adding electric fan to TBSS, need help with tune

[Boost]

If that were correct, then could we somehow compare those two tunes to see what changes were made and then create a CAX file to do the same in EFILive? From what I have seen for the lean cruise CAX files, it then becomes a matter of knowing which memory address you want to change and what type of changes needed to be made (Hex address, number format, scaling, etc...)

+1
some clarity here would be great. If that's what Alvin did that is really cool on his part and helps him sell the fan parts. But I feel a little handicapped if we have to depend on competing software to get something simple and common like this done :(
(??)

[ScarabEpic22]

See the thing is the 08-09s didnt even have a PWM fan clutch, GM went to a purely mechanical setup for the last 2 years. So those OSs have no provisions for controlling fans at all...06-07s are fine, for a while the only way was to flash an 07 OS into an 08 TBSS.

A .cax would be awesome, but Id definitely want to make sure Alvin is ok with it first.

For those reading along, Im pretty sure the 06 and 07 TBSSs can control LS1 fans without needing any patching done to the ECM.

[Boost]

Yes I saw where the factory tune was controlling the STOCK ones, but have been too busy to read up on whether simply plugging the LS1 fans in (with the harness kit), the tune would still control them the same way?? Because that is what we are doing. And right now I am thinking we have to use the modified tune. Can anyone please clear this up? I looked at the modifed tune provided by them and it has a special table where you can select the TYPE of fan (discrete). So it looks like that's what one would use for non-factory fans. But I would really like to know how it works. Thanks

[minytrker]

If that were correct, then could we somehow compare those two tunes to see what changes were made and then create a CAX file to do the same in EFILive? From what I have seen for the lean cruise CAX files, it then becomes a matter of knowing which memory address you want to change and what type of changes needed to be made (Hex address, number format, scaling, etc...)

You wont see any differences with EFI.

[minytrker]

See the thing is the 08-09s didnt even have a PWM fan clutch, GM went to a purely mechanical setup for the last 2 years. So those OSs have no provisions for controlling fans at all...06-07s are fine, for a while the only way was to flash an 07 OS into an 08 TBSS.

A .cax would be awesome, but Id definitely want to make sure Alvin is ok with it first.

For those reading along, Im pretty sure the 06 and 07 TBSSs can control LS1 fans without needing any patching done to the ECM.

I will look back through the TBSS's I did. I was big into them a few years ago. I dont remember changing OS on the 08's with HPT, I thought it was just a patch but I could be wrong.

[ScarabEpic22]

It just a patch for the 08-09 now, initially people were experimenting with using an 07 OS to get the necessary controls. Its been figured out now using patched files.

[Boost]

Oh cool thanks. So basically, a "patch" is when they go in and add minor stuff as opposed to a custom OS?

[Boost]

Can anyone who has done this chime in? My friend was wondering about the best way to wire it up to the ECM.

[turbo_bu]

Yes I saw where the factory tune was controlling the STOCK ones, but have been too busy to read up on whether simply plugging the LS1 fans in (with the harness kit), the tune would still control them the same way?? Because that is what we are doing. And right now I am thinking we have to use the modified tune. Can anyone please clear this up? I looked at the modifed tune provided by them and it has a special table where you can select the TYPE of fan (discrete). So it looks like that's what one would use for non-factory fans. But I would really like to know how it works. Thanks

From my limited reading, the fan TYPE goes something like this: (note: I reserve the right to be more than slightly off on this one )

Discrete = relays. The fans are either on or off. You can do the 3 relay setup like F bodies to get a low speed / high speed thing, but basically the PCM is turning things on and off. NO modulation.

PWM Electric = pulse width modulation driving an electric fan (eFan). The PCM has a PWM driver that is being used to supply power to the fan. Maybe it is just sending power to an electrical driver ??? which then drives the fan?

PWM Electo Viscous = not sure on this one.

PWM Mechanical = engine drive fan (belt driven off of the accessories serpetine belt) with a PWM clutch to control engagement. This might be the option / patch that people are trying to get to work with the eFan options.

Anyone happen to know or want to guess if the patches that HPT's did were to get a PWM Electric option on a TBSS which had a PWM Mechanical to begin with?

[Boost]

http://www.pcmforless.com/install/fan/