[RC1488]

Originally Posted by Yajkwazo

I recently bought a 1999 Saturn SL2 with 111k miles on it. I didn't notice up until 3 days after the purchase that the Coolant tempature guage on the dash was always on "C", even after an hour running it. I was told to replace the Engine Coolant Temperature (ECT) Sensor, and I did so, with the note that I noticed corrosion on the electrical plug and sensor end. When I turned the car on, the guage was reading normal, or near the center. Then the Check Engine Light (CEL) came on. This was the first time that I'd seen the CEL, not before I switched the ECT sensor.
I took it to advanced auto and auto zone to get it checked out through a computer, on the way there, I noticed that the guage would drop, and I would raise RPM, like it would raise 1k RPMs and drop back to normal when the guage reads "normal"

The computer gave me these codes:
-P0118: ECT Sensor input above maximum acceptable voltage.
and these were listed as "pending codes":
-P0118: ECT Sensor input above maximum acceptable voltage.(again)
-P0125: Time it takes to enter closed-loop fuel control is excessive.

The employees there weren't any great help, and I disconnected the plug from the sensor and it still reads "normal" on the guage. I figured that maybe the plug is shorted, so I cut that off and it still reads "normal" on the guage. I took off the negative side of the battery and left it alone for 10 minutes. Hooked it back up and still got a check engine light. I have not checked the fuses yet because I really don't know what's the name of the fuse I should look for (saw two "coolant fan" fuses, nothing else that I noticed). I've drawn up that there may be a short somewhere, or I may have no clue as to what I'm doing. Please help me.

you replaced the Engine Coolant Temperture Sensor with a brass tipped one im assuming. Since there was corrosion on the connector, go to the junk yard and get a new one or get one from the dealer. splice/solder the new one in and you should be good to go. having corrosion on the connector is just as bad as having a cracked ECTS.