Battery Temp Sensor Intermittent/Erratic

[breeves002]

I was looking through FORScan on the car for the first time in a while and noticed I had 4 codes.

3 were in the BECM:
P0AC9 - Hybrid Battery Temperature Sensor B Circuit Intermittent/Erratic
P0C8C - Hybrid Battery Temperature Sensor 1 Circuit Intermittent/Erratic
P0C91 - Hybrid Battery Temperature Sensor 2 Circuit Intermittent/Erratic

I also had P0C4A in the PCM which I have seen before for "Hybrid Battery Pack Coolant Pump Control Performance". The heater coolant pump was replaced last year under warranty when it failed. Same code was there then.

I'm not sure what would causes these. No Freeze Frame data with them. I thought about clearing and seeing if they came back but if there's some reason I need to take it in let me know. Its under the ESP extended warranty with $0 deductible so as long as there is something to repair its free for me to bring it in. Otherwise I'll clear the codes and see if they come back.

I also had a U0100 in the ABS module for lost communication with ECM/PCM but I don't think that is anything important.

 

[sefs]

Breeves,

Did you have the recall work performed on the lower battery, getting the connector checked out for cracking and the snow shield installed?

 

[Guest]

Is the coolant level correct? Ive seen posts from people who had battery temp problems only to discover that the coolant level was not up to par. All air had not been purged from some recent service that required the coolant system to come apart and be drained. Topping it off solved their problems.

 

[breeves002]

I did have the recall work done. Car is up to date on recall work. The connector was fine as far as I know.

I will check the coolant in the morning. Good tip.

 

[breeves002]

Update: Coolant level was right on the low line today while cold. I don't think I'd consider that low coolant. I'm going to clear the codes and see if they come back.

 

[breeves002]

Another update. I didn't drive the car on Friday and went to drive it this evening and the 12v battery was dead... I jumped it and it seemed fine but that was weird to me. Wondering if it going bad has anything to do with this issue. My guess is no though. I'll get a new battery soon.

Its crazy how fast these cars eat batteries.

 

[Guest]

Another update. I didn't drive the car on Friday and went to drive it this evening and the 12v battery was dead... I jumped it and it seemed fine but that was weird to me. Wondering if it going bad has anything to do with this issue. My guess is no though. I'll get a new battery soon.

Its crazy how fast these cars eat batteries.

It would not make much sense for that to be causing your codes. But, it would not surprise me if it did. A failing 12v seems to cause all sorts of havoc on these cars.

 

[davideos]

Could be the battery, who knows. The 12V issues has created some odd issues. Go ahead and replace and see how it goes.

 

[breeves002]

Battery is fine. IDK what caused it to die. I know there's a TSB on randomly dying batteries that came out a few years ago. Updating the GWM or some other module is recommended. There's also a TSB on the P0C4A code saying air gets trapped in the cooling system or coolant level low (I checked).

I let the car sit 3 days since I had a dealer loaner while my Mustang was being fixed and the battery is still fine. Drove it around the block tonight. Will drive it to work tomorrow.

 

[lmlaster]

I read your post. My car is having crazy problems during 90+ heat. My dealer checked the 12V battery and said it was good. Any guesses? They've had my car for 3 weeks now and waiting on Ford Corporate to interpret what the codes mean

Here is my original post
http://www.myfocuselectric.com/forum/viewtopic.php?t=4860

2015 Ford Focus Electric
NWIndiana White Lightening