Electric Fan always on

[Snap]

I am having an issue with my fan tuning on flat out shortly after engine start. probably reflecting the 5 second start-up delay value.

The scanner shows Fan Desired as 99.6%.

I have change the tune to single PWM Electric fan type and updated the Desired % vs ECT table. The minimum value is 89 deg Celsius at 11% so it doesn't make sense why it is turning on at 26 deg.

The a/c is off (actually not even charged at this point) so this shouldn't be influencing the fan cut in.

Any ideas why this is not working? or some settings to try? any ideas appreciated.

Tune: Holden L77 conversion.hpt

[hjtrbo]

These are the HSV settings for a VF2. Should be close to yours. See if anything stands out with a compare.

[Snap]

Thanks. This was helpful.

I didn't realise the R8 has a single fan.

I changed my Desired % vs ECT to match (the first few entries are 0's), but I still have the same behaviour. Any other ideas?

Maybe I need to do a support request.

[Jon S.]

The calibration attached in post #1 is partially set up for PWM fan control.

Are you using an add-on PWM fan controller (like a Corvette would have from the factory) ?

[hart-n-sol]

Having a similar issue with a swap recently completed. Subscribed for possible solution.

[Snap]

The calibration attached in post #1 is partially set up for PWM fan control.

Are you using an add-on PWM fan controller (like a Corvette would have from the factory) ?

In what way is the calibration incomplete?

I assume that the single PWM fan in the vehicle receiving the engine has its own fan controller. Wouldn't the E38 not drive the fan at all if there was no controller?

My issue is not that the fan isn't running, it's that it is always running regardless of the conditions.

[blindsquirrel]

Is the scanner reading zero for the AC pressure sensor as it should be with the system empty?

What fan controller hardware are you using? C6? Some aftermarket junk? What is it?? Is it a secret?

[hjtrbo]

The last thing I have for you to check is the following. Failing that my knowledge is at an ends.

Change the circled 25 to 0 and test please.

1.png

[Jon S.]

In what way is the calibration incomplete?

I assume that the single PWM fan in the vehicle receiving the engine has its own fan controller. Wouldn't the E38 not drive the fan at all if there was no controller?

My issue is not that the fan isn't running, it's that it is always running regardless of the conditions.

You never answered my question - are you using a PWM controller - somewhere between the ECM and the fan motor ?

Your 2011 Holden Commodore calibration (OS12639270) would have originally been setup to control the cooling fan(s) via standard automotive relays.

To have this OS interact with a PWM fan controller, requires more changes to the calibration than you made - and even then, it still may not work correctly depending on what is going on behind the scenes in your Holden OS.

So once again - are you using an add-on PWM fan controller ?

[Snap]

You never answered my question - are you using a PWM controller - somewhere between the ECM and the fan motor ?

Your 2011 Holden Commodore calibration (OS12639270) would have originally been setup to control the cooling fan(s) via standard automotive relays.

To have this OS interact with a PWM fan controller, requires more changes to the calibration than you made - and even then, it still may not work correctly depending on what is going on behind the scenes in your Holden OS.

So once again - are you using an add-on PWM fan controller ?

I thought I did answer your question by saying: "I assume that the single PWM fan in the vehicle receiving the engine has its own fan controller".

I was pretty sure that the fan controller was directly integrated with the fan (the original Holden Rodeo fan in the vehicle) given I was able to drive the fans when using the direct VCM Scanner controls. I was curious to understand exactly which calibration changes you thought were missed.

Is the scanner reading zero for the AC pressure sensor as it should be with the system empty?

This turned out to be my problem - thanks for the tip! When I ran the engine with A/C hoses not connected to the compressor (but with the pressure sensor connected to the hose) the reading was 0.00V / 0kpa. This was causing the fans to run continuously.

When I had the AC hoses made up and connected to the compressor (but without gas charge), the pressure reading became 48kpa and the fans started kicking in as configured. It seems the tables are ignored unless a pressure sensor reading (even if it is low) above 0 is being received. Fans now operate as expected and defined in the calibration.

Appreciate all the replys and tips. Hope this helps others.

Final tune file for reference: Holden SS L77 with single Holden Rodeo PWM fan.hpt

[blindsquirrel]

That's very Aussie-specific hardware, I'd guess the number of current users on this board who would be able to identify even the vehicles you're working with you could count on one hand and have a few fingers left over. You have no location under your username. Us USA-based guys don't have easy access to those service manuals even. And the vehicle the fan hardware is from didn't get mentioned until the last post - it would have been extremely helpful to put the car (truck?) year/make/model, and a wiring diagram for same, in the first post so people know what the hell you're talking about. We have no context and have to make wild guesses to even figure out what questions to ask.

[Snap]

That's very Aussie-specific hardware, I'd guess the number of current users on this board who would be able to identify even the vehicles you're working with you could count on one hand and have a few fingers left over. You have no location under your username. Us USA-based guys don't have easy access to those service manuals even. And the vehicle the fan hardware is from didn't get mentioned until the last post - it would have been extremely helpful to put the car (truck?) year/make/model, and a wiring diagram for same, in the first post so people know what the hell you're talking about. We have no context and have to make wild guesses to even figure out what questions to ask.

That's very fair feedback and thank you for helping me understand your perspective. I will adjust my profile and mention specific vehicle details next time. Appreciate your patients and help all the same.

[Hendocallum]

That's very fair feedback and thank you for helping me understand your perspective. I will adjust my profile and mention specific vehicle details next time. Appreciate your patients and help all the same.

Hi,
Did you end up sorting this problem out? Having the same issue with fan desired is always 99.6% regardless if ECT.

[Snap]

Hi,
Did you end up sorting this problem out? Having the same issue with fan desired is always 99.6% regardless if ECT.

Yes I did. You have to have the ac pressure sensor plugged into the wire harness and then the fan works like they should. Ac doesn?t need to be present/charged.

Let us know if this sorts your issue out too.

[LS ROB]

i'm having the same issue. fan starts running as soon as i start the car. AC is hooked up but is not charged. It may be possible i have wired it incorrectly as this is a swap vehicle with single fan and a trinary switch. Maybe i should check my connections...

[Snap]

i'm having the same issue. fan starts running as soon as i start the car. AC is hooked up but is not charged. It may be possible i have wired it incorrectly as this is a swap vehicle with single fan and a trinary switch. Maybe i should check my connections...

Yep same issue for me. Engine swap and now using a single fan. The Original vehicle the motor came from had dual fans.

If I Pull the ac sensor, the fans run flat out all the time. It appears the ecm fan logic needs an ac sensor reading.

[LS ROB]

what did you use for Hardware-Fan Type? im using "discrete." i wonder if i change that to "PWM electric" if it would make a difference?

[Snap]

what did you use for Hardware-Fan Type? im using "discrete." i wonder if i change that to "PWM electric" if it would make a difference?

That parameter depends on the fan controller /fan type you have. Ie controlled by PWM (variable) or by a relay (on/off).

Mine is PWM.
Fan type = pwm electric
Number of fans = 1

[LS ROB]

Thanks. Mine is wired into a relay.

[Snap]

Thanks. Mine is wired into a relay.

Discrete would be correct then.