1G Which Coolant temp sensor causes 21 code

[JBDdsmer610]

ok guys so i was driving my car the other night and I had my laptop hooked up and capturing a log with my link. I went back and looked at the log and noticed my internal temp was reading 97 degrees, and my factory gauge is right where its supposed to be and my aftermarket gauge was reading like 180. I'm just wondering if I could possibly have a bad coolant temp sensor since it was only reading 97 degrees. and it was prolly about 65-70 degrees out that night

 

[ErikTande]

Coolant temp sensor seems likely. A bad sensor can also make starting the car difficult. It's an easy swap and a cheap part, might as well change it.

 

[Nate355RS]

Sounds to me like you're logging coolant temp in celcius. 97*C = 206*F which is right in line with normal.

Usually when the coolant temp sensor goes bad it'll read super low, like -40* or around there IIRC.

 

[boostdawd]

Dumb question but u were looking at the coolant temp and not intake temp right. Double click the value and see the settings like Nate mentioned.

 

[JBDdsmer610]

ok guys I'm trying to figure out witch 2 wire sensor is the one that the ECU you reads my car is throwing a check engine light code 0021 coolant temp sensor circuit malfunction. Is it the two wire sensor on the top or the bottom the one that I need to replace ?

 

[gsxeclipse102]

Its on the bottom

 

[JBDdsmer610]

Thanks, i looked at that exact pic somewhere online don't know where but thats the pic i used for a refrence. I actually wasn't quite sure if i even ordered the right sensor but i did. when i would hook up my laptop to my car and connect to link and run a live stream my coolant temp was reading -74 degrees all the time it would never move. so when i actually went to put the new sensor in and match them up to make sure it was correct i started pulling back the boot around the wires connected to the sensor and noticed the orange wire on the bottom actually was broken off of the plug, so in the parts store parking lot i cut the factory plug off and put a female spade connector on each wire and then hooked them back up the car started right up and the CEL turned right off, and the car was deff running a lot better but now my regulator in my Alternator decided to crap out on me and the voltage dropped as low as 9 volts when i was driving it tonight but i was able to limp it home and just got it into a parking spot.