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brim
05-04-2006, 10:49 AM
I've been toying with this one since last year and still can't put my finger on it.

I changed the coolant temp sensor when I replaced the thermostat, was still having problems then even. I replaced the relay for cooling fan 1 today, and I believe I had done cooling fan 2 last year.

Still with the car sitting, the temp gauge will creep its way up to the third tick mark with no fans. Of course turning on the blower will turn them both on, or turning the AC on will trigger it.

Has anyone else had this problem, I can't seem to find a thread on it so I figured I'd ask.

With no fan switch, temp switch, I'm out of ideas.

H.O. Driver
05-04-2006, 11:10 AM
Same problem here, the relays work, they have power but the PCM doesn't command them to go on. When we hooked up the tech II it showed all signs normal even when getting up to the 230* mark, so I am guessing the board in the PCM is starting to die.

I put in the capsers fan switch and they come on fine with that and fine with the AC on, but never on their own. I am going to try a new PCM but I have to up my custom DHP file into it. Not sure when I will be able to get this done.....

Don't worry man, same problem here, you don't notice it in the winter since they never get that hot, but this time of the year it take no time to really crank up there in temp.

brim
05-04-2006, 11:29 AM
it's got me stumped, and as you said, this time of year is where it counts. Although I used to do more traveling till recently, there was nothing like sitting in an hour of traffic with the blower running to keep the temp down

H.O. Driver
05-04-2006, 11:41 AM
Yea, I just picked this up so I can keep the a/c off and that.
Fan Switch (http://www.pfyc.com/store/merchant.mv?Screen=PROD&Store_Code=PFYC&Product_Code=GN3003&Product_Count=8&Category_Code=GAUNDER) Its a temporary solution, but its cheaper and works.

coupe
05-04-2006, 11:46 AM
Same problem here, ive had this problem forever.
So i said F-it and bought the caspers fan switch.

andrewe77
05-04-2006, 12:19 PM
Exact same problem here. I've even had the tank boil over while driving but it was only 3 ticks over 200. Fan turns on when A/C is turned on and cools it down to 200 in no time.

I'm going to replace my thermostat just to make sure it isn't sticking. I think the issue may be that the cooling system in our cars is marginal when brand new but as gunk builds in the radiator, the efficiency goes down. Coupled with the high setpoint of 230 when the PCM engages the fan relays and you have cooling problems.

MikeSilverGT
05-04-2006, 12:26 PM
Maybe it's built in obselence?

Mine still manages to keep the car cool. But I've had the coolant flushed. A good bit of gunk built up on the cap, so I replaced it in case it wasn't holding the seal. I'm just hoping the gunk isn't from oil. Ya know where that one goes...

EDIT: I just thought of something, if your tank is boiling over at a few ticks above 200 then your cap is not holding pressure either. Pressure raises the boiling point for liquids...

coupe
05-04-2006, 12:26 PM
Ive always wondered why these cars run so damn hot.
I have owned 7 cars in my 24 years. This is the ONLY one that gets way to hot for comfort just by idleing.
My truck for instance, i can let that lumber wagon idle in a 100 degree day and the temp wont budge over 180 no matter what. Yet my GA i let it idle on a 60 degree day and within 10 minutes the temp is touching 230 and still rising!!!

Mike Jung
05-04-2006, 07:55 PM
Ive always wondered why these cars run so damn hot.
I have owned 7 cars in my 24 years. This is the ONLY one that gets way to hot for comfort just by idleing.
My truck for instance, i can let that lumber wagon idle in a 100 degree day and the temp wont budge over 180 no matter what. Yet my GA i let it idle on a 60 degree day and within 10 minutes the temp is touching 230 and still rising!!!
How are you guys hitting 110°C/230°F ?

I have never seen my car engine coolant temp gauge hit 110°C/230°F (half way between 90°C/194°F & 130°C/266°F) !


Like today it was 22°C/72°F & 33% humidity outside; & my car was sitting parked in the sun all day.
30-minutes driving home on the highway with rush-hour traffic: my car stayed mostly at 86°C/186°F (1-click below 90°C/194°F).
Until the end of the trip it was at 90°C/194°F & climbed, once off of the highway.
I let it idle in the driveway (testing the coolant system - just got a new water pump put in) up to about 100°C/212°F (3-clicks past 90°C/194°F).
At 100°C/212°F: the fan came on low & reduced the temp to just above 90°C/194°F.

