JSCAN engine fan function vs. tazer "cooldown" feature

[ShadowsPapa]

Snowplow season again. To recap, running a Wester snow plow on the front of my JT causes a low pressure ahead of the grill and pulls warm engine bay air forward, and across the ambient temperature sensor mounted in the upper left side of the grill area on these. It also causes the air to not flow through the radiator, elevating engine temps a bit.
The result -when it's 0 to 10 degrees out, driving down the road anything over about 35 mph and you see the ambient temp climb up into the 90s (I've hit 101 before) killing the HVAC making it really cold in the cabin, and, the engine temp climbs up to about 220-225 when it would normally run about 190 in weather like this. I know the cause, it's been proven and I've posted about it here several times, so that's not a discussion.

Snow this last week, I mounted the plow and used it, then there's maybe more coming Monday (I HOPE) so I left the plow on but we needed to use one of our Jeeps to get to church tonight - 26 miles, about a 30-35 minute drive. We've racked up some miles on her JLU and she's trying to not drive it as much, so........ I decided to try something.
JSCAN has a live feature that allows you to turn on the engine fan - on high. But - it kicks off about every 5 minutes or so. Not sure if that's a JT thing or a JSCAN thing - it says "sorry, function not working, try again" or something like that and the button goes back to green and the engine fan shuts down.
The good thing is -even at highway speeds, when the outside temp was 28 degrees and I saw the ambient temp climbing up to 72 degrees and watched the engine temp go up to 220, I hit the button on my phone/JSCAN, triggered the engine fan and the ambient temp dropped back down and the engine temp dropped like a rock back to 190.
So, it's a way I can actually drive and use my JT with the plow on it and not freeze my butt off!

I know tazer - both lite and mini can also do this, through a steering wheel button combo - my question is, if you have the engine running, driving, and engage the engine fan with tazer, does it keep running until you shut it off, or does it time-out like it does with JSCAN?

I don't mind having to hit my phone screen every few minutes to turn the fan back on, I don't drive it much with the plow on anyway, but when I do need to leave the plow on and drive it on the road, I really need that function as it absolutely solves the problem of the low pressure area between the plow and grill.

To rephrase, the executive summary:

JSCAN, Go to trail view, bottom of the screen it will say "tap for more" and you'll see more icons across the bottom of the screen. One is the engine cooling fan - you can turn it on with that icon.
but - it times out after 5 minutes or so.
Does it do that with tazer (cool down feature)

Sponsored

 

[Lost1wing]

First off, it is great to hear from you.

I have not tried Jscan or Tazer to control my fan on the JT. I have no need. What I can say is, I use a Diablo tuner to control the engine coolant temperature on my Grand Cherokee. The oem programming would let the Coolant temps get up to 240f range when climbing a hill, going slow. Diablo changes the specified temperature and the computer commands the fan on to meet the new parameter that I entered.

I'm wondering if commanding the cooling fan on with Jscan or Tazer is just confusing the computer because the fan is coming on out of the specified temperature range. Is there a way to change the target temperature with Jscan or Tazer and not just turn the fan on?

I see now that they have a Diablo tuner for the JT. Ouch! I would definitely look at an option to set the desired coolant temp with Jscan or Tazer. Maybe a future update will have an option to set a specific temperature range.

 

[Gvsukids]

I know tazer - both lite and mini can also do this, through a steering wheel button combo - my question is, if you have the engine running, driving, and engage the engine fan with tazer, does it keep running until you shut it off, or does it time-out like it does with JSCAN?

https://www.jeepgladiatorforum.com/forum/threads/diesel-cooling-options-and-ideas.46298/post-759264

https://www.jlwranglerforums.com/forum/threads/tazer-live-functions-cool-down-mode.121200/

 

[ShadowsPapa]

I'm wondering if commanding the cooling fan on with Jscan or Tazer is just confusing the computer because the fan is coming on out of the specified temperature range. Is there a way to change the target temperature with Jscan or Tazer and not just turn the fan on?

