Deleting factory fan?

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,715
779
113
Texas!!!
are any of the stock fans electrically clutched or are they mechanical? i ask cause i see a setting for fans temps in hptuners for the lbz. and if so you could just use the clutch signal to run a relay to turn on electric fans.
No, they all use a thermo-viscous clutch.
 

turbhoe

researching lbz swap
Jan 8, 2011
141
0
0
jacksonville florida
then whats this table for? just wondering it seems like it applies progressive voltage to slowly engage the clutch.
fantemps.jpg
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
that table doesn't appear until 06 so that must be when it started.

The LBZ's and LMM's have the exact same viscous clutch as the LB7's and LLY's. Its not electronically controlled or electronically monitored.

HP Tuners has a lot left to be desired with duramax tuning. Who knows what that fan control table "actually" does, but I can tell you it doesnt control any fans. :)
 

turbhoe

researching lbz swap
Jan 8, 2011
141
0
0
jacksonville florida
The LBZ's and LMM's have the exact same viscous clutch as the LB7's and LLY's. Its not electronically controlled or electronically monitored.

HP Tuners has a lot left to be desired with duramax tuning. Who knows what that fan control table "actually" does, but I can tell you it doesnt control any fans. :)


ok from reading around, it looks like it may have suppose to have been there but gm didn't go through with it. so my next question is, does anybody know what pin in the pcm that table controls. if so and if its active then you can use that to control electric fans. like my tahoe, it didn't come with electric fans. but the pcm has the ability to control them. so you pin the correct spots and activate it in the tune and voila you have electric fan control. no need for controller that stick in the radiator.

but you are right the fan itself is not electric in any way.
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
ok from reading around, it looks like it may have suppose to have been there but gm didn't go through with it. so my next question is, does anybody know what pin in the pcm that table controls. if so and if its active then you can use that to control electric fans. like my tahoe, it didn't come with electric fans. but the pcm has the ability to control them. so you pin the correct spots and activate it in the tune and voila you have electric fan control. no need for controller that stick in the radiator.

but you are right the fan itself is not electric in any way.

Just because HPT has it in there doesnt mean its "right". They also have stuff in the TCM tunes labeled "line pressure", even though the allison doesnt have any form of electronically controlled line pressure.

Unlike the LS1 ECM in your tahoe, the bosch EDC16 on the LBZ wasnt used in any other applications, so there is no way to find out what pins would control an electric fan, if they even exist at all.

ben
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,686
5,840
113
Phoenix Az
05 trailerblazers use a thermo-electric fan as well but no dmax uses them. I see no provisions in efi live for the electric fan on a lbz.
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
13,715
779
113
Texas!!!
Does the lml use the same computer?
No, it's all new. I do seem to remember there being a fan control table in EFILive when it first came out, but I can't find it now. I wouldn't be surprised if the ECM has the capability to control an electronic fan clutch.
 

Darius6t9

I'm the Floater. Lurking.
Aug 23, 2008
574
0
0
Rusk, Tx. Again
Mine does the same thing. I figured that the fluid was just to thick in that cold of weather to let the fan spin freely. But, as General said, it doesn't ALWAYS do it.
 

turbhoe

researching lbz swap
Jan 8, 2011
141
0
0
jacksonville florida
LBZ/LMM uses a Bosch EDC-16c controller. LML uses a Bosch EDC-17

They are quite different unfortunately.


thats good to know i found: Engine Control Module (ECM): LMM 6.6L Diesel – Connector X-1 (continued)
Pin Wire Color Circuit No. Function
28 0.5 WH/BK 2366 Cooling Fan Clutch Control

i couldn't find a lbz pinout.
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
thats good to know i found: Engine Control Module (ECM): LMM 6.6L Diesel – Connector X-1 (continued)
Pin Wire Color Circuit No. Function
28 0.5 WH/BK 2366 Cooling Fan Clutch Control

i couldn't find a lbz pinout.

IIRC the medium-duty-only LMM's had an electronically controlled clutch. It was a PWM signal, not an "on/off" signal.