FEH and extreme cold climates-any issues?
Ridiculously Active Enthusiast
Joined: Apr 2008
Posts: 895
From: Los Angeles
Re: FEH and extreme cold climates-any issues?
... BTW: I don’t see an OAT thermistor in the wiring diagram. I suspect, if the system
measures OAT at all, this is done by reading the Cylinder Head temperature immediately on startup.
Also: OAT is irrelevant to the battery charging issue. Only battery temperature itself is
relevant and that is measured by the FEH system.
measures OAT at all, this is done by reading the Cylinder Head temperature immediately on startup.
Also: OAT is irrelevant to the battery charging issue. Only battery temperature itself is
relevant and that is measured by the FEH system.
Ridiculously Active Enthusiast
Joined: Apr 2008
Posts: 895
From: Los Angeles
Re: FEH and extreme cold climates-any issues?
FEH battery has 4-5 bars and not have to six bars. The IMA battery control module(s) allows the battery to overcharge.
Occasional overcharging is a desirable function, but too many frequently repeated cycles of overcharge can damage the IMA battery.
This damage is the result of excessive current and heat build up.
Unique local topographical and ambient conditions in affected states, combined with a driving cycle that typically keeps the IMA battery fully charged, creat this potential problem.
Occasional overcharging is a desirable function, but too many frequently repeated cycles of overcharge can damage the IMA battery.
This damage is the result of excessive current and heat build up.
Unique local topographical and ambient conditions in affected states, combined with a driving cycle that typically keeps the IMA battery fully charged, creat this potential problem.
Ridiculously Active Enthusiast
Joined: Nov 2006
Posts: 1,747
From: Southwestern Pa
Re: FEH and extreme cold climates-any issues?
Could it be possible that this OAT sensor is "wired" directly into the display and not thru the ECU? The Gentek mirrors are wired this way.
Ridiculously Active Enthusiast
Joined: Jan 2009
Posts: 863
Re: FEH and extreme cold climates-any issues?
The original issue was whether the block heater was a good idea.
Here’s some info from the Owner’s Manual, p.196, Driving:
“Use of an engine block/high voltage battery heater is strongly recommended if you live
in a region where temperatures reach -10 ºF or below. For best results, plug the heater in
at least three hours before starting the vehicle. The heater can be plugged in the night
before starting the vehicle.”
Here’s some info from the Owner’s Manual, p.196, Driving:
“Use of an engine block/high voltage battery heater is strongly recommended if you live
in a region where temperatures reach -10 ºF or below. For best results, plug the heater in
at least three hours before starting the vehicle. The heater can be plugged in the night
before starting the vehicle.”
Imported from Detroit
Joined: Apr 2009
Posts: 1,051
From: Michigan
Re: FEH and extreme cold climates-any issues?
The PCM shows no input from the AAT sensor but that surely might be different on a FEH.
Ridiculously Active Enthusiast
Joined: Apr 2008
Posts: 895
From: Los Angeles
Re: FEH and extreme cold climates-any issues?
I had a Gentec on my last vehicle. I liked it. It was wired directly to a sensor that I put in front of the radiator. But it is direct wired because an aftermarket install will always NOT want to interfere with the current vehicle programming.
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Joined: Sep 2006
Posts: 1,678
From: Beautiful Pacific NW
Re: FEH and extreme cold climates-any issues?
Is there ANY modern day vehicle that DOES NOT have a "LAN" (Local Area Network) for interconnecting all the various ECU functions...??
Imported from Detroit
Joined: Apr 2009
Posts: 1,051
From: Michigan
Re: FEH and extreme cold climates-any issues?
There are many inputs/outputs on the '09 FE PCM but there isn't one labeled as Ambient Air Temperature Sensor. If you want to disagree with that point and/or Ford's manuals you'll have to speak to them!
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Joined: Apr 2008
Posts: 895
From: Los Angeles
Re: FEH and extreme cold climates-any issues?
I'm not sure why the FE would need to know the external temperature.
Joined: May 2005
Posts: 2,468
From: Jupiter, FL
Re: FEH and extreme cold climates-any issues?
The PCM monitors many sensors for inferred and direct temperatures and pressures. These sensors are for controlling fan speeds, Air/Fuel ratios, A/C Evaporator Temperature (ACET) which is connected to the Dual Automatic Temperature Control (DATC) (evaporator temperature is transmitted to the PCM from DATC through CAN), A/C Low Pressure Switch (to turn Off and prevent the evaporator from freezing), Head (CHT), and others such as the Intake Air Temperature (IAT) which is integrated into the Mass Air Flow (MAF) sensor. The IAT sensor is used for information for the PCM to adjust fuel and ignition timing.
Hope this helps everyone!
GaryG
