I rad somewhere that C4 Vettes had an oil temp sensor, is this true? Can it be used in my TA?

 

Yes, the LT1 Corvettes had a 3-wire oil temp sensor. There was a ground wire to pin B6 on the PCM, a signal wire to pin D26 on the PCM, and a signal wire to the instrument panel gauge. A lot of the pinouts on the C4 PCM are identical to the F-Body PCM, but whether there is anything in the F-Body PCM for the sensor to connect to is the question.

 

The vette LT1 has both analog and digital oil temp sensors. The analog simply connects straight to the analog gage, so you could use that easily.

Must be, since F/B PCMs work fine in the vette.

 

Sorry for dredging up such an old thread, but I really want to add the oil temp sensor to my car and was wondering if anyone knows the details for the pinout at the sensor side? And maybe the connector I need. I think its the same connector as the tps sensor but I'm not sure.

 

The Corvette 94/95 PCM schematic for the engine data sensors shows:

Oil Temperature Sensor Pins:

A - Black wire to PCM pin B6 (sensor ground). Splices together with grounds from CLT, TPS, EBCM and electronic transmission.

B - Dark green/white wire to pin D26 (engine oil temp sensor signal)

C - Dark green wire to instrument panel gage

 

Any idea which pins are which on the sensor? From what I can tell the pins are arranged like this
|
_ _

And I'm assuming are arranged
A
B C

But I have no idea...

The other thing I'm thinking is that with a multimeter I should be able to determine which pin is the ground, and I've got to assume the pcm signal and gauge signal pins are probably going to output the same resistance value at a given temp, so perhaps of those 2 it doesn't really matter which goes to the PCM and which goes to the gauge?

 

C connects internally to a resistor, which in turn is grounded to the shell of the sensor. A and B connect to opposite sides of what is shown as a variable resistor(thremistor). Not sure why the gage resistor is not shown as variable.

In the F-Body for example, the temp sensors (e.g. - coolant) for the PCM use a 5V reference, and the gages use a 12V reference.

 

I don't really know what to make of the reference values... Would I fry the PCM if I hooked up the 12v reference wire, or would it just return a nonsensical value?

 

When you hook up the two wires that go to the PCM, the PCM supplies the 5V reference signal. The variable resistance of the thermistor causes that voltage to vary, and the PCM interprets that voltage to determine the coolant temp.

The gauge portion of the sensor is totally independant, at least according to the schematic. In the case of the dash gage (GM spells it that way??) the gage supplies the 12V reference, and resulting voltage from the variable thermistor causes the gage needle to track the temperature.

You don't hook up any seperate voltage source to the oil temp sensor. You only hook up the three wires that I described.