Plain Jane OEM nothing to see here rebuild

[JustJeff]

Originally Posted by Pete_89T2

The problem with doing it that way is your DVM/ohmmeter puts some voltage across the terminals you're trying to measure a resistance across. If it's still connected to the ECU with power applied you could potentially harm the ECU. Also, unless you have a good aftermarket temp gauge, how will you know the water temp when you're taking the resistance measurement?

Assuming you do have a temp gauge, one option would be to run the car until warmed up, then jot down the water temp off the gauge and shut it down. Disconnect the battery. Then disconnect the ECU connectors, and do your resistance measurement across the two ECU harness connector pins that connect to the water temp sensor. That will only get you one test sample though, so you still won't know if the temp sensor works across its full range. IIRC, the FSM gives 3~4 temp points to measure resistance on that temp sensor.

Yes I have an aftermarket temp gauge, a Prosport, which isn't name brand, but it' seems to be about dead on. The sender for the temp gauge is tapped into the front of the water pump housing and is taking a reading at the same spot the OEM thermosensor is.

I also have a temp gun I could point at the water pump housing, radiator, hose, etc.

I was thinking the same thing about taking multiple readings, per FSM. I could test as the engine is warming up. Turn off the engine at each temp test and continue to the next....ugh but that means taking the UIM off each time to get to the thermosensor harness.

Originally Posted by vrracing

Our RTek 2 shows the temperature reading from the ECU on the Palm. Does the 1.7 not have that capability?

No logging on Rtek till you get to 2

Originally Posted by JL1RX7

If its a RTD or resistance temp device it should have table somewhere about the resistance readings. So say 1k ohm means 72 degrees. Wouldn't really matter if you got multiple readings as long as you get a good resistance reading.

Also resistance will determine your voltage. So if your TPS has a "dead spot" it won't matter if you're reading voltage or resistance. One you when off, the when on.

The FSM has 3 temps to take resistances at and what the corresponding resistance should be, but not really a full scale that I know of. I suppose I could take resistance readings when they are at the resistances for a specific temp (per FSM) check the temp of the coolant to see if they line up.

With the TPS, yes we are kinda saying the same thing...I was more round about. But laws of electricity say that if there is a dead spot in voltage test there will be one for resistance also. I meant something is amiss, as in it wasn't tested correctly..not probed correctly and such.