I have never seen it hit 110°C/230°F (half way between 90°C/194°F & 130°C/266°F) :confused:

It sits normally for me, like 1-click below 90°C/194°F; until I get caught up in traffic or after coming off the highway.

H.O. Driver
05-04-2006, 08:08 PM
It gets that high because the PCM isn't telling the fans to come on, they work and have power, they just don't turn on by the PCM's command. So I think its the board in the PCM thats faulty, just making sure it wasn't my lack of IAT sensor (dhp adjustable timing feature), but it makes me feal better to hear that stock cars are doing the same thing. :)

Tony
05-04-2006, 09:02 PM
I noticed my radiator fan seems to cycle on and off intermittently when the weather is hot. It never did this before. Could this mean a new PCM is in order? If so, how much does it cost?

Also, I recently noticed a strong smell like burning electronics coming from inside my car. Of course, it could just be outside air pollution. Anyone else get this? I'm worried it might mean fried PCM.

H.O. Driver
05-04-2006, 10:08 PM
I noticed my radiator fan seems to cycle on and off intermittently when the weather is hot. It never did this before. Could this mean a new PCM is in order? If so, how much does it cost?

Also, I recently noticed a strong smell like burning electronics coming from inside my car. Of course, it could just be outside air pollution. Anyone else get this? I'm worried it might mean fried PCM.
They cycle on and off because your coolant temp will get to a point to where your high speed fans will cycle on, once it cools down enough it will switch to just the low speed fan. For burning electronics smell, check the wires in your engine bay to make sure nothing is getting too hot.

iceman
05-04-2006, 10:39 PM
The PCM commands Low Speed Fans ON under the following conditions:

The engine coolant temperature exceeds approximately 106°C (223°F).
The A/C refrigerant pressure exceeds 1310 kPa (190 psi).
The vehicle is shut off when the engine coolant temperature is greater than 140°C (284°F) and system voltage is more than 12 volts. The fans will stay ON for approximately 3 minutes.


The PCM commands High Speed Fans on under the following conditions:

The engine coolant temperature reaches 110°C (230°F).
The A/C refrigerant pressure exceeds 1655 kPa (240 psi).
When certain DTCs set.

coupe
05-05-2006, 06:21 AM
^^ That sucks becuase mine dosent do that. It didnt even do that when it was 100% stock. Thats why CFS was at the top of my mod list....one of my first mods actually.

H.O. Driver
05-05-2006, 11:59 AM
mine used to come on at the DHP settings, but one day (not sure, it was winter and fans really don't get used then anyways) when it started to get warm again, it got up to 240* and no fans came on at all.

andrewe77
05-05-2006, 02:36 PM
Mine used to never get more than 1 tick over 200 degrees as well but with age, the cooling system doesn't seem to work as well.

Mine eventually starts boiling coolant out even though it hasn't reached the temperature where the PCM turns the fans on. Maybe I have an incorrect coolant mixture or the system isn't being pressurized. I've replaced the cap and I'm quite certain I don't have a LIM or head gasket leak. I suppose the temperature sensor could be faulty but that is highly unlikely.

I think that GM put the temperature setpoint for the fans to kick on too high because over time the cooling system becomes more inefficient due to build up in system.

andrewe77
05-05-2006, 02:39 PM
I have an idea, do any of you have a lot of bent fins on the A/C condenser? Mine seems to have a lot near the bottom due to years of debris hitting it. The condenser sits in front of the radiator so maybe the reduced airflow is bad enough to be causing this problem?

Anyone ever try straightening the fins?

iceman
05-06-2006, 02:48 PM
Coupe and HO driver.. that sucks. I know that a code will be thrown if the fans are on when they shouldn't be, you think the other way around would happen lol .. I've never seen my car above 215.... maybe time for a coolant system flush?

97PGAMGT
05-07-2006, 10:18 PM
I know what you mean, i just had the radiator hoses, and fluid flushed and changed..like 3 days ago, now i gotta check engine light and the Radiotor light is on, is this as well from a faulty thermostat? or PCM??

coupe
05-08-2006, 06:57 AM
Coupe and HO driver.. that sucks. I know that a code will be thrown if the fans are on when they shouldn't be, you think the other way around would happen lol .. I've never seen my car above 215.... maybe time for a coolant system flush?

