'92 Temp Sensor

[FearlessFoe]

The last time I went to drive, I noticed my temp. sensor gauge wasn't working. I took the wire off and tested it, getting 5 volts. The sensor's resistance seems normal, a higher resistance at a lower temperature. Also, if I start the engine with the sensor unplugged, the service engine soon light comes on. I figured the signal is making it back to the ECM, but isn't making it to the gauge. Does anyone know where I should check?

[2000CAYukon]

The ECM temp sensor has nothing to do with the gauge. The temp sensor for the gauge is in the drivers side cylinder head. Make sure the wire did not come off the sensor; otherwise, the sensor may have gone bad or the gauge itself is not working (they can go bad).

//2000CAYukon

[Elbert]

on my 92K1500 the temp sesor in the intake maniforld tells the ECM the temp.
the sensor on the LH cylinder head "tells" the guage the temp.
I'm not sure which "sending unit" you looked at. The one in the cylinder head is the one to replace. Those year model trucks have problems with the guages too which are not repairable. I replaced my cluster with one out of a junkyard....now my guages work right. I think the sending in the cylinder head is about $25 or $35 depending on if you buy a GM one or not. Make sure to check for the correct style wiring connector on the end of the sending unit to make sure it mates correctly with the wiring harness, better yet take the old one out and carry it with you (first drain the coolant) or they are easy to swap out even without draing the coolant if you have the new one "in hand".

[FearlessFoe]

Alright.. I checked for the sensor and it was right above the exhaust manifold. My first thought was heat had finally killed the contacted or something by the sensor. I pulled the wire off and looked at it. There was only one contact (?) which was quite oxidized. Could someone please tell me how this sensor works? I need to know how to test to see if it is bad..

[maxwedge]

That is a temp sensor for the dash gage, temp sensor for the ecm is a 2 wire, usually in the int manifold. Wire off the dash gage reads low, grounded high, I believe.

[FearlessFoe]

Alright.. The sensor itself is a resistance type I believe. Do you know what voltage/resistance I should get when I test the wire?

[tdyer]

These sending units are not expensive, if you don't mind draining a little coolant. I'd recommend just replacing it. I recently replaced both sensors (ECM and Sending) on a friends truck. Her guage wasn't working. This fixed it.

[FearlessFoe]

Will do. Thanks