I probably know the answer but I'll ask to be sure, I'm guessing I'll have to get updated tunes if I install e-fans on the truck, right?

 

i wouldn't think so. efans are mechanical and not controlled by the PCM, unless you have an 07+. but even then it shouldn't matter.

 

Eh, I'd say no.

 

This is a question where it would be great if one of the site's sponsors, who also sells electric fans and does custom tuning, adds a little input.

How many different add-on accessories require a new tune to be written?

Intake?
Exhaust?
Electric Fans?
Pulleys?

 

Pretty positive that for non forced induction with no internal engine work (i.e. cams, head work) or tranny work the tune is for the intake. The fans are controlled by a controller and work based on engine temp and preset or user set controller on/off temps and sometimes one may be activated by tapping the a/c compressor signal. Pulleys can be taken care of by bumping your idle rpms a little. I believe even most long tube header swaps don't need tuned for much less cat back type stuff. Most gears/tires are able to be taken care of with the handheld as well.

 

When I emailed Bill about this he said:

"Tuning for E-Fans involves basically raising the idle a bit to compensate for the increased load on the charging system."

Sounds like the same case as tuning for UD pulleys.

 

Why even do that? The fans only run when you're up to temp; usually when you're all warmed up, and you are driving as opposed to idling. I don't think that the electric fans draw enough electricity to drain your battery while you're idling.

 

Actually, they keep running when you are idling.?? The most noticeable side effect is that head lights dim and the fan blower will slow down with the lower output alternators at idle. An increase of just 50 rpms at idle helps.
I would not run out and get a tune just for the fans, hardly worth it.

 

Considering the PCM controls the alternator output...