Tazer tells the system that the transmission is at 229 degrees.
I might be able to assume that since it's doing that, the fan would remain on until you disabled it via tazer, but that's an assumption based on how it gets the fan to come on to begin with.
I didn't notice any changes in the transmission temperature while using JSCAN, but then I was using only the phone to monitor things on the JSCAN "trail view" screen - and it kept giving ND (no data) for some things as if the connection couldn't keep up and I didn't really think to check the transmission temp on the cluster on the "information" pages right in front of me.
So, at this point, unsure as to how JSCAN accomplishes the task, but the tazer folks make it very clear - "we lie and tell the system the transmission is running 229 to get the fan to come on" (well, not a quote, but may as well be!)
I don't own a tazer myself - I've just not felt the need at all, however, if tazer can lock the fan on and I don't have to keep turning it on like in JSCAN, I could be tempted to get a tazer LITE since it does this for a lot less money than full tazer mini.

https://www.jeepgladiatorforum.com/forum/threads/diesel-cooling-options-and-ideas.46298/post-759264

https://www.jlwranglerforums.com/forum/threads/tazer-live-functions-cool-down-mode.121200/

As far as the Wrangler thread -
Tazer cooldown mode won't work with engine running IF you have a manual transmission. It could also be an issue that he has an eTorque. So we're not really comparing apples to apples. eTorque really throws that into a different area.
That may be why the guy in the wrangler forum couldn't get it to work for him -eTorque?

On the diesel cooling thread - yeah, I know it will function with engine running, IF it's an automatic, but my question would be - will it stay engaged until the driver uses the steering wheel buttons to turn it off, or does it time out like JSCAN does?

• Cooldown Mode: Press the right arrow and
cruise cancel button at the same time to
turn the engine fans on High. If the engine
is off, the fans will turn off automatically
if the battery voltage drops below 11V.
Transmission temperature will read as 229F while this mode is being used with the engine running. (only works with the engine off on manual Jeeps)

That's from their manual/book/pdf.

I'm going to "guess" that it keeps the fan running until told otherwise, but would prefer an actual tazer user who has an automatic transmission (not a manual, not eTorque, not 4xe) confirms it.

JSCAN also runs the fan on command, but, after about 5 minutes, it drops the fan.
Does tazer do that, or keep it running until told otherwise?

 

[ShadowsPapa]

Got a response from the OBD JSCAN guy - they use a very different method to trigger the fan, so it's only temporary and does time-out.

Here's his response:
it's the vehicle that cuts it off, because what JScan does is sending a signal to trigger a fan service procedure

Tazer tells "the systems" that the transmission temp is 229, which causes the fan to come on. ASSUMING that tazer keeps that lie alive, I'd assume that the fan would remain on while driving down the road as normal, but still would prefer actual solid confirmation.

I've found that triggering the cooling fan does indeed help to mitigate the snow plow's low pressure area between blade and grill.
Now I have done a "proof of concept" experiment, I know that I can at least drive it without having to drop the plow off each time I need to drive the JT somewhere.

I know others had a similar question because their snow plow was causing the ambient temp sensor to read too high, causing HVAC issues in the cabin.
So someone with a JT and snow plow, there's hope..................

 

[ATL_Rubi]

Got a response from the OBD JSCAN guy - they use a very different method to trigger the fan, so it's only temporary and does time-out.

Here's his response:
it's the vehicle that cuts it off, because what JScan does is sending a signal to trigger a fan service procedure

Tazer tells "the systems" that the transmission temp is 229, which causes the fan to come on. ASSUMING that tazer keeps that lie alive, I'd assume that the fan would remain on while driving down the road as normal, but still would prefer actual solid confirmation.

I've found that triggering the cooling fan does indeed help to mitigate the snow plow's low pressure area between blade and grill.
Now I have done a "proof of concept" experiment, I know that I can at least drive it without having to drop the plow off each time I need to drive the JT somewhere.

I know others had a similar question because their snow plow was causing the ambient temp sensor to read too high, causing HVAC issues in the cabin.
So someone with a JT and snow plow, there's hope..................

About to hop in the jeep for a ride and will confirm, but if I remember correctly, tazer will “cycle” the fan speed, meaning at times it’s 100% and then cycles to 80% back up to 100. Other than that, I’ve run it on the highway in Georgia summer at 95+ degrees and it just seems to keep running without a lapse in fan speed.

** edit to add: I’ve run it while the jeep is in park with a dog inside (just didn’t want the system to work too hard to stay cool) and gone inside the store for 5+ minutes and the fan is still running. I think as you mentioned, so long as the system believes the transmission temp is 228+, the fan remains on

 

[ShadowsPapa]

About to hop in the jeep for a ride and will confirm, but if I remember correctly, tazer will “cycle” the fan speed, meaning at times it’s 100% and then cycles to 80% back up to 100. Other than that, I’ve run it on the highway in Georgia summer at 95+ degrees and it just seems to keep running without a lapse in fan speed.

