p0495 nightmare

changed ev fan clutch 2x - changed relay - replaced h20 pump, thermostat, radiator, coolant sensor etc.... still got the airplane taking off noise, crappy engine running, poor fuel mileage etc and the beat goes on.... help - btw also replaced engine side pigtail for wiring harness to clutch fan - there was a wire broken right past blade terminal sleeve and all the contacts were corroded. 5v reference is good no issues so im at my wits end..... HELP
 

TequilaWarrior

Well-Known Member
Any other codes? P0495 persist? If you can get a tablet/phone connected obd2 scanner (bluetooth and wifi are both available, though their models/makes escape me at the moment), look for current temp readings... high? Low? Trace wiring from fan clutch to PCM, all the way. I had a broken wire in the pigtail to the fan clutch that didn't throw a code and left my clutch engaged at all times, iirc. Does fan spin freely with engine off? "Airplane taking off" noise persist after engine at operating temp?
Also, how many drive cycles have you completed since replacing clutch? They will "lock up" sometimes, depending on their orientation when shutting the engine off. Mine does it every now and then - not often at all. I usually can shut the engine down, wait a minute and restart and it will be fine. Also, make sure your A/C is off.
 
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cobblershelli

Member
just constant 0495. temp readings normal - i already replaced pigtail due to broke wire... yes fan spins freely with engine off, airplane noise is constant. hasnt gone away since someone else changed first fanclutch....(i foolishly allowed someone else to work on my vehicle ) baaaaad idea.........havent traced wire back to pcm tho...so thats next inline when i get the vehicle back - daughter is using it cause her boyfriend screwed up his jeep by curbsiding control arm due to ice
 

TequilaWarrior

Well-Known Member
just constant 0495. temp readings normal - i already replaced pigtail due to broke wire... yes fan spins freely with engine off, airplane noise is constant. hasnt gone away since someone else changed first fanclutch....(i foolishly allowed someone else to work on my vehicle ) baaaaad idea.........havent traced wire back to pcm tho...so thats next inline when i get the vehicle back - daughter is using it cause her boyfriend screwed up his jeep by curbsiding control arm due to ice
Service manuals are available here. @Mooseman has them available in his sig. I'd be surprised if he didn't stop in soon.
When checking the wiring - ensure that the pins are in the right place at any plug that has recently been replaced. Is the pigtail new? I ended up repinning my pigtail and was ended up reinserting it into the wrong spot on the plug. It took me about a half an hour of troubleshooting after reinstalling it to figure that out. If your pigtail is new or came from a yard, who knows.
 
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cobblershelli

Member
pigtail is brand new generic non colorcoded - when i switched em over i wired each wire direct to corresponding wire on new pigtail set (which i had plugged into wire port on clutch fan side so i know that aint the problem. crimp tubed and shrink wrapped each wire separately all wires test out correctly at pigtail.

n its generic gm - straight from gmc dealer
 
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cobblershelli

Member
yep did that too - replaced both relays too... so theyre brand spankin new. i used an off brand apw i do believe

nope, scuse me got it from am autoparts.. idk branding but was off brand cheaper version
 

Matt

Silver Supporter
There may be the problem, Hayden is one of the only trusted brand for the fan.
 

Mooseman

Moderator
:iagree:

Another way you could get out of using the trouble prone electro-viscous clutch is to get your PCM tuned and use a thermal clutch from.a 2008 TB.
 
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cobblershelli

Member
I asked local stealerships bout that. The service writer dude 1) said ev clutch fan wasn't part of computer system for vehicle 2) after talking g to his head mechanic called me back. Apologized for #1 statement n said his mechanic said it wasn't done or necessary to do. Kinda gives me a lack of warm fuzzies when they don't know their (bleep) from a hole in the ground. I'll get hold of one in Frederick when I get that car back. Thanks
 

Mooseman

Moderator
That's because they won't/can't tune out stock stuff. You would have to take out your PCM and send it to be tuned. Otherwise, you're stuck using another EV clutch (Hayden, or ACDelco)
 
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cobblershelli

Member
I just wish it were financially feasible to go back to pre 81 vehicles with an engine compartment big enough to work in, with carbs, with vacuum operated switches, with mechanical pumps and WAAAAAY less wiring. . Engines were much more simple back in the day than they are now.. tracking electric gremlîns is s**t.

All that aside,. Mr. Mooseman, Where would or could I send PCM for reprogramming? Cause this is an avenue I am totally unfamiliar with.

I really do appreciate all yalls help Matt n Mooseman
 

Mooseman

Moderator
@limequat (lime-swap.com) is the one to.contact. $99 all included and a performance boost too. Talk to Jeremy for options.
 

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