yep thats right i officially have had my first check engine light on my ecotec.... all this started after i installed my system... i dont know if it has anything to do with the light or what but heres the problem.... ok when i installed my system i added another ground frrom the top post of my yellow top battery to my strut tower you know just to add a extra ground.... well a week or so later my check engine light comes on and its the IAT sensor. i cant recall the number of the code but it says IAT sensor high input.... ok i have had autozone delete the code 3 times already... strange thing is the light comes on every 3-4 days, i have autozone delete it and it doesnt come on again for another 3-4 days.... i dont know whats going on with this...... ok i have had this car since october of last year and the IAT sensor plug has had a new connector installed because the connector has been spliced onto the stock wire.... my question is could this connector be messing up or do you think the sensor could maybe be bad..... i dont think the system install had anything to do with this........ what does everyone think about this...... please help me asap this is getting annoying already......

First off what year is your car, and how many miles, just wondering cause I have an 04 and hearing about problems with 04s kind of worries me.

Anyways the computer is monitoring every sensors voltage all the time. If the sensors voltage goes to far above or below a specified limit the CEL will come on.




- 2004 Cavalier - 124k, owned since new

i have a 2002 cavalier with the 2.2 ecotec with 79k miles

check the wiring going into the sensor. one of the wires on the harness may be broke

i just find it odd that it works for a few days then comes on, i turn it off, then it stays off for a few days.... then it comes back on..... i just think thats odd....

anyone else have any ideas? i am going to replace the sensor tomorrow so i hope it helps....

check the wires going to the sensor. i had a coolant problem w/ a sensor and my check engine light would come on sometimes when it was hot out. never came on once during the winter and it randomly came on when it was warm out. so being urs comes on every few days isnt that weird.

importfightercavalier wrote:i just find it odd that it works for a few days then comes on, i turn it off, then it stays off for a few days.... then it comes back on..... i just think thats odd....

the reason it takes 2-3 days to reset is when u clear the codes the computer is put into what they call not ready mode that means u have to putt several miles on the car before it picks up the code.Also the code is not a hard code witch means it's not something that will do damage or it is not so serious. I would check the wires and make sure you soldier the wires and use plenty of electrical tape. If you get the code i can get a pinpoint test for u.

Also check the terminals inside the connector and see if they are spread open.

the normal problem is the wire breaks just as it goes into the connector , if you lightly pull on the wires , 1 will usually pop right out

other thing would be to swap a sensor with a friends car

well i went to the dealer and got a new sensor, installed it and cleared the code..... it was off for a few hours then all of a sudden came on lastnight.... well i went home and woke up this morning and started the car and the light was off.... and has been off all day long so we will see how it goes..... freakin OBD2 system i hate when my cel is on LOL.....

well now the light is on and has been on for weeks now i am going to try and fix the wires if that doesnt work i am going to give up... anyone else have any ideas? does it matter which wire goes to whicih on the connector? the wires are solid white and the wires for the sendor from the ecm are red and black i believe. HELP ME...

same thing happend to me and one of the wires was broken so i bought a new harness from GM and it fixed the problem

how long was the wires? where did you have to trace the wires to? hopefully it doesnt have to go all the way to the ecm.....

also on the new harness did it have colored wires or just white? if it has just white does it matter which wires connect to which?

well i redid the wires, went to autozone and cleared the code and it hasnt came back on since yesturday.. i am so happy that the car is running like it use to.. when the check engine light was on it ran like poo.. now i got my power back .. thanks guys...