I have had many coolant flushes, they didnt make any difference.
Im really not worried about it, i would be though if i didnt have CFS.

swordfencer
05-08-2006, 08:56 AM
I thought I was the only one that had this problem. My car will get all the way up to 230+ and the fans will not come on. I took in to the dealer to have them check and they said the computer is working fine. They did say that the temp gauge was reading a little high vs what the scan tool was saying. But still, it seems to happen at random that the fans will not kick on.

BTW, if I am not mistaken, the reason why our cars run hot is to lower emissions.

nascarnate326
05-08-2006, 09:00 AM
Ive always wondered why these cars run so damn hot.
I have owned 7 cars in my 24 years. This is the ONLY one that gets way to hot for comfort just by idleing.
My truck for instance, i can let that lumber wagon idle in a 100 degree day and the temp wont budge over 180 no matter what. Yet my GA i let it idle on a 60 degree day and within 10 minutes the temp is touching 230 and still rising!!!

My GA would do the exact same thing. I trued to keep airflow moving as much as possible, but with 1 and 2 not working 3 was a lil loud. My Cavi will sit all day at 195 (nocks on wood). Hopefully this problem doesnt happen to the G6 people in a few years.

Mike Jung
05-08-2006, 10:18 AM
My GA would do the exact same thing. I trued to keep airflow moving as much as possible, but with 1 and 2 not working 3 was a lil loud...
What are you talking about :confused:

What does (I am guessing) the HVAC blower fan have to do with the engine coolant fans ?

...My Cavi will sit all day at 195...
& your 2.4L Twin Cam 4-cylinder engine also has a 180°F/82°C thermostat.

PS: Does your Z-24 actually have #'s on your engine coolant temp gauge ?
I know that the '98 Sunfire GT doesn't; just a ok range on the gauge.

lone_wolf025
05-08-2006, 10:26 AM
The HVAC system has a mini radiator of sorts buried in the firewall. Its hooked up to the coolant system and when air is blown across it, from having the temp select knob on heat, it will drop the temperature of the coolant.

andrewe77
05-09-2006, 11:56 AM
AKA the heater core

JackNBeth
07-15-2006, 02:29 AM
As to a question on Page 1, "Why do these GAs run so hot?". I asked this very question back in 2000 with my 99 GT1 to a GM plant here in Cleveland, OH. They told me to come in since I was a resident, and my grandfather worked for them for 17 years. I was told that any of the Grand Ams that were originally built with the "Ram Air" package, the engine depends on the air intake from the inlets on the package to keep the engine cool. So, keeping the car running and moving is a must. It's not the best car for heat and traffic. It's better for cruising and racing upgrades. Also, I was told that I should NEVER install a short-ram intake in the car, no matter what. It cuts off more air than doing any good, besides it just lets in engine and exhaust air. The best suggestion that they gave me was to keep the stock "Ram Air" intake, and do mods to the other intake into the Air Box. This is the one that has the Air Dampener on it, located in the front fender wall. I was told to find a better way to extend the pipe to the fender, and make a few mods on the car that involve cutting the fender at the two small indents and opening up the square hole in the air box to a round "diagonal" hole. Then attach a hose from the fender to the air box. Very recommended to find a way to put a filter on the inside of pipe. You can use the screen in front of the MAP Sensor or a cut one out of a house furnace filter. This has not been determined to add performace to the car, because I could not get a straight answer and I haven't been able to get mine done yet. All it was designed to do is add colder air to the engine.

rocketfast123
07-16-2006, 05:38 AM
& your 2.4L Twin Cam 4-cylinder engine also has a 180F/82C thermostat.

PS: Does your Z-24 actually have #'s on your engine coolant temp gauge ?
I know that the '98 Sunfire GT doesn't; just a ok range on the gauge.

My 2.4 will go halfway between 1/2 and 3/4 mark, but that's only on a hot day waiting at a red light. Once it get's that high I guess the t-stat opens to drop the temp, because the fans don't turn on. Now with the a/c on 98 degrees with 100% humidity it will stay at 1/2 mark all day.

timka86
07-16-2006, 03:31 PM
well add me on to this list of people's fans not working. still no one mentions a way of fixing it. whoever replaced the PCM, did it work?

