EVO ecu in 1st gen./cooling fans

[JamiesTSI]

Do they make a lower temp. sensor for the radiator? (To turn the fans on.)

Or could I use the evo ecu, I believe pin #21 with a relay to control the fans? It looks like the #21 pin goes high(resistance) when you activate it with Evoscan.

Would it be possible to power the coil, on the relay, full time. Then when the engine calls for the fans, to drop the ground(high resistance) on the coil which would then provide power to the fans via the relay contacts?

Thanks.

 

[rlacasse1]

In all honesty, you should ask the people on Evolutionm.com

They have a lot more info on their site than there is on this site regarding an EVO ECU in a 1g. Look for a guy named OxDead, he has a ton of info on the swap.

 

[steve]

Or could I use the evo ecu, I believe pin #21 with a relay to control the fans? It looks like the #21 pin goes high(resistance) when you activate it with Evoscan.

Would it be possible to power the coil, on the relay, full time. Then when the engine calls for the fans, to drop the ground(high resistance) on the coil which would then provide power to the fans via the relay contacts?

Thanks.

I haven't looks at how it's done on an EVO but on a 2G the ECU ground the relay coil to activate the fan. If you put this relay in place of the thermoswitch on a 1G the ECU could activate the fan.

 

[mike96]

I haven't looks at how it's done on an EVO but on a 2G the ECU ground the relay coil to activate the fan. If you put this relay in place of the thermoswitch on a 1G the ECU could activate the fan.

evo is kind of the same way. difference is that the evo ecu actually puts out a PWM signal that is suppose to go to a fan control module..... however, us guys using the evo8 ecu in our 2G's have them wired directly into the 2G factory wiring without any big issues. so at worse i would say wire your 1G fans similar to a 2G and you should be fine.

or wire them like steve mentioned. you can probably use a GM fan temp switch instead of the factory Mitsubishi one. i have seen them go as low as 160 deg, those are special order but most places like checkers or autozone should have 180 or 170 deg switches.

 

[steve]

If the output is PWM I wouldn't feed that to a relay. Only if someone has modded the code to just switch on and off.

 

[danl]

The stock evo has a cooling fan controller that can vary fan speed with PWM so you would need to use that to drive your fan. Or you can change the table to be 0 or 100 and no 50% so that it won't cycle your relay and you can then use that output and control the temperature it turns the fans on via the ecu. FYI I am 0xDEAD on evom.

 

[rlacasse1]

Haha awesome. i'm the guy that was PMing you for the info on it and asking all the questions. Unless a lot of people do that.

 

[mike96]

The stock evo has a cooling fan controller that can vary fan speed with PWM so you would need to use that to drive your fan. Or you can change the table to be 0 or 100 and no 50% so that it won't cycle your relay and you can then use that output and control the temperature it turns the fans on via the ecu. FYI I am 0xDEAD on evom.

i don’t remember having read anywhere in the forum where anyone has made any recommendations to change to the tables when running the eclipse fans with the EVO8 ecu. so far i have had my eclipse running for almost 8 months before it got totaled and i don’t recall anyone else having any other issues with the fans. suppose it is something we can keep an eye out for though. feeding a PWM signal through a standard relay... worse case happens would be the ECU going titt’s up, but i imagine that the relay will go before then. something to keep an eye on i guess.

 

[danl]

The ecu won't give a shit, the relay will.......

I should add that if the 2g has the relay activated via the ecu then the relay is probably spec'd to operate with PWM. The 1g's do not operate like this from the factory, so running the stock relay at 40% duty will kill it.

This really isn't hard guys. Figure out how you want to activate your fan and run the proper relay or controller.

 

[steve]

TI should add that if the 2g has the relay activated via the ecu then the relay is probably spec'd to operate with PWM.

The 2G doesn't do any PWM on the fans that I know of. The ECU has two speed relays, high and low and they're either on or off, depending on the vehicle speed, ECT and A/C switch.

 

[Ceddy]

Only the Solenoids, O2 Heaters, and Boost Gauge are PWM on the 2Gs. The Fans are either on or off.

