Plain Jane OEM nothing to see here rebuild

[Pete_89T2]

Originally Posted by JustJeff

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.

Don't need to take the UIM off... What I was suggesting in my previous post is you take your readings off of the 2 water temp sensor pins on the ECU connector, after disconnecting it from the ECU. BTW, the resistance reading you'll get this way will be a little higher than what the FSM states for the temp sensor, but it shouldn't be by much more than a few ohms. This is because you're also measuring harness cable losses to the sensor.

[JustJeff]

Originally Posted by Pete_89T2

Don't need to take the UIM off... What I was suggesting in my previous post is you take your readings off of the 2 water temp sensor pins on the ECU connector, after disconnecting it from the ECU. BTW, the resistance reading you'll get this way will be a little higher than what the FSM states for the temp sensor, but it shouldn't be by much more than a few ohms. This is because you're also measuring harness cable losses to the sensor.

Forgive my ignorance, but I'm confused on how you're talking about testing resistance. IIRC the harness at the sensor is 2-pin. So to test resistance between those two pins wouldn't I need to find out which pin on the sensor harness corresponds to the ECU pin and then test resistance between that pin and the other pin on the sensor it'self?

I'm confused on what 2 pins on the ECU I'd be testing for resistance. 2E is the only water thermosensor pin on the harness/ECU. I originally was thinking I could put one DMM probe on that pin and one ground to chasis...but that's not the same as checking resistance at the sensor itself...or is it and I've simply overthought things and gotten myself confused.

For what it's worth, I was thinking the same thing about added resistance for the small load the harness will add.

[Pete_89T2]

Originally Posted by JustJeff

Forgive my ignorance, but I'm confused on how you're talking about testing resistance. IIRC the harness at the sensor is 2-pin. So to test resistance between those two pins wouldn't I need to find out which pin on the sensor harness corresponds to the ECU pin and then test resistance between that pin and the other pin on the sensor it'self?

I'm confused on what 2 pins on the ECU I'd be testing for resistance. 2E is the only water thermosensor pin on the harness/ECU. I originally was thinking I could put one DMM probe on that pin and one ground to chasis...but that's not the same as checking resistance at the sensor itself...or is it and I've simply overthought things and gotten myself confused.

For what it's worth, I was thinking the same thing about added resistance for the small load the harness will add.

My bad, I should have given you the reference to the schematic diagram on FSM page F2-8. If you follow the water thermo sensor wires back to the ECU connector on the diagram, you'll see you can measure your resistance between pins #2E and 3D. Pin 2E goes to the water thermo sensor and connects to nothing else; 3D is labeled "E2" on the ECU side, which I believe is a common +5VDC supply to a bunch of the sensors, including the water thermo.