The factory fitted battery in my 2014 Focus Titanium X died last week, so I had to replace it. I ordered a new battery from Halfords, who came and fitted it at my home, confirming verbally that it was the correct model (Start Stop, EFB100) before he did anything. The battery was replaced and the car seemed to be OK. However, the second time the car started (about a day later), the Check Engine light came on and won't go away. I contacted Halfords, who sent me to their local National Tyres and Autocare centre to run a diagnostic. This produced 4 pages of electrical errors, covering just about every electronic component in the car. Prior to this, apart from a dead battery, there was nothing wrong with it.

The guy at National has never seen this before and doesn't have an answer. He also wasn't able to reset any of the persistent errors through their system, leaving me to try and find an answer. I've looked on Google and found a number of similar issues, all seemingly in need of a Battery Management System reset, suggesting that I get hold of a copy of FORScan software and an adaptor to connect to the car and reset everything. However, apart from not knowing what I'm doing, I've also rung a local auto electrician, who reckons there shouldn't be any need to do anything apart from physically taking the dead battery out and replace it with the new one, which suggets that the BSM reset may be a red herring.

He's suggested I take it down for a £100 diagnostic, which probably won't give me anything more than the National Tyres diagnostic. My local Ford dealer wants £130 for a similar diagnostic and is unable to offer technical advice without it. I've already forked out £200 for what I hoped would be a simple battery replacement, but apart from allowing the car to start, it seems to have created more problems.

Can anyone help or offer advice on what to do next? I can add the diagnostic results if they would be of use...

You can reset the BMS easily yourself.  It does need resetting on Fords of this era.

There is a sequence using the fog light switch and hazard switch.  I can't remember the exact sequence but it should be easy to find on YouTube.

Thanks for the reply. I've tried about 5 different versions of those resets from YouTube. All get the battery and engine lights flashing, but the engine light stays on once I start the car up.

Have you looked at the battery to make sure it’s the model you are expecting? It should be an EFB. 
 

You will have to get the codes read and post them or we are just guessing. You can use Forscan and a low cost adapter wit a laptop if you want to scan yourself. It’s usually better than generic readers anyway. 

Hi Alex, thanks for your reply. I've attached all of the codes sent to me by the National Tyres after they ran their diagnostic (these are photos of the screen, so there will be duplication as it scrolled down). Some of the items listed, e.g. lights and wipers are all working correctly, however, there are other things that I don't know about as they're not obvious what they are/do.

I had no problems before the battery was changed, which I've checked and it is the right one (Halfords EFB100 Start Stop Car Battery). One thing I haven't done yet is removed all of the coverings around the battery terminals to check that the cables have been attached properly, but I'd have thought that would stop the car from starting if that was the case.

The guy from National Tyres couldn't clear any of these errors. the only thing he was able to do was turn the Check Engine light off, until the next time I started the car when it lit up again.

14 minutes ago, MikeWJ said:

The guy from National Tyres couldn't clear any of these errors. the only thing he was able to do was turn the Check Engine light off, until the next time I started the car when it lit up again.

I've seen similar before, caused by a messy battery change.

What I mean is that the battery leads were not quickly and decisively connected to the terminals, instead the leads were touched and retouched to the terminals causing many voltage transients through the vehicles electrical system.

If you firstly disconnect the negative battery terminal for 20 minutes, and then reconnect it. Wait a further 5 minutes before doing anything. Then you need to use FORScan to clear all the erroneous codes. A general purpose generic code reader is unlikely to be able to do this.

 

You migh struggle to get the EML off without clearing all the DTCs then seeing what comes back.