I have a slightly OT suggestion/question.

I understand the warming up of the ICE thing in a fresh start up but why can't we have EV mode first without ICE running first? I live in a quite neighborhood that has short blocks and speeds are about 20MPH from stop to stop. I would like to be able, if there is enough charge available, to run in EV mode first and then when needed or once out of the side streets and onto the main streets have the ICE do it's charge and warm up thing. If this were to happen it would add more MPG's and better utilize the EV mode in an area that is best suited for it.

I too would like the EV button to force EV mode as long as possible.

I've poked around and a Ford EV button is on the books for me to install.

My car is 3,000 miles till end of warranty, then I'm going to put one in.
If it works ( and the only way it wouldn't is if the car has enough logic to know I'm "cheating" which I don't think it does... ) then I will put out a low cost DIY kit onto Ebay or this site ( or both ). I'm talking something professional and durable enough to last the life of the car. Cost for the kit should be well under $50.

But that's all I'm going to say till I have proof my concept works.
-John

You can get a cheap resistor, some wire and a switch to get an "EV" button. It is easy to spoof the CHT sensor to 190F, at which point the warm-up conditions will be met if SoC>42%. This would cost a few dollars at the most unless you have to have an exceptionally elegant looking button. It will still require that the ICE run for about 30 seconds or so at initial start-up, but it could really reduce the FE hit in cold weather. After the CHT reaches 190F, EV is allowed at much lower temps. I have been really irked when my CHT seemed to be parked at 188F (it goes in steps of 2), causing the ICE to stay on in stop-and go traffic and costing me lots of MPG's.

It's not quite that simple in reality.
There are at least 3 modes, based on 3 types of weather, and 3 sets of rules the car follows. I'm also looking to making something automated, and foolproof, one that will not spoof the car when it is exceptionally cold, or exceptionally hot....but one that will help users like yourself get through all those "borderline" cases that are so frustrating. Plus, there is a high range and low range resistor... but at this point I don't think that matters...

Carl, I'm 99% sure my CHT moves in 1 degree increments... I know I've seen 200, 201, 202, 203... I just can't confirm if I've seen these in a row, or if it was 200, 202 yesterday, and 201, 203 today...

John, you can count me in as interested. I wouldn't want to be to invasive since my FEH is still under warranty, but I would be interested in infrequent 'override' periods whereby I could force a little longer EV mode. Nothing harmful, but I also hate it when the ICE comes on just as you come to a stop sign/light. If I could keep it off until the light turns Green I would be happy.

I'll be watching this one closely. Keep up posted please. I also like Allen's suggesion above about being able to start in EV mode, then when SoC drops below the threshold, start the engine and begin the overall cycle. This just seems like a no brainer, unless I'm missing something. Satisfies the environmental requirements just the same.

If all else fails, I'll look into the CHT temp override suggested by Carl. I'm sure that sensor uses a thermistor, so whatever the ECU expects in the way of resistance to equate to CHT >

The CHT will read in 2 degree increments if it is coded correctly. That is the scaling for that PID for all Fords that I have found.

The hot side/cold side for the CHT is irrelevant since the sensor resistance doesn't change. The resistor that is switched is the one from Vref to the sensor, and is just used to get sufficiently large delta readings over a wide temperature range.

I have never driven the FEH in really cold weather, so I guess I haven't seen any of the other operating modes you mention. I don't know if just the CHT spoofing would work then, but it's all I think I'll need.

Carl... another case of we are both correct.

The CHT is degrees C really, but thanks to scaling... it is in the more familiar degrees F. Therefore, the CHT readings move in 1 degree C and move in 1.8 degree increments F.

Since there is no decimal point,
what we see is 2-2-1-2-2-2-2-1-2-2-2-2-1 and so on.
I knew it wasn't always 2 degree moves.


There is for sure no water temperature probe.
The CHT and fWT probe are one and the same, just different scale.
They both move in a linear fashion, relative to each other.

The CAT temp also moves in a linear fashion based on time.
If the CAT is 1000 degrees, it always cools 100 degrees in 50 seconds when the ICE is off for example.

Meaurements tonite in a 40'F garage:
CHT set to constant 240'F
( and fWT set to constant 191'F )

ICE off at CAT 1049 ICE on at CAT 963
ICE off at CAT 1063 ICE on at CAT 933
ICE off at CAT 1053 ICE on at CAT 946
ICE off at CAT 1061 ICE on at CAT 934
ICE off at CAT 1052 ICE on at CAT 942

I didn't have a stopwatch, but that's a roughly 100 degree increment each time, and a roughly 50 second increment each time. Very predictable.

This is not a hard rule. This was the rule in a controlled environment, car in park, in a 40'F garage ( door open of course ). I have had EV at CAT 750 under different conditions.

So in addition to spoofing the CHT, anyone know how to spoof time???
Since it seems the CAT cools based on time of engine off not on CHT temperature. It always cools 2 degrees per second.

BTW, the electric radiator fans come on at CHT 260 / fWT 206.

-John

Have a look at the attached graph of actual temperature readings.

Attached Files

CHT readings.pdf (9.8 KB, 10 views)

[quote=KenE;157937]John, you can count me in as interested. quote]


Me too.

2005 AWD Escape Hybrid
Best Interstate tank trip MPG 39.02 (scangauge II) for 402 miles on I-70, 10.3 gallons used over mostly flat terrain. Aug. 2007

Best Interstate tank trip E30 MPG 34.6 for 271 miles along I-80 in Indiana and Ohio. May 2008

Best multiple road tank trip E30 MPG 36.2 for 202 miles in Southwestern Pa. July 2008.

The CHT can NOT read odd numbers unless it is coded wrong! The PID returns an integer for degrees F that is multiplied by 2 to get the reading.
It will always move in 2 degree F steps.

The only explanation for an odd-number reading is that either the coding for the add-a-gauge is wrong or the scangauge is screwing up somehow.
Mine works correctly, every time.

Or yours is working incorrectly....

Would you like me to take a picture ( or video ) of mine moving in 1.8 degree steps?

Which makes more sense? The temperature being Degrees C native, or Degrees F?

99% of the world uses degrees C and 1 degree C = 1.8 degrees F.

Mine reads odds and evens, but always in the pattern described below.
Maybe your SG has the "other" processor.

That's the only way I can describe what you are seeing.
-John

P.S. Carl... 0.9 x 2 = 1.8. The SG will report 2 on the display. Likewise 3.6 x 2 = 7.2, and the SG reports 7.
The SG quite certainly reports odd numbers.