Sprucegagt
07-17-2006, 02:20 AM
As to a question on Page 1, "Why do these GAs run so hot?". I asked this very question back in 2000 with my 99 GT1 to a GM plant here in Cleveland, OH. They told me to come in since I was a resident, and my grandfather worked for them for 17 years. I was told that any of the Grand Ams that were originally built with the "Ram Air" package, the engine depends on the air intake from the inlets on the package to keep the engine cool. So, keeping the car running and moving is a must. It's not the best car for heat and traffic. It's better for cruising and racing upgrades. Also, I was told that I should NEVER install a short-ram intake in the car, no matter what. It cuts off more air than doing any good, besides it just lets in engine and exhaust air. The best suggestion that they gave me was to keep the stock "Ram Air" intake, and do mods to the other intake into the Air Box. This is the one that has the Air Dampener on it, located in the front fender wall. I was told to find a better way to extend the pipe to the fender, and make a few mods on the car that involve cutting the fender at the two small indents and opening up the square hole in the air box to a round "diagonal" hole. Then attach a hose from the fender to the air box. Very recommended to find a way to put a filter on the inside of pipe. You can use the screen in front of the MAP Sensor or a cut one out of a house furnace filter. This has not been determined to add performace to the car, because I could not get a straight answer and I haven't been able to get mine done yet. All it was designed to do is add colder air to the engine.


HAHAHAHAHAHAHAHAHA!!!!!!

This has to be a joke. Anyone who has even bothered to check the routing of the "RAM AIR" ducting would know that it has zero effect on the cooling system. Whoever talked to you at that GM plant clearly had no idea what they were talking about.

As for the fan issue, well unless you know someone that has tuning software or your willing to install a bypass switch, your stuck with the stock settings. My car used to have this problem even with the 180 tstat I installed. But Powrtuner changed all of that. Needle has never touched the 200 mark since then, even with 95 * outside temps.

lvemy3100
07-17-2006, 06:25 AM
tuning software dosent do anything to cure this issue.... we tired (me and timka86)

the fans are somehow malfunctioning.....

brim
07-17-2006, 08:58 AM
for some reason i didn't think there was an easy fix the issue

coupe
07-17-2006, 09:57 AM
Im not overly worried since i have caspers fan switch.

timka86
07-17-2006, 01:55 PM
I don't have a fan switch, so i turn on the A/C and that turns the fans on, and they stay on after you turn the A/C off, but that puts wear on my A/C clutch.

basically it would be nice to not have to watch the temp guage. it looks like all of us that are having this problem are 00 or 99.

so if i get a 2001 + PCM, could it be programmed and work with my 2000 GA?

it could be a 2000 and 99 PCM issue.

coupe
07-17-2006, 02:16 PM
It would be less headache to just buy a capsers fan switch, plus you get a cool toggle switch and a cool little led light.

brim
07-17-2006, 02:52 PM
It would be less headache to just buy a capsers fan switch, plus you get a cool toggle switch and a cool little led light.

lol , however it would be nice if it were not a problem at all

slowbird
07-17-2006, 03:53 PM
My 04 on average sits a tick above 90*c which is the halfway mark.

Like others have said...if I let the card idle for a bit the temp will go between the 1/2 mark and the 2/3 Mark. My fans don't come on...not even with the MMS PCM....though they do stay on after key off for 3 minutes.

I use the A/C in summer so that helps keep the car cool.

I need to get that fan switch.

Sprucegagt
07-17-2006, 04:33 PM
tuning software dosent do anything to cure this issue.... we tired (me and timka86)

the fans are somehow malfunctioning.....

If the relays are functioning properly and power is available to the fans if you jump the relay then it has to be the PCM. I know DHP added class II fan enabling through the PT for Grand Ams. This fixed my problem where the fans would not activate at my revised temp. settings. Does your Malibu have this option?

lvemy3100
07-17-2006, 05:06 PM
If the relays are functioning properly and power is available to the fans if you jump the relay then it has to be the PCM. I know DHP added class II fan enabling through the PT for Grand Ams. This fixed my problem where the fans would not activate at my revised temp. settings. Does your Malibu have this option?


as far as I know most files should have that option....

the issue is with tims ga NOT my malibu....

we lowered his temps before and everything was working just fine ... he just finished his rebuild and came back to get the newest file from me with his fan turn on points since he used a 180 t-stat and now we are having this problem.... we didnt mess with the "class II fan enabling" the first time around or this time and considering the issue is with other un-tuned GA's something tells me the flash had nothing to do with the fan issue... I could be wrong but I cant say for sure till Tim has time to let me take another crack at this issue...

