Unfortunately, Ford dealers are clueless when it comes to electric or hybrid cars and Ford will not honor the 8-year warrantee on hybrid batteries that they promise.
I had the wrench symbol followed by the check engine light (code: P0B24, Hybrid Battery "A" Voltage Unstable) earlier this year on my 2013 C-Max Energi, which still has less than 50k miles total (~25k EV). The problem fixed itself, I cleared the code myself, and it did not come back for many months. But because my EV mileage had dropped from 22 to 10 miles in less than 7 years I took the car to Ford anyway to have the hybrid battery checked out and hoped for a replacement. They were completely clueless: They didn't even know how to measure the battery's capacity. They then replaced the charging module and wiring harness despite nothing being wrong with them. They admitted that the battery had lost capacity, but claimed that it was normal and stated that Ford would not replace hybrid batteries because of capacity loss, no matter how severe. I picked up the car on Tuesday (after they messed around with it for more than 6 weeks!) and noticed immediately that I don't really have an EV vehicle anymore. The engine is now almost constantly running in parallel with the EV motor, despite the battery having up to 10 EV miles left. First, I thought they activated the "EV later" mode, but 'no', this happens in "EV" and "AUTO" mode. This morning, after charging overnight, I had only 7 EV miles. The engine kicked in immediately, no EV energy at all used for the first 4 miles, then both electric motor and engine ran in parallel and the kW usage ramped up, as if there was a short or something, and at 1.2 kW (3 EV miles left) the wrench light came on with the message to "check the user manual". At that point, the car stopped being a hybrid, no more EV, no more regenerative breaking, just an old fashioned vehicle with a combustion engine. I wish now I had never taken my C-Max to Ford and just lived with the reduced 10 miles EV range. Ford messed it up so badly that it can't even be called a hybrid anymore, let alone a plug-in hybrid. And I'm sure they find nothing wrong with it if I take it back to Ford, or they would have to replace the hybrid battery, which they will never do.
