wire harnes and the other lead on a ground. by the way, the harnes is disconteced frome the ecu. thanks for any help..

 

usually the resistace is measured across the sensor

 

yes that is what I am doing just insted of at the sensor i am measuring it at where the ecu picks it up

 

yea but doing the ohms to ground instead of the other sensor wire will give a diff reading. the iat you are measuring the resistance across a variable resistor that changes with temp. the ecu sends 5 volts in and infers the temp by the return voltage across the resistance. you need to measure the sensor resistace not the sensors resistance through the chassis ground. you can do it that way disconnect the ecu plug and ohm the senor wire return signal and the 5volt ref wire and you will be doing the same thing

 

then why does one wire from the sensor go to the corisponding input on the ecu and the other goes to the grounds coming out of the ecu?

 

sorry....misunderstod.....thanks for the help

 

you cannot measure resistance accurately with voltage applied