Is power limited when ambient temperature is under 38F?

Regarding the 3.5L V6.

Does anyone know if the ECU limits power when the outside temperature is under 38F?

If it is limited does anyone know if the ECU uses the same temperature sensor that is in the front of the truck by the hood latch?

Background: I noticed the other day that my truck seemed to have less power than normal. The outside temperature was in the high 20s F. The truck was at full operational temperature. I believe Matt (OVTune) once mentioned that low outside temperatures will cause the engine to limit power.

EDIT: I should mention this is for a supercharged Tacoma with several other performance mods. Generally I can smoke the tires from a stop though in low temperatures I can barely get them to chirp.

 

I have not noticed this on my truck.

 

Hmmm, my bet would be considerably more power below 38°F; my Tacoma certainly seems more powerful when it is cold outside.

 

I haven't had this problem even in single digits.

 

We are currently at -20 f and my truck power seems normal. You can notice a bit more sluggish operation which I'm guessing is due to the oils in the diff and trans being stupid cold

 

I noticed it too, but I just figured it was just a combination of added drag from cold air, cold fluids, and winter gas being less powerful.

 

Nothing I have noticed in a few NH winters

 

No. Why. No advantage for anything.

 

Once all of the fluids warm up, then the engine will definitely have more power as the weight of the intake charge will be measurably heavier the colder the OAT gets. The heavier the intake charge, the more power the engine can put out.

 

My truck feels peppier in cold weather.

 

The modern truck comes with sensors and stuff (e.g., MAF, Throttle body) that compensates for temperature air density etc. The truck could want attention.

 

Was the truck cold? I could see the ECU limiting output before everything is to proper operating temp but if everything was already warmed up I can't see denser air as being a bad thing. It rarely gets that cold in Phoenix but I've never noticed a decrease in power once the vehicle is at operating temp.

 

Haven't seen that here in Minnesota. Wind chill is -35 this morning and truck runs just fine

 

Wind chill is irrelevant when it comes to engine output; then only temperature which matters is the OAT.

 

So does mine now that I think of it!

 

Yessir. It was noticed when testing S/C tunes. It is a bit surprising that it is noticeable on an N/A Taco. I'm not sure what the torque limit is. Been a while.



Just saw your edit. There is a cold coolant temp torque limit on the Magnuson tune. It is also a limit on a fully warmed motor under that temp. We never got around to testing a jumper or resistor in the ambient temp sensor. I know folks who did that trick on the motorcycle side for diagnostic purposes.

It is also present in the vF Tuner EROM. Graphic incoming.

 

It has been -30c (-22f) for the last week and no power loss here, not anything noticable anyways!

 

With temperatures that cold, you should have considerably more power.

 

Thank you for your input.

I noticed the engine temperature limit on the Magnuson tune ( Obvious limit on engine power prior to the engine warming up). Though I have since went to the 87mm Yota Werx tune (which is WAY better than the Magnuson tune). The primary reason I am asking is I am scheduled to dyno my truck next month and I fear if there is a power limiter on low outside temperatures the dyno session will be a waste of time. Though if I can say conclusively there is a power limiter and the ECU reads the outside temperature from the sensor by the hood latch then I can easily trick that sensor.

I am probably just going to have to test that theory on the next cold dry day.

 

The only way to do something like that would be if the software could prevent the throttle from fully opening. Assuming that isn't possible, then the ECU will provide the appropriate amount of fuel (in weight) to the amount of air (in weight) in the intake charge. Said another way, the more air which enters the intake at any given throttle setting, the more power the engine produces. Simple physics.