How to activate my efans 01 Silverado.

[Josh1500]

I'm converting my 01 Silverado 1500 to efans but need to activate them. They are wired to pin 42 blue and pin 33 red. How would I go about doing that, is it possible with my in tune?

[06MonteSS]

You can't.. would need to get a custom tune done in order to have the setting changed in the tune..

[MixManSC]

While the web site says you can control and adjust the efans on your 99-2004 model Silverado its very misleading. Definitely not something you can enable yourself. Someone would have to make a custom tune for you, and even at that I still do not know if they would then show up as one of the adjustable parameters. I asked this very same thing a week ago. Nothing but crickets in my thread..... http://diablosport.com/forum/viewtopic.php?f=44&t=49521

I'm doing this very same thing on my 99. Already have a set of LS1 (the smaller ones from a Camaro), the wiring I need, and even found a factory relay module from a newer 2006 Silverado so I can make it all nice and factory looking. Cannot install them yet though since I'll have no way to turn them on. Eventually I want to upgrade the alternator to a 145a from the stock 105a and swap in the larger 34" radiator and larger fans from a 2005+ Silverado as well instead of the smaller Camaro fans which have to be sort of cobbled onto the front of the radiator. The 2005+ setups bolt right on to our older trucks. On ours (99-02) the operating system on the PCM also needs to have the AC Recirc option set to Fan #2 instead of the recirculation door for true full PCM control. If you go that route you do lose the AC recirculation functionality though since the re-circulation door voltage reference wire is currently using pin 42 (I think its 42, I had to double check to be sure). I've already done a lot of looking into this myself. In my thread I also asked if I get a custom tune for example the 87 Octane one so I don't have to run premium gas, and I want to eventually sell the truck and put the stock tune back on will the fans then be dead or will the tune mod be enabled for all tunes (stock, 87, and the performance one)? If I'm converting it to efans it needs to be a permanent change across the board no matter the tune.

There are a few other options though. Temp sensor in the radiator, and secondary to the AC clutch power for each of the relays, manual switches to the relays, one of the aftermarket PWM controllers of which only a couple of the pricier ones have proven to have any sort of reliability like one from DCC, a very elegant solution from Dakota Digital - with 2 different modules from them you get exactly the same control the factory setup from a 2005+ will give you retaining your AC-recirc and not requiring any custom tuning and even shuts the fans down above 40 mph (the only other solution that will do that is going through the PCM for control), get someplace to mod the factory PCM tune (and hope then that the efan control parameters then show up on the Intune like they are supposed to), lastly go with a more do it yourself tuning setup like the HP Tuners VCM Suite in which case you can just do it all yourself. I'm thinking that last option is probably what I'm going to do.... since I'll have much more control, will be able to update the PCM to the latest operating system version, and much more. While its more expensive, I would be able to recoup a nice chunk of the cost by selling the Intune making it less of a financially painful option. I'm just hearing crickets in my thread on this. No answers, that is for sure. Having it just enabled in one tune would be pointless as that would essentially make the Intune a permanent part for the vehicle unless I want to indefinitely store the clutch fan and shroud to re-install them if I ever want to remove the custom tune.

[06MonteSS]

no you would not be able to adjust the fan settings via the tool...

and yes, you may be better off just getting an external controller for the fans...

[MixManSC]

Then Diablosport really needs to do something about this - this is for a 2000 Silverado. I'd personally say this is borderline false advertising..... It says this for 99 - 03 Silverado, Sierra, Tahoe, Suburban, Yukon, etc.... I'm pretty disappointed personally as its a very popular mod on these vehicles and part of what made me pull the trigger spending a couple hundred bucks on all the parts I'll need was thinking that I'd be able to actually adjust the fans.

[mikel]

If the vehicle is factory equipped with electric fans, the tool allows you to control them.
I do not see anything false about that advertising. If you add fans, we'd be more than willing to create a custom tune for you to enable them and allow the pcm to control them as if it were factory equipped, like we have done for countless other users.

Thanks

[Josh1500]

What do you need from me for that custom tune?

[mikel]

the tune files from the tunes folder on the intune drive.

[MixManSC]

I posted a thread about this very thing on the 14th. Even included the tune files (current and original backup) from mine and never got any response. Also had a couple of questions about how it works. Main question on this is that most anyone converting their truck to factory efans is doing so as a permanent change to the vehicle. If we reload the stock tune for something (even to sell the vehicle later) will the fans stop working with us potentially not even thinking about it, then driving down the road and overheating? Although with both the current tune and stock tune files included in the upload I'm guessing both could be modified? Another quick question in the same token - if I want to run the 93 octane tune for a bit, would the fans suddenly not be working on that one as well?

If the tunes can be modified at no (or minimal cost) to enable the electric fan functions in the PCM I'm great with that! I'd even take the time if needed to load each of the available tunes on my truck so each can be individually modified if needed so when I want to use one they will all be enabled. I realize though that it might not work like that. I don't want to be a complainer or anything. I had just expected that I'd see the fans option and had assumed it was something I'd be able to just adjust.

[mikel]

It is not a permanent change, the tunes must be installed for the changes to take effect, restoring the stock tune will put it back the way it came from GM.