I have an '05 FEH that has been working fine. But now with warmer weather (not hot by any means, high today was only around 70) I am being unable to go EV if I have been (city) driving for any length of time and have warmed up the HV battery. Depending which Scangauge xgauge I use (BTM or Tav), when I get above about 88-89 degrees I can't go EV. And I'm not talking much hotter than that. Today it only reach a ax of like 91.6 and I never got into EV for the half hour after that while on the road before getting home.
FYI, I have a nice clean HV battery duct filter in place.
My questions are:
- Should the HV battery be warming up that much on a 70 degree day in city driving with normal amounts of EV/non-EV cycling?
- At what HV battery temp should I expect it to not go EV? (I'm seeing this happens, as I said, at around 88-89 degrees)
- At what temp will active (A/C) battery cooling take place?
- How long should it take to cool it back down so it will go EV again?

With what I'm seeing, I wonder how anyone in the southern states ever gets any EV use during the summer.

 

"With what I'm seeing, I wonder how anyone in the southern states ever gets any EV use during the summer."

Yes, all the time. Sounds like your HVTB cooling fans have failed or are failing. Lots of info here about this.

 

Should that be throwing a code?

 

If you have a leak in your A/C lines, it would also cause an overheat problem. On a FEH the cooling lines run the length of the car. A sticking battery blend door will also affect cooling.
I've been able to get EV in temps around 100 but not much EV at all around 0.

 

us035976, well the good news is that you have a scanguage. The usual suspects are the blend door and the battery fans. Another possible problem is the AC for cooling the battery is not working right. Using the scanguage, monitor AC. It should kick on when TAV gets to 86F. It should stay on until battery is back around 76F. I had the same problem and replaced the blend door actuator and both fans. Problem persisted. I checked AC on scanguage and found the compressor cycling on-off every second or so when the battery requested cooling, however if I force the AC on by turning the dial into the red AC zone the AC would stay on and cool the battery. I have an indoor/outdoor thermometer (outdoor part) in the cooling channel between the rear AC evaporator and the battery fans. I use it to verify the AC is actually staying on and cooling the air going to the battery. It is also useful for monitoring when/if the blend door is open or closed and when the fans are drawing in outside air.

If anyone has a fix for the AC cycling frequently when the battery requests cooling, please let me know. AC works fine when manually requested, cabin and air after battery AC evaporator is plenty cool (42F, which I assume is means compressor is working correctly).

 

Thanks for the tip. I'll check that next time I have the no-EV problem.