Having an Evo ecu PWM output connected to a relay probably isn't the best thing for the relay or ecu.

 

[JamiesTSI]

Danl:

Do you have or know of a definition or address(fan control) for the 9653 rom?

I have a couple feelers out on Evom to some of the gurus, have not heard back from them yet.

 

[danl]

I am not seeing it in my rom. I have an evo 9 and it has a fan controller. I believe the evo 8 is the same way. Thus the evo 8 code is probably doing some PWM to the relay but it isn't defined as of yet.

 

[knochgoon24]

Only the Solenoids, O2 Heaters, and Boost Gauge are PWM on the 2Gs. The Fans are either on or off.

Having an Evo ecu PWM output connected to a relay probably isn't the best thing for the relay or ecu.

So should those of us with the Evo ecu in our 2g's change the fan control maps to just 100's and 0's?

 

[mike96]

i might have it. let me look in my definition when i get home. i vaguely remember having that table... it has been a while since the last time i messed with my evo rom.

 

[Ceddy]

So should those of us with the Evo ecu in our 2g's change the fan control maps to just 100's and 0's?

Yeah, that would be a good idea. The PWM frequency is fast enough (~100 Hz) that the relay won't cycle will the frequency. But at less then 100% DC the coil is going to see a voltage lower then it was designed for. This may lead to the coil burning up faster.

 

[JamiesTSI]

Found this on Evom evolutionm.net - View Single Post - Found Thermo Fan Switch Conditions was wondering if this might be another way to control fans.

A member on Evom(Logic) said the 9417 and 9653 have the same addresses. I patched my rom with it and was able to get values.

I'm wondering if the values are set-up the right way if it would be possible to switch a relay to control the fans. The evo ecu has 4 AC pins, I need to find out if one of them switch high or low. Anybody have thoughts?

 

[knochgoon24]

Hmmm.... I just added those tables to my ROM. I'm not sure the values that are showing make sense though.

From the EvoM link:

First map i call "AC Fan low Duty" it has two duty values and it controls the ac fan. Based on the duty values of the main fan.

Then we have "AC Fan" values: Vehicle speed, Engine rpm and Coolant temperatur.
They control when the AC fan comes on (don't know if high or low. Or even olny switch from low to high.).

Then two "Main Fan" values one for throttle position and one for coolant temp.

And there is a "Fan counter" i don't know what it does.

AC Fan Low Duty
Off -> Low 0.0%
Low -> High 37.5%

AC Fan High Speed
On 199mph
Off 159mph

AC Fan High rpm
On 7969rpm
Off 7969rpm

AC Fan High Coolant
On 419 °F
Off 419 °F

AC Main Coolant
On 149 °F
Off 158 °F

AC Main TPS
On 78 %
Off 82%

Fan Counter
0x0000

The values don't seem correct to me. ???

 

[knochgoon24]

Well the 2 other Thermo fan control table addresses from 94170015 don't work for 96530006, so now I'm even more confused.

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<table name="Thermo Fan Duty" category="Miscellaneous" address="459a" type="3D" level="2" swapxy="true" scaling="Percent (128)">
		<table name="Conditions" address="67f8" type="Static X Axis" elements="9">
			<data>On1</data>
			<data>On2</data>
			<data>On3</data>
			<data>Off1</data>
			<data>Off2</data>
			<data>Off3</data>
			<data>A/C1</data>
			<data>A/C2</data>
			<data>A/C3</data>
		</table>
		<table name="Engine Temp" address="67f8" type="Y Axis" elements="12" scaling="Temp"/>
	</table>

	<table name="Thermo Fan Duty #2" category="Miscellaneous" address="553a" type="3D" level="2" swapxy="true" scaling="Percent (128)">
		<table name="Conditions" address="67f8" type="Static X Axis" elements="3">
			<data>On</data>
			<data>Off</data>
			<data>A/C</data>
		</table>
		<table name="Engine Temp" address="67f8" type="Y Axis" elements="12" scaling="Temp"/>
	</table>