Recently got a trailblazer and it’s giving a check engine light for P1418 any idea on how to fix this what would need to be changed in order to get emissions done

 

The fan on the early ('03 & '04 IIRC) GMT360/370 trucks was engine driven, but computer controlled engagement. This code could mean there is a problem with the fan clutch or really anything that could interfere with actual fan speed as sensed by the clutch sensor. A few things that could cause the fan speed to be reduced include a faulty fan clutch and anything that could cause the fan to hit the shroud.(i.e. sagging/bad engine mounts, improperly installed shroud, shifted front end due to accident damage, etc). You could start by inspecting the clearance between the shroud and the fan. The fan should be centered. You can do the same with someone in the vehicle holding the brake while applying some throttle to apply load to the drivetrain; watch the motion of the engine with the transmission in both forward and reverse to see if it moves enough to make the fan hit the shroud. If that all checks out, then it likely is a failed/failing fan clutch in which case the fan assembly needs to be changed.

 

the fan and everything seems to be working and centered correctly in my opinion it’s going fast and doesn’t change speeds no matter how hot or cold it may get
thinking it might be needing a new fan clutch?

 

Does your scan tool have access to bi-directional controls? Do you or anyone that you know have a noncontact laser tachometer?

for the same one I purchased almost 7 years ago and use regularly.

With a scantool capable of bi-directional controls you can command a certain fan speed and then test that it is actually reaching that speed using a handheld tachometer.

But, since you indicated that the fan is not hitting anything, then the likely culprit is a faulty fan clutch.

 

I’m going to end up buying the fan clutch from a auto parts store near me and have one put in and if that fixes the issue then that is awesome, but if it fails I’m going to give what you mentioned a try. I truly do appreciate you responding to me. This is my first time owning a blazer let alone a Chevy I switched up from Japanese cars to this thought it was time for a switch lol. I’ll come in and post what my results are when I replace the fan clutch.

 

I replaced the fan clutch and still getting a check engine light oh no