Ok, I'm having some problems with this car and will be posting more for help on them. Car is a 94 SC2.

Here's the first one I'd like to tackle.

When you first start the car cold in the morning the cooling fan will run. This is with the A/C OFF. If the A/C were on it's supposed to do this but when the engine is cold and A/C is OFF this should not be happening. The interesting thing is the fan will shut off after about 5-6 minutes BUT it doesn't appear to want to turn on again. I let the car idle for quite awhile (with the A/C OFF) and the temp guage got close to the red and the fan did not come on. When I flip on the A/C the fan comes on as it should and the temp dropped immediately. Could this be the engine coolant temp sensor? If so is it located between the EGR valve and upper rad hose? I think that's it but unsure.

The water pump is new and so is the thermostat. Coolant level is full and the temp guage does work as it should

Thanks for any help

 

indeed sounds like ECTS -- two wire (not one wire) device sticking out of the head. Find EGR valve and look down at the head.

Replace connector too (dealer only)

 

Ok I just looked at it again and I see the two wire sensor down a bit further. Good that you pointed this out or I would have replaced the wrong one. Is this a "dry socket" or is coolant going to come out when I unscrew the sensor? Just want to be properly prepared.

What is the single wire sensor for? I'm assuming both sensors are the same part # correct?

Thanks much for your help! I'll update once i get all this replaced.

 

The two wire sensor is a "wet socket", so stand by with a rag, and do it when the engine is cold.

The single wire is for a different circuit entirely (also different part number)

 

single wire sensor drives the dash guage

2 wire sensor provides info to the PCM

(They had separate sensors up through 95)

 

Thanks for the help guys.

I figured they are each a different circuit but they look like identical so I was just curious what the other one did. The temp guage works fine so I'll leave the single wire sensor alone. Derf, I'll do as you recommend and also order a new connector for it.

I'm an Audi finatic and I maintain an older one for my driver and it has two sensors with the same part # but one is for the ECU and another for the idle stabilizer valve. Two identical parts with two completely different functions. My experience with this is what made me think the Saturn was perhaps similiar in this situation.

 

Update: Today I installed the new ECTS and connector and it fixed the fan problem. Hooray! Actually it fixed two problems. When you would put the car into park from drive the idle would shoot up to about 2K and then drop back down. After some searching on here I read that a bad ECTS can also cause high idle issues. It was nice to kill two birds with one stone. I received both parts from Saturn (GM dealer) and the connector they send is nice as it includes two heat shrink terminals and plenty of wire. The wires on the new connector are both white as opposed to the factory wiring which is black and yellow.

Again thanks for the help on this.