Hello everybody, I own a 2008 FEH 2WD with 33K miles, no Nav. system. I live in El Salvador, Central America, the weather it’s about 70 to 90 during this part of the year. I have a ScanGauge II with the BTh, BTl (battery temp high and low) and the programming for DTC detection from the battery pack
Right now I am experiencing the same problem that *‘aleksey2001’ has posted in other forum: car works very fine in the morning –complete hybrid operation after engine warms up- but, once after the battery gets +100F it won’t go EV (on battery) mode but still have electrical assist; I connect the SG II and go around until reach the always get zero codes stored!
Following the *‘Billyk’ check list on that forum:
1- I have revised the operation of the MECS pump and it’s running normal; SG II shows MECS temp form 90 to 105 once the problem is present (colder in the morning). Do you think it’s failing? I don’t think so…
2- I cannot assure the air conditioning for the battery pack is working, with the problem present, the A/C lines are not cold nor condensed – I cannot see any trace of leaks. Cabin A/C is fair; yesterday I put the cabin A/C to 16F but it didn’t solve the problem. Does anybody know at which battery pack’s temperature starts this A/C to cool?
3- I dismantled the blend door actuator –even when no codes stored in my SC II; I disassembled it, cleaned it and reinstalled. When you take this apart, it goes to a middle position, once I put the switch to run, it closed the little door. Do you think it’s failing? I don’t think so…
4- Finally, I can hear the 2 fans running inside the battery pack, one time, I removed the little filter and put my finger inside the little door and I felt a lot of blowing air inside; again, no codes stored.
Well, I’ll try to do something else on the A/C and let you know about, but I have ‘heated’ the battery pack up to 109F and only the ‘parking outside all night’ can cool it. Any advice?

*ref. http://escape-city.com/viewtopic.php...179761#p179761

 

Not sure there is a whole lot you can do other than letting the battery pack AC do its thing. Take it into a dealer and have the system checked out to make sure it is running OK.

 

Everything is normal.
The 2005 to 2008 hybrids do not allow EV when the battery internal temperature is 96°F or above. Usually about 15 minutes of A/C is required to get EV back...

 

I went to one A/C workshop and they found low pressure on the system; then, put extra air pressure looking for some leaks -1 to 1 ½ hr- but didn’t find any. After this test, they put some colored oil and recharged the system…I’ve noticed an instant improvement for the cabin A/C. A few day later, will check the system pressure again or see if something gets dyed.$45 charge.
I went for a trip to heat up my HV battery…I could get EV until 104F…once it reached 105-107 F no EV (of course) but no A/C cooling for the battery itself! When I get home, I’d check the A/C line under the hood and under body and it was dry…of course, the part going inside the cabin was cold and wet…now I am suspecting a failed “battery zone valve” or thermostatic expansion valve…but I have no idea how to test them….

 

I would guess that the valve on the rear A/C box is bad and maybe leaking. After looking through the shop manual, it seems like the zone valve routes refrigerant to the cabin and that it is always routed to the battery A/C. If the A/C is running, the battery should cool off fast - I've seen it drop 20 degrees F in less than half an hour of freeway driving. Anytime the battery temp is more than 85 F, the A/C will run even if the cabin A/C is not on. The battery temp is using the TAV xgauge since the other one doesn't work on my 2008. I lose EV at 95 F, but I don't know at what temp I lose assist because I don't think that has ever happened to me and suposedly it is very hard not to notice when it does.