Battery temperature sensor erratic

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Kasputis

Member
Joined
Aug 19, 2021
Messages
21
Hello friends. My FFE threw SSN while driving highway.
I get codes:
P0C91 - Hybrid/EV Battery Temperature Sensor 'J' Circuit Intermittent/Erratic
P0C8C - Hybrid/EV Battery Temperature Sensor 'I' Circuit Intermittent/Erratic
P0AC9 - Hybrid/EV Battery Temperature Sensor 'B' Circuit Intermittent/Erratic
P0AA2 - Hybrid/EV Battery Positive Contactor 'A' Circuit Stuck Open

And when i try to start the car, contactors tries to close for a second, then opens and i hear SSN chime.

The question is: maybe someone is familiar with these temperature sensors. I guess they are two thin black wires going in between cell puoch. But don't know how to locate correct ones.
1000003745.jpg
 
One of honorable members had great idea to disconnect sensors one by one and scan for new DTC's, so to make a map whitch sensor is assigned to what letter. But after i hooked everything to car temperature sensors errors went away and all that's left is positive contactor A stuck open. So now the problem is clear, but new problem arises where to get this type contactor in europe.

I can get contactors from mach-e, but their coils works without economization. (Constant 12v instead of pwm control), so i assume they will not work in ffe
1000003762.jpg
 
I was going to suggest the same method of disconnecting and checking to isolate them. There's pretty much no documentation for the battery as it's not a "serviceable" part.

Pretty sure others have found the contactors before and posted the part number.
 
Service manual says "try to erase DTC's, if they come back: replace battery" :D Electrical schematics ends where battery lid starts.

Yes, contactor model is known, it's TE connectivity EVC500. But all sellers have it with external economizer attached. I will try to remove it and solder my plug straight on coil wires. 1000003786.jpg
 
You should ask ajbessinger on here. He posted about his teardown on the Focus Electric Facebook page, and I believe he is utilizing a better brand of contactors. He mentions it in one of his posts on there.
One of honorable members had great idea to disconnect sensors one by one and scan for new DTC's, so to make a map whitch sensor is assigned to what letter. But after i hooked everything to car temperature sensors errors went away and all that's left is positive contactor A stuck open. So now the problem is clear, but new problem arises where to get this type contactor in europe.

I can get contactors from mach-e, but their coils works without economization. (Constant 12v instead of pwm control), so i assume they will not work in ffe
View attachment 102
 
I saw his videos on youtube but don't remenber him talking about contactors upgrade. Thanks for sharing!
 
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