Focus_pilot
Posts: 14
Joined: Fri Jan 07, 2022 5:17 pm

Battery positive contactor stuck closed

Sat Jan 22, 2022 2:56 pm

I drove the car pretty hard today and when I got home to charge, I received a charging fault. When I went to turn the car on, I received the stop safely now. I check the codes and it shows Battery Contactor A stuck closed, P0AA1 and P0A95 High voltage fuse A. Anybody seen this before?

triangles
Posts: 1196
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio
Contact: Website

Re: Battery positive contactor stuck closed

Sat Jan 22, 2022 3:40 pm

Hope you are under warranty still. Ford doesn't do component level repair on the battery. They will only replace the whole battery pack.

If you are handy and competent to work on high voltage systems (ie won't electrocute yourself), you could probably put a new contactor in assuming you can find one.

Let us know how you resolve this.

Also if you haven't already, pull the safety disconnect plug behind the rear seat to power down the car. Otherwise you may kill the battery by running it too low since it cannot turn off and you cannot charge it.
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

Focus_pilot
Posts: 14
Joined: Fri Jan 07, 2022 5:17 pm

Re: Battery positive contactor stuck closed

Sat Jan 22, 2022 3:46 pm

Mine is a 2018 FFE, 35k on the mileage. I planned to have it towed to the dealer and see what happens. I am hoping it’s just a fuse.

Heima
Posts: 231
Joined: Thu Feb 21, 2019 11:46 pm

Re: Battery positive contactor stuck closed

Sun Jan 23, 2022 12:34 am

The Service Manual says this for the P0AA1:
P0AA1:00 Hybrid/EV Battery Positive Contactor Circuit Stuck Closed: No Sub Type Information A fault is indicated when the BECM is first powered ON or commanding the contactors to open and internal high voltage battery measurements indicate the positive contactor is closed while the BECM is commanding the positive contactor open. When this fault is present, the vehicle does not start, the high voltage battery does not charge and the stop safely hazard (red triangle) warning indicator is illuminated in the IPC . If this fault is cleared or repaired while the ignition is ON, the ignition must be cycled from ON to OFF and back to ON before the BECM commands the contactors to close again.

E5 CONFIRM THE HIGH VOLTAGE BATTERY FAULT
Ignition OFF.
Inspect Upper High Voltage Battery Pack C4805E and Lower High Voltage Battery Pack C4804E for:
pushed-out, loose or spread terminals and loose or frayed wire connections at terminals - install new pins or repair wires as necessary
any damaged, pinched, cut or pierced wires - repair wires
damaged or bent pins - install new terminals/pins
corrosion (install new connectors or terminals - clean module pins)
Repair any concerns found.
Connect Upper High Voltage Battery Pack C4805E .
Connect Lower High Voltage Battery Pack C4804E .
Ignition ON.
Enter the following diagnostic mode: Clear Diagnostic Trouble Codes (DTCs) - BECM .
Ignition OFF.
Ignition ON.
Enter the following diagnostic mode: Self Test - BECM .

Was the original DTC retrieved on-demand during the self test?

Yes CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a Technical Service Bulletin (TSB) exists for this concern, discontinue this test and follow Technical Service Bulletin (TSB) instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new upper and lower high voltage battery. For the upper high voltage battery,
REFER to: High Voltage Upper Battery (414-03A High Voltage Battery, Mounting and Cables, Removal and Installation).
For the lower high voltage battery, REFER to: High Voltage Lower Battery (414-03A High Voltage Battery, Mounting and Cables, Removal and Installation).
No The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.


The Service Manual says this about the P0A95:
P0A95:00 High Voltage Fuse: No Sub Type Information A fault is indicated when the BECM measures less than an expected amount of voltage at a certain internal point in the high voltage battery when module is first powered on. When this fault is present, the high voltage battery does not charge and the powertrain malfunction (wrench) warning indicator illuminates in the IPC . If this fault is cleared or repaired while the ignition is ON, the ignition must be cycled from ON to OFF and back to ON before the BECM commands the contactors to close again.
D2 VERIFY CORRECT LOWER HIGH VOLTAGE BATTERY SERVICE DISCONNECT PLUG INSTALLATION
Ignition OFF.
Depower the high voltage battery.
REFER to: High Voltage Battery Disconnect and Connect (414-03A High Voltage Battery, Mounting and Cables, General Procedures).
Remove the lower high voltage battery service disconnect plug. Inspect both sides of the connection for damage, and repair as necessary.
Install the lower high voltage battery service disconnect plug, making sure it is correctly seated.
Repower the high voltage battery, making sure the upper high voltage battery service disconnect plug is correctly seated.
REFER to: High Voltage Battery Disconnect and Connect (414-03A High Voltage Battery, Mounting and Cables, General Procedures).
Connect the diagnostic tool.
Ignition ON.
Enter the following diagnostic mode: Clear DTCs - BECM .
Ignition OFF.
Ignition ON.
Enter the following diagnostic mode: Self Test - BECM .