** edit to add: I’ve run it while the jeep is in park with a dog inside (just didn’t want the system to work too hard to stay cool) and gone inside the store for 5+ minutes and the fan is still running. I think as you mentioned, so long as the system believes the transmission temp is 228+, the fan remains on

Thanks, yes, that is how I'm thinking. As long as it's being told things are warming up, it would, or should, run the fan.

If all of that is correct, people would have two choices to keep the HVAC seeing a more accurate outside/ambient temperature and keep operating the heat, as well as keeping the engine temp in a more typical range for winter:
JSCAN - and touch that fan icon every 5 minutes or so to keep the fan running (on high, you can hear the thing inside the cab)
Much cheaper option, not as convenient. I use JSCAN for a lot of other things.
or
Tazer (Lite will do this) - it fakes the systems out, causing the fan to run. Likely, all but proven, it would keep the fan on until you hit the buttons, or shut the truck down.
Pretty expensive solution, unless you want it for other functionality, which isn't unlikely.

Proof of concept absolutely worked, so there's a solution for keeping the heat going in the JT when running a plow on the front. **

** It's not a problem while plowing as the vehicle speed is so slow there's no low pressure area formed between the blade and the grill. In fact, you may get hot inside the truck while working the shifter between R and D, and manipulating or controlling the plow blade with the hand-held controller.
The issue only exists while on on the road, over about 30-35 mph.

I'd be tempted to use a Tazer for this if I could find a good used Tazer Lite really cheap.
But for now, JSCAN works as I don't often need to drive my JT anywhere when the plow is mounted, it's not common.

 

[ShadowsPapa]

Thanks to admin for moving this thread- makes far better sense here!
Key words for searching:
blade, snow, plow, snowplow, HVAC, heat, fan, temperature, sensor

 

[Mr._Bill]

Maybe you could run a flexible tube attached to one of the lights on the snow plow down to the temperature sensor. Create a separate duct to bring the cold air to the sensor.

You could try adding a separate 12v fan to move air across the sensor. If needed, add a tube to duct air, something like a bathroom exhaust fan on a smaller scale.

 

[ShadowsPapa]

Maybe you could run a flexible tube attached to one of the lights on the snow plow down to the temperature sensor. Create a separate duct to bring the cold air to the sensor.

You could try adding a separate 12v fan to move air across the sensor. If needed, add a tube to duct air, something like a bathroom exhaust fan on a smaller scale.

That's getting a bit complex - and adds to the mounting and dismounting of the plow. You'd have to account for all blade positions. You would have to have a way to attach it to the grill at the sensor, semi-permanent, but easily removed while taking the blade off the truck. You'd be doing all of that in pretty cold temps, likely in wind.

it also wouldn't address the engine temperatures as little to no air is flowing across the radiator due to that low pressure area - a bit lower than the air pressure in the engine bay.

The solution is already in the truck - the cooling fan. The thing is which option best to trigger it (price vs. convenience and so on)

 

[IamPro2A]

I've never had the need to test that Tazer function either, but I do know that the guy from Z Automotive is usually pretty responsive to questions as well. He might be able to give you the definitive answer you need. Which reminds me, I still need to find out if the Tazer JL will work on the 2025 JLU that I have on order for the wife. I assume it should, but I know better to assume anything.

PS: glad to see you posting, people were worried.

 

[Mr._Bill]

That's getting a bit complex - and adds to the mounting and dismounting of the plow. You'd have to account for all blade positions. You would have to have a way to attach it to the grill at the sensor, semi-permanent, but easily removed while taking the blade off the truck. You'd be doing all of that in pretty cold temps, likely in wind.

it also wouldn't address the engine temperatures as little to no air is flowing across the radiator due to that low pressure area - a bit lower than the air pressure in the engine bay.

The solution is already in the truck - the cooling fan. The thing is which option best to trigger it (price vs. convenience and so on)

Make it simpler. Just add a separate cooling fan in front of the radiator that you control with an Aux switch.

There is also a module available to control the cooling fan. I've seen it referenced in a lot of the overheating threads.

