E38 PWM fan help needed

[IMOR Kyle]

Hello, so I've been through the sticky on fans and spent a few hours searching the forum trying to find an answer on my own with no luck. I have a L99 out of an 11 Camero in a rock crawler project and I'm trying to get the fan set up to run PWM control using a C6 controller. ill attach a copy of the original tune and my current setup along with a log of a heat cycle. with current setup the fan desired % climbs with ECT as it should but I get no output from the PCM. Using a scope to monitor PWM output ECU connector 1 pin 58. If I put the original tune back in it it will bring the fan control circuit to ground. thinking maybe there is something i need o do with the state vs output or percent vs state charts but I cant find a known good file to look at. any help would be much appreciated, even if its just some guidance as to where i can find the correct training.
IMOR LJ updated.hpt
IMOR LJ.hpt
IMOR LJ fan.hpl

[blindsquirrel]

First thing I note is that 2011 Camaro (ahem...) and 2011 Corvette use different Service Number E38s, and having different Service Numbers means there are hardware differences inside, and not all Service Numbers are capable of doing the same output types. Personal example: a 2006 non-GTO E40 can do PWM EV at 2Hz, but outputs exactly nothing at PWM EV 100Hz. The GMPP E67s can do Discrete outputs just fine, but output exactly zero on PWM Electric. The little internal circuitry inside just is not arranged in a way that always works across all the possible settings.

Second, for a sample file use a 2011 Corvette 6.2 non-ZR1 (ZR1 is E67). Don't forget P0480, Fan 1 Control is set to MIL on Second Error. If you copy those settings and it doesn't work I would say it's a hardware limitation issue.

[blindsquirrel]

You can also try PWM EV instead of PWM Electric, there does not appear to be any real difference in the output logic between them but one might work where the other doesn't.

[IMOR Kyle]

Thanks for the info. I had no idea there are different versions of an E38, have a feeling I made an incorrect assumption that this was even possible. I just copied the corvette settings and I'm gonna give it try but I'm not optimistic...

[IMOR Kyle]

For the sake of conversation, is there any realistic possibility of upgrading to an ECU that is capable of PWM fan control and run the camaro (see I spelled it right this time) drivetrane. Or are my only options to use discrete control or go to a standalone fan controller. To clarify I do have access to GM MDI/Tech 2 for flashing a new/ blank ECU. Just don't have the experience to know what is possible and would rather ask than experiment and trash an ECU.

[blindsquirrel]

I don't know if the Camaro OS will run on the Corvette ECM hardware. Someone out there might know, one of the swap/harness specialists would know that kind of interchange info. They might even know specifics of what fan outputs each Service Number is capable of. Just because it's officially unsupported and not the way GM did it doesn't mean it won't work or there isn't a workaround.

There might also be a 'universal' replacement Service Number that can cover more applications than the original part did - GM has been known to do that sort of thing.

Have you tried all the variations available? PWM Electric+100Hz, PWM EV+100Hz, PWM EV+128Hz... It doesn't matter what the setting is called as long as it makes the fan go round and round, right?

[blindsquirrel]

Actually, after checking a different catalog source, '11 Corvette & '11 Camaro do both use ECM 12633238. So, um, never mind?

[IMOR Kyle]

Well sh=t... I did try PWM EV and MRF but not at 100, Ill give that a try after work today. Along with verifying that part number on the ECU I have.

[blindsquirrel]

I do have another thing in mind to try but you probably aren't going to like it. Turns out the Camaro & Corvette both use the same base OS, so a segment swap is possible...

[blindsquirrel]

rock crawler project

Man, why did I forget that part... segment swap should be no big deal since this is a swap. For whatever reason I was thinking it's still in a Camaro.

This is your file with the '11 Corvette 'System' segment swapped in, and all your System settings except for the fans copied over. Will require a write-entire (ECM only) with this file, if it doesn't work and you want to undo it will require another write-entire with one of your previous un-swapped files.

IMOR LJ - System segment swap.hpt

[Alvin]

You shoudl be able to jsut copy everything from the fan tab. We used to install these on trailblazer SS's all the time.

I'll warn you though, we stopped cause the fans and the connectors (even on OEM applications) burn up. The fan doesn't flow a lot either. I'd scrap that idea if you haven't gotten too far.

[IMOR Kyle]

Blindsquirrel, Worth a shot. I still really want to start by verifying the current service number.
Alvin, I currently have a tune in it with Corvette fan settings copied over and have nothing happening. we are using the C6 controller on a set of Spal brushless fans with all but the connector directly at the controller replaced with Deutsch connectors. Couldn't find a fan with internal PWM controller to fit our radiator properly. the packaging on this thing is pretty tight.
Current tune that doesn't work, lol
IMOR LJ updated.hpt
This is the project if anyone cares. Building with/for my dad. Started with a pile of tube a year and a half ago.
IMG_1204.JPG

[blindsquirrel]

The C6 module will not control a brushless fan. I thought all the Spal fans had their own controllers built in?

[IMOR Kyle]

Won't control them at all or is bad for the lifespan of one or the other? BTW your segment patch was the answer. I loaded it in and now have a valid PWM signal on the scope and two fans running at 30% as commanded by the VCM scanner. You are awesome!
edit: not sure anymore on the whole brushless thing. either way they work. spal VA11-AP7/C-57A

[blindsquirrel]

Yeah, those are plain 2-wire brushed fans. Brushless fans are 3-wire with the speed controller built-in.

Brushed fan, C6 module.png Brushless.png

[Alvin]

Good catch. yeah the C6 fan is brushed the controller will not run a brushless fan.

[IMOR Kyle]

So, fun story, actually got a little time today to take it out for a test drive, I guess I should say attempt to take it out. Trans is throwing a U0100 loss of communication with ECM. puts trans in limp mode. Flashed back in a file with everything the same besides the segment swap and the trans is back to normal. Compared files and as far as I can tell that is the only difference. Going to keep digging but thought I should update this thread as well.

[blindsquirrel]

Camaro/Corvette files have the same trans OS too so another segment swap is possible. Write-entiring the TCM is much less risky than the ECM, I'd start with only the TCM's System segment, copy back in any differences that result, and see what happens. Wish I knew for sure which segment handled the CAN comms but picking System wouldn't be a bad first guess.

[IMOR Kyle]

For reference, and for anyone that sees this through your other post, I'll attach current tune that makes trans work and the one that makes the fan work.

PWM fans work but trans sets U0100 and will not go into gear.
IMOR LJ 4-29 V2.hpt

Trans operates correctly but PWM fan control does not work.
IMOR LJ 4-29.hpt

[blindsquirrel]

Here's the file with both Corvette segments swapped.

IMOR LJ - ECM+TCM System segment swap.hpt

Doing a compare after the swap, there's zero editor settings different between before and after.