Is DTC P0A95:00 retrieved during the self-test?

Yes GO to D3
No The concern may have been caused by a damaged or incorrectly installed lower high voltage battery service disconnect plug. RETURN the vehicle to the customer.


D3 CHECK THE HIGH VOLTAGE FUSE FOR AN OPEN CIRCUIT
Ignition OFF.
Depower the high voltage battery.
REFER to: High Voltage Battery Disconnect and Connect (414-03A High Voltage Battery, Mounting and Cables, General Procedures).
Remove the lower high voltage battery service disconnect plug. Inspect both sides of the connection for damage, and repair as necessary.
Measure:


Positive Lead Measurement / Action Negative Lead

Lower high voltage battery service disconnect pin 1, component side
Lower high voltage battery service disconnect pin 2, component side


Is the resistance less than 3 ohms?

Yes CHECK OASIS for any applicable Technical Service Bulletins (TSBs). If a Technical Service Bulletin (TSB) exists for this concern, discontinue this test and follow Technical Service Bulletin (TSB) instructions. If no Technical Service Bulletins (TSBs) address this concern, INSTALL a new upper and lower high voltage battery. For the upper high voltage battery,
REFER to: High Voltage Upper Battery (414-03A High Voltage Battery, Mounting and Cables, Removal and Installation).
For the lower high voltage battery, REFER to: High Voltage Lower Battery (414-03A High Voltage Battery, Mounting and Cables, Removal and Installation).
No INSTALL a new lower high voltage battery service disconnect plug.

Hoping your problem is just a loose connector and loose service disconnect.

Focus_pilot
Posts: 14
Joined: Fri Jan 07, 2022 5:17 pm

Re: Battery positive contactor stuck closed

Sun Jan 23, 2022 7:52 am

Heima,

Thanks for the reply! That certainly gives me an awareness of what’s going on. I am going to have it towed tomorrow and hope for the best!

Focus_pilot
Posts: 14
Joined: Fri Jan 07, 2022 5:17 pm

Re: Battery positive contactor stuck closed

Thu Jan 27, 2022 7:09 pm

For my 2018 FFE, dealer just told me the contactor code troubleshooting has led to the battery as you guys predicted. Awaiting Ford to figure out the way ahead.

triangles
Posts: 1196
Joined: Tue Aug 16, 2011 11:40 am
Location: Toledo, Ohio
Contact: Website

Re: Battery positive contactor stuck closed

Wed Feb 02, 2022 6:10 pm

Glad you are still under warranty. Keep us updated as to how things go.
2014 Blue Candy FFE
http://www.fuelly.com/car/ford/focus/2014/triangles/303811 (since this forum doesn't allow BBcode in sigs)

Focus_pilot
Posts: 14
Joined: Fri Jan 07, 2022 5:17 pm

Re: Battery positive contactor stuck closed

Wed Feb 02, 2022 6:22 pm

My Focus was towed to the dealer last week Monday. Still waiting for them to decide on the way ahead.

dlinehan
Posts: 2
Joined: Mon Feb 07, 2022 1:24 pm

Re: Battery positive contactor stuck closed

Mon Feb 07, 2022 1:46 pm

I am glad that yours is under warranty. I have a simular problem only for mine it is "multiple contactors stuck open". My battery warranty ended one month before I took to to the dealer. They are quoting $15,500 for the battery.

I am trying to appeal this to Ford. If that does not work then I am looking for a replacement junk yard battery or trying my hand at replacing the contactors. I am confident in my ability to not get electrocuted but less confident in my ability to work on their proprietary systems.

Does anyone know if the contactors are intigrated in some board once I open the pack, are they off the shelf contactors? Ofcourse, maybe the problem is not actually the contactors which cause them to get stuck open. Where can we go for technical help?

Devin

Heima
Posts: 231
Joined: Thu Feb 21, 2019 11:46 pm

Re: Battery positive contactor stuck closed

Mon Feb 07, 2022 7:59 pm

Whats got me is how does a contactor "stick" open. Open is the normal unenergized state. Do they mean the coil inside the contactor is open? Meaning there is a break in the windings? When a contactor "sticks closed" it means it is literally welded closed. This can happen if the precharge resistor or precharge contactor fails and there is too high of potential across the contactors contacts when it closes. The inrush current is so high it melts the contacts and they weld closed. Replacing the contactors solves the immediate problem, but you also have to investigate why the precharge circuit is not functioning properly.

Those who have disassembled their HV batteries might be able to answer this question: are the contactors located behind the service panel on the LH front of the upper battery pack?

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