 

[ShadowsPapa]

Make it simpler. Just add a separate cooling fan in front of the radiator that you control with an Aux switch.

There is also a module available to control the cooling fan. I've seen it referenced in a lot of the overheating threads.

I see a couple of problems - more structure to impede airflow when the normal fan isn't running, and, more complexity compared to simply turning on the normal cooling fan with software or tazer.
Let's see - cost of a fan, making brackets to mount it, running the wiring harnesses and so on......... and of course, if trading the truck in, in the future, taking it all back out again.
So we have the costs of materials and installation. I'd also wonder about the airflow since a fan would be impeding flow during normal summer operation unless you also ran that added fan.

I don't have overheating issues, except when the plow is on for a couple of days, so simple is best. It would only ever be used maybe 3 or 4 times a season, tops. Hard to justify too much into it.

Just trying to get through pros and cons, and COSTS.

If I wasn't going to use JSCAN or tazer, I'd wire in a relay that was controlled by an aux switch that would supply full power to the cooling fan to operate it. The issue would be - I believe the PCM actually knows when there's a problem with the fan circuit and would likely freak out if it didn't detect an operable fan there, and to supply current to the fan circuit outside of the control of the PCM might also cause an issue.

It sees the least intrusive, most simple method would be tazer lite - but that's still over $200, so far, JSCAN has worked fine, just inconvenient to have to hit that icon every few minutes to run the fan again.

any added fan would have to fit here, not obstruct air flow at all (meaning fan and brackets would have to allow this much air through -

 

[Mr._Bill]

I see a couple of problems - more structure to impede airflow when the normal fan isn't running, and, more complexity compared to simply turning on the normal cooling fan with software or tazer.
Let's see - cost of a fan, making brackets to mount it, running the wiring harnesses and so on......... and of course, if trading the truck in, in the future, taking it all back out again.
So we have the costs of materials and installation. I'd also wonder about the airflow since a fan would be impeding flow during normal summer operation unless you also ran that added fan.

I don't have overheating issues, except when the plow is on for a couple of days, so simple is best. It would only ever be used maybe 3 or 4 times a season, tops. Hard to justify too much into it.

Just trying to get through pros and cons, and COSTS.

If I wasn't going to use JSCAN or tazer, I'd wire in a relay that was controlled by an aux switch that would supply full power to the cooling fan to operate it. The issue would be - I believe the PCM actually knows when there's a problem with the fan circuit and would likely freak out if it didn't detect an operable fan there, and to supply current to the fan circuit outside of the control of the PCM might also cause an issue.

It sees the least intrusive, most simple method would be tazer lite - but that's still over $200, so far, JSCAN has worked fine, just inconvenient to have to hit that icon every few minutes to run the fan again.

any added fan would have to fit here, not obstruct air flow at all (meaning fan and brackets would have to allow this much air through -

I would hunt down that fan controller and see if you could make that work. I looked at it once, and they sell several versions of it.

 

[Mr._Bill]

I see a couple of problems - more structure to impede airflow when the normal fan isn't running, and, more complexity compared to simply turning on the normal cooling fan with software or tazer.
Let's see - cost of a fan, making brackets to mount it, running the wiring harnesses and so on......... and of course, if trading the truck in, in the future, taking it all back out again.
So we have the costs of materials and installation. I'd also wonder about the airflow since a fan would be impeding flow during normal summer operation unless you also ran that added fan.

I don't have overheating issues, except when the plow is on for a couple of days, so simple is best. It would only ever be used maybe 3 or 4 times a season, tops. Hard to justify too much into it.

Just trying to get through pros and cons, and COSTS.

If I wasn't going to use JSCAN or tazer, I'd wire in a relay that was controlled by an aux switch that would supply full power to the cooling fan to operate it. The issue would be - I believe the PCM actually knows when there's a problem with the fan circuit and would likely freak out if it didn't detect an operable fan there, and to supply current to the fan circuit outside of the control of the PCM might also cause an issue.

It sees the least intrusive, most simple method would be tazer lite - but that's still over $200, so far, JSCAN has worked fine, just inconvenient to have to hit that icon every few minutes to run the fan again.

any added fan would have to fit here, not obstruct air flow at all (meaning fan and brackets would have to allow this much air through -

Depending on where the sensor is, even a small fan mounted using the two open holes at the top may be enough. That should not interfere enough to be a problem for regular use during the rest of the year.

Sponsored