My car throws codes, codes for back o2 sensor and knock sensor. I am N/A, so sensor must be bad. But wanted to know which one would cause my fan to run non-stop. I went to auto-zone, got the codes erased, fan went off, drove home and the CEL came on again, fan is on again?
Mine did that before. the check engine light came on and the fan came on too at the same time and I didn't have the AC on and the car was still cold.
Mine had a missfire on a cylinder because one spark plug was missing.
I just did a tune-up and the code never came back on again.
any CEL makes the fan run non stop. fix the problem get the code cleared and your fan will stop
Brandon Schmidt wrote:any CEL makes the fan run non stop. fix the problem get the code cleared and your fan will stop
Thats not true, I dont have a clue where you pulled that one out of.
Secondly the fan turns on when the car has hit a certain temp. It is turned on by the ECM, using the signal voltage from the ECT of how hot the car is. Now a ECT that is malfunctiong and saying the car is hotter than it is all the time, like it says 195F but it is actually 65F will make the fun run all the time.
As far as the O2 sensor code, normally it isnt the O2 sensor contrary to popular belief. The one way to check an O2 is using a scan tool check the crosscounts.
The O2 sensor is just syaing lean or rich whatever the case may be. So if it says O2 sensor lean bank 1, it means the car was running rich and the O2 sensor said rich go lean, and stayed there because you have another issue.
As far as the knock sensor code. What exactly was the code for that, low input, high input.
As with any sensor code the first thing to do is check to make sure one its pluigged in and two there isnt a bunch of corrosion build up on the connector. As lots of corrosion means high resistance and it means less current flow, thus why corrosion can cause a low voltage CEL to come on.
good luck
- 2004 Cavalier - 124k, owned since new
u stupid ass go make ur CEL come on the fan will come on
Brandon Schmidt wrote:u stupid ass go make ur CEL come on the fan will come on
Okay right now go to your car, lets see pull your IAT sensor? CEL came on, did the fan.......
- 2004 Cavalier - 124k, owned since new
YES IT DID MATTER OF FACT.. maybe its 95-99 but def ANY CEL makes fan come on. im sure someone can back it up
I have no clue, but one of the codes is making it do it.
have u had ur codes read? if not u need to start there.
Brandon Schmidt wrote:YES IT DID MATTER OF FACT.. maybe its 95-99 but def ANY CEL makes fan come on. im sure someone can back it up
I will back you up . I have no idea why GM has programmed it to come on for when a CEL comes on. Pos an audible indication to the owner something is amiss as in Crazy's case
My car didnt do it when I did it. But I unplug the ECT and it did, which makes sense.
- 2004 Cavalier - 124k, owned since new
My fan is staying on too. This happened after I did my intake, I think i must have dropped the IAT sensor, because its the only sensor that came on after i did the install. I think the car is getting an incorrect temperature reading of the air, or no reading.
codes read for the after cat o2 sensor, and knock sensor <but not sure what it said.
kiwicav wrote:Brandon Schmidt wrote:YES IT DID MATTER OF FACT.. maybe its 95-99 but def ANY CEL makes fan come on. im sure someone can back it up
I will back you up . I have no idea why GM has programmed it to come on for when a CEL comes on. Pos an audible indication to the owner something is amiss as in Crazy's case
makes sense to me, just in case something went wrong they dotn want your engine overheating too
