The normal operating range of the battery is 25C (77F) to 38C (100F) with an ideal temperature of 28C (82F). You will get a DTC (warning light) if the battery temperature gets to 57C (135F). Also, a failure of any of the internal battery climate control components/circuitry causes a DTC to be flagged. If the fans are not working you should have a warning light. If the harness wiring is bad I don't know if a DTC code will come up.

The battery should have fail safe protection which is it will stop charging or discharging when it is to hot or to cold. This may be why you can't go EV over a 38C temperature. The battery control module controls the temperature so yes, there is sort of a thermostat sensor. When my battery gets to hot from charging, I can't go EV unless I tap the brake pedal while moving in neutral. Try this after the battery gets hot and let us know the results.

I am a disabled Fire Chief now but I use to build race engines in my younger days. I read as much information I can on the Ford Hybrids and have learned some things on these forums. I may change my battery blend door actuator myself in the near future but I do limited work on the '05 FEH.

GaryG

 

good work man ,
ive tried to tap the brakes many times on nutral and nothing happens i dont know why , the temperature of the battery never exceeds 44c and the is no warnings,

but if the cooling system is good then why it want going below 44 ?? and if the fans is bad i think there should be warning and the battery should exceed 44c ?? right ??

so , where is the problem ?? i think it should be a thermostat or sensor contolling this ?? but what is it ??and where is it ??

 

You have not got a temperature reading of PID of 57C or more so a DTC may not have been flagged yet. It is true if the fans or circuits are bad you should get DTCs P0A96 or P0A81. The other possibility is the Traction Battery Control Module (TBCM) may have a bad connection. There are a 6-pin and 40-pin connectors to the TBCM that you can check for corrosion or pushed-out pins. The manual says you don't have to disconnect the high voltage connectors when following this procedure. Disconnect these connectors and check this and clean or repair if problems are found.

GaryG

 

mmm
im a little stupid in mechanical engineer, but ?? where is the TBCM connection location !!

is it a stupid question ??

by the way, while i was looking under the front passenger seat i found the CD changer !!

wow i was proud of my intelligence , hahah !!!

 

Sorry, the 6-pin and 40 pin connectors are low voltage and can be accessed just behind the rear 60/40 split seats. Pull the carpet up behind the drivers side "60" rear seat after folding it down. You will see the two plugs (6-pin and 40-pin) connected to the TBCM which is inside the battery housing. Very easy to see the connectors and unplug them for inspection for corrosion or pushed-out pins.

Also, that under seat CD player is for music and the one on the Nav System is for Nav CD's or music.

GaryG

 

cool man ill check them now and ill tell u what ill found !!!,


thanks for ur kind

 

hello once again man, im really desperate, ive found the connections and disconnect them and cleaned them carefully, but ................................ nothing happens, returning to the 1st point

man, ive noticed that there is flow ( little flow i think ) ,

listen if i disconnect the minus of the 12v battery for a while does it affect the vehicle computer to reset to the default settings ??

or switch the battery safety switch OFF ?? hey ill burn the car if i couldnt solve the problem

 

after reading the original post, you understand that these FEH do not go into ev above 39 mph.

 

Saleem, try listening for the battery fans with a stethoscope on the battery housing to confirm the fans are not working when the battery is hot. If they are definitely not working you need a new battery pack most likely. You can try reflashing the TBCM if you have access to that equipment. The program could be downloaded I think but your mechanic would need to contact Fords Hotline to find out what he will need. You really need a diagnostic tool to enter "TBCM PIDs" to see the real temperature and read any battery DTCs or other Ford Hybrid DTCs to go further. Like I said originally, if the battery fans are not working you have serious problems. Not giving me DTCs is a real problem trying to help you.

Disconnecting the 12V battery after the PCM has shutdown all the relays should not help but give everything a try. Be sure you have the Key in the OFF position for 10 minutes so the PCM can shutdown the relays before disconnecting the 12V battery ground. Leave the 12V battery disconnected for at least 5 minutes for a reset of "Keep Alive Memory" (KAM).

GaryG

 

man i think i can feel some air at the back side of the battery ventilation , and when i press the odometer button and switch the key on, i can press it again and see the ( BT ) value, which is starts at almost 25c and after an 1 hour drive it becomes 44c at most and never exceeds this value, and i think its the battery temperature, right ??

Gray, is there any thermostat controlling the battery cooling ???