his car was the first I had ever saw or heard of this issue and then I found this thread while trying to find some sorta explanation as to wtf is going on...

the casper's fan switch is a good idea and is an easy fix but I would really like to get to the root of the issue so that people that are having this issue now and in the future can identify and fix it without having to deal with a mechanic

timka86
07-17-2006, 05:50 PM
as far as I know most files should have that option....

the issue is with tims ga NOT my malibu....

we lowered his temps before and everything was working just fine ... he just finished his rebuild and came back to get the newest file from me with his fan turn on points since he used a 180 t-stat and now we are having this problem.... we didnt mess with the "class II fan enabling" the first time around or this time and considering the issue is with other un-tuned GA's something tells me the flash had nothing to do with the fan issue... I could be wrong but I cant say for sure till Tim has time to let me take another crack at this issue...

his car was the first I had ever saw or heard of this issue and then I found this thread while trying to find some sorta explanation as to wtf is going on...

the casper's fan switch is a good idea and is an easy fix but I would really like to get to the root of the issue so that people that are having this issue now and in the future can identify and fix it without having to deal with a mechanic

i believe i had this issue before the rebuild and before any tuning. because last summer, when i bought the car, it would get hot at red lights, and cool off when i was moving, and it also was cooler when i had the A/C on, which puzzled me cuz i figured, with the A/C on it should make it hotter. so this is a PCM issue for sure.

i was at the dealer today, the 99-00 PCM's have a diff part# then the 01-04 PCM's. all the guy could tell me is that there was a difference in the transmission, probably in the line pressure and shift timing, but not for sure.

here's the part #:
99-00: 09380717
01-04: 12209614

could anyone find out the changes made from 00 to 01?

Sprucegagt
07-17-2006, 10:43 PM
I know one hardware change is the O2 sensor. But nothing on the cooling fans. You can run an 01 bin file on a 00 GA. But you have to disable the DTC for O2 heat up time. The O2 sensor in the 01+ models warm up quicker than the 99 and 00 models.

Having the AC "on" automatically turns on fan 1. Thus cooling the car down when the AC is on. How hot did your car get?

timka86
07-17-2006, 11:02 PM
it gets to about 225-230, but the fan turn on temp is set to 185, and i wasn't going by the guage on the cluster, but by realtime scanning with the DHP software.

and if you look at the wiring for the 00' cooling fans, when #1 turns on, it runs in series with #2, so they're on low. It's when the #2 relays turns on, then #1 goes into high speed because then it's running alone, and so is #2.

when you turn on the A/C, first #1 relay turns on, which actually turns both fans on. then about 30-60 seconds later, as the A/C builds up pressure it triggers #2 to come on.

and i know that the coolent sensor is working cuz it's programmed to turn the fans on with key-off if it's hotter then 185, and when it's hotter then that, they turn on, and when it's cooler then that they don't turn on with key off.

NorKoastal
07-17-2006, 11:18 PM
Can a 01+ O2 (Front or Rear??) be installed in a 00?? Im about to swap some sensors/Seafoam.. Im dissapointed in my low end power... In 3rd I still feel I need to law down the petal a bit much to get going... More preventative than fixing..

timka86
07-17-2006, 11:26 PM
Can a 01+ O2 (Front or Rear??) be installed in a 00?? Im about to swap some sensors/Seafoam.. Im dissapointed in my low end power... In 3rd I still feel I need to law down the petal a bit much to get going... More preventative than fixing..

well it's off the topic, but i don't think you can. you'll prolly get a SES or SVS light.

the part #'s for the O2 sensors are different for the 01+ GA's.

Sprucegagt
07-17-2006, 11:56 PM
it gets to about 225-230, but the fan turn on temp is set to 185, and i wasn't going by the guage on the cluster, but by realtime scanning with the DHP software.

and if you look at the wiring for the 00' cooling fans, when #1 turns on, it runs in series with #2, so they're on low. It's when the #2 relays turns on, then #1 goes into high speed because then it's running alone, and so is #2.

when you turn on the A/C, first #1 relay turns on, which actually turns both fans on. then about 30-60 seconds later, as the A/C builds up pressure it triggers #2 to come on.

and i know that the coolent sensor is working cuz it's programmed to turn the fans on with key-off if it's hotter then 185, and when it's hotter then that, they turn on, and when it's cooler then that they don't turn on with key off.

