After having the transmission replaced many years ago the temperature gauge in the car stopped working. I didn't take it back or anything and it's my fault for not doing so. I'm wanting to get it working again and did notice some hanging wires and a plug with no wires attached to it. I have attached a picture and hopefully someone can tell me what exactly this is for and where I can get one... I'm hoping this will get my temperature gauge working again. The location is right underneath the ignition distributor. The plug looks like it had two wires attached to it, but there are three loose wires... hmmmm... I can't reattach the wires because the plug is filled in and can only see the wire ends, no color is visible. Any help is greatly appreciated. It is a 92 civic sedan lx. 1.5L engine.

 

Under the distributor is located the 1-wire temperature gauge sending unit, which is for the dash temp gauge. The sending unit sits next to the 2-wire TW sensor that sends temp signals to the ECU. Is the CEL on?

 

Yes the CEL is on. The CEL didn't come on until recently though. The car only starts right up when it's warm. If it's cold out, it takes a while. The CEL used to go off after the car was warm, but now stays on all the time.

 

There are three wires though, I guess I will have to check tomorrow when it's daylight and see if I see the sending unit that has one wire. Maybe all three wires were cut off. Do you see the three wires in that picture?

 

It looks like your O2 sensor may not be plugged in either. That sensor is in the exhaust manifold on the front of the engine and has a lead that goes around to a plug above the transmission.

The plug you're holding in your hand is almost certainly for the TW sensor.

It is a lot easier to see when you remove the distributor temporarily. Be sure to mark it's adjustment position relative to the engine first. Then remove the 3 bolts and pull it straight out. You should be able to set it aside without unplugging anything.

 

Pull the CEL codes.

The sending unit connects to a Yel/Grn wire.

The TW sensor connects to a Red/Wht wire and Grn/Wht wire.

 

Thank you for the replies. I was able to see what two wires go to the plug I took out. You're correct, the red/white and the green/white go to that plug. I do have a yellow/green wire left and still cannot find where it goes to. I looked around underneath the distributor and near the tw sensor area, nothing. I'll look again. Also, I will check into the O2 sensor. Thank you very much!

 

Did you look at the diagram? Is the sending unit missing under the distributor?

 

Yeah, that's what I was looking for... the sending unit. I couldn't see it. I'll pull off the distributor tomorrow and see, maybe I'm just too blind.

 

Ok, thank you. It was next to the tw sensor like you said and how the diagram shows. All three wires have been hooked up and my temperature gauge is working like a charm now. Thank you. Now I have to figure out why the CEL light is on. The O2 sensor is intact. Could a failing fuel pump cause it to turn on?