When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I recently bought a 2001 Monte Carlo SS I need the Check Engine light to turn off in order to get its emissions and registration done.
I took it to a local mechanic and they weren’t able to fix the issue. They replaced the current mass air flow sensor, camshaft sensor and fan control relays. Despite replacing all these parts , the check emhine light is still on.
I took it to Autozone and tested the engine to see which code it’s showing. PO481 Which is related to the cooling fan.
any tips on how to fix this issue would be appreciated. I’ve attached pictures as well.
I took it to a local mechanic and they weren’t able to fix the issue. They replaced the current mass air flow sensor, camshaft sensor and fan control relays. Despite replacing all these parts , the check emhine light is still on.
I took it to Autozone and tested the engine to see which code it’s showing. PO481 Which is related to the cooling fan
Was P0481 the only code originally or did the mechanic hose you by randomly replacing unrelated stuff?
What did they say when the repairs were complete and the light was still on? This just seems like a fairly simple code as there are only a handful of things involved to test so I'm a bit surprised they would just give up and hand it back (and if they did, I'd find another mechanic going forward).
How are you with electrical systems? Do you own a multimeter?
I'd test the relay first, even though its new. Wouldnt be the first one bad out of a box and IMO is the most common part of this system to fail. If that checks out good, I'd jumper the fan and make sure it works. If both of those test good, I'd take out the relay and jumper the fan on via the relay sockets. Thatll make sure the wiring from the fuse box to the fan is intact.
Beyond that it starts getting tricky - is it the wiring from the pcm to the relay? Bad pcm?
The PO481 code is what's currently showing after the other parts were replaced. I honestly didn't check the engine code, before the sensors and relays were replaced, so I'm hoping that the mechanic didn't rip me off He mentioned the current issue might be electrical, but it would take many hours to find the problem and there was no promise they could fix it. So i decided to leave the shop with the light still on.
As for the questions you're asking about the electrical systems, sadly it's a little above my head. I'm not experienced fixing cars. Do you live anywhere near Las Vegas, if so, can I hire you ? I will definitely be seeing a different mechanic this go around and am hoping they can fix, just wanted some advice on what i should tell them to look at. This information you provided seems helpful.
He mentioned the current issue might be electrical, but it would take many hours to find the problem and there was no promise they could fix it. So i decided to leave the shop with the light still on.
It's practically 100% certain that its electrical. Besides the actual fan blades, that whole system is electrical.
They're not wrong about the time part though. Like any issue, theres a diagnostic tree to go through from most to least likely. You might get lucky and its item 1, or you could get the flipside and its the 15th thing you check (exaggerating a bit here). That's the benefit of finding an experienced mechanic you trust is that they can quickly drill through the list rather than spending all day poking around burning up your money.
As for the questions you're asking about the electrical systems, sadly it's a little above my head. I'm not experienced fixing cars. Do you live anywhere near Las Vegas, if so, can I hire you ? I will definitely be seeing a different mechanic this go around and am hoping they can fix, just wanted some advice on what i should tell them to look at. This information you provided seems helpful.
I appreciate the offer, but i dont work on others cars anymore. I also rather dislike doing repair work on cars in general, lol. I'm more into the mod side of working on cars. Pretty cool you live in Vegas though, I love it out there. I live in PHX but try to get up there at least once a year for fun.
TBH, I'd put your research efforts more into finding the most reputable local shop for doing electrical work vs trying to get suggestions to help them diagnose. A lot of mechanics hate getting input from customers besides the symptoms. And really a good shop will have no problem figuring this out, it's a really simple system in the scheme of automotive electrical systems.
Check Engine (PO481)
He mentioned the current issue might be electrical, but it would take many hours to find the problem and there was no promise they could fix it. So i decided to leave the shop with the light still on. 
