Engine/Transmission (1994 - 1998) Engine Coolant Temp Sensor missing, HELP

[DonTX]

My son has a pretty fancy code reader, we put it on and got several bad indicators. The biggest was a -40 reading on the coolant sensor. We scoured the manual and it claims there is a sensor behind the fuel filter, but it appears there is none there! Finally found the connector in the wiring harness for it, but it seems to be an open connector, and there is no "9 inch" jumper from that to the coolant temp sensor. We shorted it out and the code reader says it is hot.

I think I found the gauge sensor on the left rear corner of the head, but isn't there another for the PCM use? I have the factory manual and a Haynes, they don't seem to know either. What gives here?

 

[Dave M]

I'll attempt to post a pic of parts location in engine here. Looks like its at left side (drivers) of engine in the rear on head. There is a battery temp senser under drivers battery but I don't recall one for the PCM.

 

[Missouri Mule]

There is only one senosr for the coolant.

The 12 valves PCM does not control engine function so the PCM is not required to know what the engine is doing.

But I think that the data from the coolant sensor is sent to the PCM first then the PCM sends a signal to the tempature guage but I would have research that.



Looking at the connector that was connected to the coolant sensor it is on the small side. (Looked at it many years ago).

 

[DonTX]

I think I may have found the answer in searching this board. Apparently ONLY THE CALIFORNIA models had the "extra" sensor, therefore mine has only the plug in the wiring harness for making it a calif truck. Darned factory manual don't bother to say that, indicates ALL have a sensor there. The GAUGE sensor is in plain sight at the rear driver side of the head.

I am getting some more codes, but think the scanner is thinking gassers, it is not the nice Snap on that needs the VIN to make readings. I am suspecting my throttle position sensor is goofy too, trying to define its parameters.

 

[Missouri Mule]

The tempature sensor is wired directley into tempature guage.