Yeah. I think Iceman posted them earlier but the stock 00 fan 1 turn on temp is 223*F and fan 2 is 232*F. This is according to the data in PT. So hitting 230* before fan 2 turns on is about right.

Change the class II enable setting. It should work then. There is a reason its there. I sent in the ticket on Bugtracker to get this fan issue fixed. :D

timka86
07-18-2006, 06:25 PM
Yeah. I think Iceman posted them earlier but the stock 00 fan 1 turn on temp is 223*F and fan 2 is 232*F. This is according to the data in PT. So hitting 230* before fan 2 turns on is about right.

Change the class II enable setting. It should work then. There is a reason its there. I sent in the ticket on Bugtracker to get it fixed. :D


yeah Mark (lvemy3100) and I are going to try that next. i don't kow what it's for, but if it works, it works. I'll be happy. We'll let you know what happens. thanks

lvemy3100
07-23-2006, 04:54 PM
Thanks for all the info both here and on gmv6pcm.com..

the issue is fixed and Tim seems to be much happier with his car now.

timka86
07-23-2006, 05:07 PM
^^ as stated above, the issue if fixed, it was the class II fan enabling. fans turn on, and everything works great!!

the tune amazing, the car drives awesome. i filled up with 89 octane instead of 87, and i get better gas mileage, and it ripps more, feels like a whole new car.
highly recommend getting a tune from MP RACING!!

Sprucegagt
07-23-2006, 10:07 PM
No problem guys, glad I could help!!

rrh1125
07-14-2011, 05:40 PM
Yeah. I think Iceman posted them earlier but the stock 00 fan 1 turn on temp is 223*F and fan 2 is 232*F. This is according to the data in PT. So hitting 230* before fan 2 turns on is about right.

Change the class II enable setting. It should work then. There is a reason its there. I sent in the ticket on Bugtracker to get this fan issue fixed. :D


Changing the class II enable setting I imagine is something our mechanic has to do. Can you give instructions as to how to do this. Our mechanic did not know that you could change the setting. Also can you suggest what to set it at. Your expertise would be very much appreciated, we have been trying to figure this problem out for quite some time now and finally after searching and searching, spending a few hundred dollars on parts that didn't help, I finally. Found this post on the Grand Am forum.

WidbyJ
07-14-2011, 11:15 PM
You are correct, someone who has a computer link will have to tweak it for you as this is not something you can do with standard tools.
-or-
The alternate I used: I replaced the factory fans with a slim-line dual fan setup that uses a probe-style sensor to feed the temp to an adjustable controller. I just left the factory wiring taped-off out of the way, the new controller came with its own wiring. Adjusted the temp once so the fans come on at 210* and everything is happy (fan speed is variable and they run after power-off if needed). I'm pretty sure it moves more air now, is quieter and allows for a lot more room around the engine. Well worth it for the money and time involved.

rrh1125
07-15-2011, 02:32 PM
Thanks for the info, I would really like to get that setting changed though. My husband and I bought the car, put a new motor in it and it all worked perfectly for quite awhile. I don't want to stick a bunch more money in the car, its a good looking car so it needs to be fixed. Our mechanic does not know how to change the setting so I thought I could gain some wisdom from the experts. Can ya help me out?

AaronGTR
07-15-2011, 03:25 PM
Changing the class II enable setting I imagine is something our mechanic has to do. Can you give instructions as to how to do this. Our mechanic did not know that you could change the setting. Also can you suggest what to set it at. Your expertise would be very much appreciated, we have been trying to figure this problem out for quite some time now and finally after searching and searching, spending a few hundred dollars on parts that didn't help, I finally. Found this post on the Grand Am forum.


Just FYI, this thread is VERY old and Spruce no longer frequents this forum.

I highly doubt your mechanic would know how to change the fan settings and I'd be highly surprised if he even knew it was possible. This is something we do with tuners for custom programming in the engine computer. It's not something they do at a normal maintenance shop. You need a laptop and a tuning interface and program that costs several hundred dollars in order to do it. It is also meant for performance modifications.

IE, this is not something anyone should need to do with a normal stock car. If your fans are not turning on at the factory pre-set temps, then there is something else wrong with the system. First place to check is the fuses and relays, and try jumping wires from the fan plugs directly to the battery to make sure the fans are good.