air intake sensor

It is definately possible to get the ecm to think the temp is 32, same as a feul temp wire but with a different resistor. I have never seen this done, what is the supposed benifit? The ecm may adjust the timing a bit for the colder air but I dont know if you'd see much difference in power, maybe a slight gain in fuel economy in some conditions.

 

I see a big drop in mpg when the air temp is below about 35. I'm not totally sure if this is from the actual air temp or programing in the ecm. If its from the ecm programing I would guess that a air temp wire wouldn't help, but actually hurt ya.

 

yeah same with me,under about 35 degrees and fuel mileage really drops off,some friends that have cats said that there is a update for the atmosperic sensor i am going to research more and see what I can come up with,have to be something with temp,I have been running south last couple days and really noticed difference

 

when the intake air get's up to a certain temp. ECM turns the fan on my truck i can just start up a hill about 15 sec. into a pull like clockwork fan comes on would be nice to have something that done away with that............. as far as timing IDK

 

I never heard of a fan being turned on by the intake air temp. My fan won't turn on till about 210 degrees if I let it. I would have somebody check out the ecm cause something doesn't sound right.

As far as the temp update, I've never heard of it. I have heard of a special program that only a select few have that cures this problem, but I don't think it passes EPA specs. I may be wrong on the update, I hope I am and its available. Let me know if you come up with anything.

 

coolhauler the coolant sensor for the ecm controls fan,may have a glitch in switch,like pilling trucker says they are usually at 210-219 when fans comes on auto,would get hooked up to computer and see what realtime values are.does your fan cycle when you apply your jackebrake?

 

The ECM will turn on the cooling fan, if any of the following conditions are met:

• Engine speed is less than 2250 rpm.
• The engine is not running.
• The engine is cranking.
• The temperature of the coolant temperature sensor for the C-10 and the C-12 engines is greater than 96 °C (205 °F).
• The temperature of the coolant temperature sensor for the 3406E, C-15, C-16 and C-18 engines is greater than 102 °C (216 °F).
• Active diagnostic code for the coolant temperature sensor
• The intake manifold air temperature is greater than 87 °C (189 °F).
• The intake manifold air temperature is greater than 72 °C (162 °F) while the boost pressure is greater than 70 kPa (10 psi).
• The "Fan with Engine Retarder in High Mode" is programmed to "YES" and the retarder has been on at least two seconds.
• The "A/C Switch Fan On-Time" is programmed to a value above 0 and the A/C high pressure switch is Open.
• The ECM is counting after the A/C high pressure switch has closed.
• The "PTO Activates Cooling Fan" parameter is programmed to "Continuous" and the PTO On/Off switch is on.
• The manual fan override switch is on.

 

dealer told me intake air temp. is reason for fan being turned on , he said twin turbo's have so much heat the intake air temps are higher , no glitch with coolant sensor , it does it like clockwork 15-20 sec. into a hard pull fan comes on , i replaced 12 blade fan with 8 blade fan does much better job picked up a gear on a hill, hope to help fan hub live longer -replaced 3 already, would think it would help with MPG too,

 

You may have problems with your waterjacker cooler, It is there to drop air temp before the CAC. If the valve is stuck closed there will be not waterjacket cooling.