Could do with some advice.

I have a 2018 Ford Focus Zetec TDCI, it's recently had some issues when driving that the electrics cut out, leaving no dashboard, indicators, AC, etc. The car goes into reduced power mode too. I would turn the car off, try to start and it's dead.

I've noticed that this sometimes happens when it rains but not always. I took it to Ford which diagnosed a problem with the Battery Back Sounder, which was replaced back in March this year and for a few months it's been fine.

Then again last weekend I had some issues where the dash would go bonkers, flashing up warnings like hill assist start errors and ESC service required. Again turning the car off, trying to restart and it's dead.

I took it for a new battery. The indy mechanics who inspected the fuse box in the passenger footwell took the wire loom connectors off then reconnected and the car started fine.

But with similar issues about 5 mins later, dead dash etc. Until I take off the loom connectors then reconnect.

Has anyone had similar problems or found a solution? 

Errors on Dash - 

 

Is the car manual or automatic ?

Manual I'm guessing because no gear position on the IC, but given the bizarre behavior I thought I'd check.

Yes it's a UK manual model. 

I think I'd be tempted to put a new, better, battery on and reset the BMS, see if that cures it

2 hours ago, DaveT70 said:

I think I'd be tempted to put a new, better, battery on and reset the BMS, see if that cures it

I had the battery replaced, I've tried to reset the BMS using the steps (fog light button & hazard button) but no joy. 

41 minutes ago, Balron_uk said:

I had the battery replaced, I've tried to reset the BMS using the steps (fog light button & hazard button) but no joy. 

Get yourself set up on FORScan and see if you've got any DTCs

Fully charge battery and then reset BMS using FORScan

Don't buy the cheap chinese ELM327 for a MK4 get the V-Linker or the OBDLink-EX

12 hours ago, Balron_uk said:

I've tried to reset the BMS using the steps (fog light button & hazard button) but no joy. 

That's the wrong BMS reset process for your car.

You need to use method 2. Video posted below

On 3/29/2023 at 8:14 PM, unofix said:

How to reset the BMS method 2                                                                         Search Tag: BMS2

 

 

So I've used an OBD code scanner which has flagged up a "P1934 Manufacturer Control" code. 

Some mention of a Vehicle Speed Sensor on another forum?

Others mentioning that it's a code in the transmission category?

I've reset my BMS too. I ran the car for about 10 mins and the car did still throw up some dashboard errors - 

Auto Hold Error/ ESC Service Required but I didn't lose power completely. I restarted the car and it ran fine for another 10 minute.

I'm on the verge of selling it. Either try my luck and sell it as error-free and see if it behaves in the assessment or sell it as faulty/ for parts.

I don't want to keep throwing money at it when I'm not 100% on the problem.

Some more digging into the P1934 code suggests a problem with the "wire harness break actuator assembly skid control ECU" which I guess is ABS wiring?

Do you think that could be related to the Auto Hold & ESC errors?

Maybe a problem with the wiring causing the main power to the instrument cluster to fail?

1 minute ago, Balron_uk said:

"wire harness break actuator assembly skid control ECU" which I guess is ABS wiring?

I don't know what generic code reader you are using, but need to be using FORScan and a vLinker FS cable to get the Ford specific DTC's.

I'd suspect a loose or poorly fitted Mega Fuse in the Battery Junction Box.