2007 TrailBlazer Fan Settings for e-Fan Conversion

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05-22-2014
Just Chevy Trucks

2007 TrailBlazer Fan Settings for e-Fan Conversion

We're putting together a Stand Alone harness for a custom hot rod project. The 6.0 engine, harness and E67 ECM all came out of the same 2007 TrailBlazer. We're trying to change the fan setting to run 2 temp/AC controlled fans through a relay for each fan. I have done several Gen 4 harnesses from full size trucks and the fan settings were already correct and worked fine so I copied all the same setting into the TrailBlazer ECM figuring it would work the same. We tried to bench test the harness and haven't had any success, but I'm not sure if there may be other factors. One of the fan setting was that the fans won't operate until the engine has been running for 1 second. I changed this to 0 seconds. We "jumped the temp sensor wires to bump the temp up to the max 302 degrees, but the fan output wire won't energize. We can go in with VCM Suite and tell FAN 1 to turn on and the output wire energizes (grounds) correctly.

Am I overlooking something? Do I need to set something different in the ECM? Will it only work on a running engine and it can't be bench tested? Any input would be appreciated!
06-09-2014
kelleyperformance

so you have the two fan control wires already wired into the PCM, but just need help with what settings to change in the "system" tab under the fans?
06-09-2014
kelleyperformance

I am sorry I didn't see this sooner, and more sorry that no one helped you... as this isn't something that's too "tricky" for most active members on here. I love this forum for searching for info, but when you post a question... forget about it man. here is how you should set the fan settings:
First off, (obviously) we are under "System" > "Fans" : under 'Fan Type' change to 'Discrete'. next, under 'Number of Fans' change to '2'. next under "Startup Delay" change to "4". next under 'PWM Freq' change to '128hz'. Next, change the 'Run Time Max' to '0' sec (enabling this will cause the fans to run after the engine is off, every time- needed or not). the next table - 'Run Time' set to '0' all across. now in the two tables 'ECT Zone' and 'ECT Zone Hi' set them all at '304' across the board. next, set the 4 tables under these all to "304" in enable and "302" in disable. (these are all just to disable fans from coming on after ignition is off- they do not respond as an LS1 or LS2 tune would to the temps and times, so just leave them this way). next, 'fan %' to '42%' and 'fan hi' to '80%'.

now here is the main tables that will operate your "low" and "hi" fans. these are the settings I would use, as they seem to work perfect for us (we are in a hot climate). so under "fan desired %" - 'vs. ECT' apply '0' in the first cell (under 192*), next apply these numbers in order from the second cell (196*) to the sixth (210*) cell- 36,40,44,48,51; next, from cell seven (214*) to the last cell enter "100". here is what we have under the 'vs. a/c pressure' table- (from 1st cell to last cell) 0, 27, 31, 36, 40, 44, 48, 50, 51, 53, 54, 56, 80, 80, 80, 80, 80.

under "fan relay controls" - 'state vs. desired %' : (in order from top to bottom cell)- 36, 56, 100, 100, 100, 100, 100, 28, 48, 99, 99, 99, 99, 99. and finally, 'output control vs. state' is- 'fan output 1' - (left to right) 0, 1, 1, 1, 1, 1, 1, 1; 'fan output 2' - 0, 0, 1, 1, 1, 1, 1, 1; 'fan output 3' will be all ZERO / '0'. THATS IT you should have perfectly working fans that come on and off at ideal times
06-09-2014
kelleyperformance

oh and sorry about all that typing... I don't have any tunes or screen shots on this computer LOL. otherwise I would've just done that! good luck!
08-26-2016
Just Chevy Trucks

Quote:

Originally Posted by kelleyperformance

I am sorry I didn't see this sooner, and more sorry that no one helped you... as this isn't something that's too "tricky" for most active members on here. I love this forum for searching for info, but when you post a question... forget about it man. here is how you should set the fan settings:
First off, (obviously) we are under "System" > "Fans" : under 'Fan Type' change to 'Discrete'. next, under 'Number of Fans' change to '2'. next under "Startup Delay" change to "4". next under 'PWM Freq' change to '128hz'. Next, change the 'Run Time Max' to '0' sec (enabling this will cause the fans to run after the engine is off, every time- needed or not). the next table - 'Run Time' set to '0' all across. now in the two tables 'ECT Zone' and 'ECT Zone Hi' set them all at '304' across the board. next, set the 4 tables under these all to "304" in enable and "302" in disable. (these are all just to disable fans from coming on after ignition is off- they do not respond as an LS1 or LS2 tune would to the temps and times, so just leave them this way). next, 'fan %' to '42%' and 'fan hi' to '80%'.

now here is the main tables that will operate your "low" and "hi" fans. these are the settings I would use, as they seem to work perfect for us (we are in a hot climate). so under "fan desired %" - 'vs. ECT' apply '0' in the first cell (under 192*), next apply these numbers in order from the second cell (196*) to the sixth (210*) cell- 36,40,44,48,51; next, from cell seven (214*) to the last cell enter "100". here is what we have under the 'vs. a/c pressure' table- (from 1st cell to last cell) 0, 27, 31, 36, 40, 44, 48, 50, 51, 53, 54, 56, 80, 80, 80, 80, 80.

under "fan relay controls" - 'state vs. desired %' : (in order from top to bottom cell)- 36, 56, 100, 100, 100, 100, 100, 28, 48, 99, 99, 99, 99, 99. and finally, 'output control vs. state' is- 'fan output 1' - (left to right) 0, 1, 1, 1, 1, 1, 1, 1; 'fan output 2' - 0, 0, 1, 1, 1, 1, 1, 1; 'fan output 3' will be all ZERO / '0'. THATS IT you should have perfectly working fans that come on and off at ideal times

Thank you for sharing this information! It turns out the trick was that we needed to set the "State vs. Desired" for Fan 3 Output to the same settings as Fan 2 Output to actually get it to work.