Focus Mk4 Rear Windscreen Demister Issue

[GermanWolf]

Got a Mk4 Focus, bought August 2019. It has, of course, had the Emergency Call System Malfunction Error, but now in the cooler weather I've noticed the rear windscreen no longer clears when the setting is turned on.

2nd unique issue I've had in 4 months of owning the car.

Anyone else had this?

[Ams]

Hi GermanWolf,

 

I’ve noticed this issue as well. I noticed that the bottom 4 lines aren’t clearing as quickly as the rest of the screen. I initially thought there might be connection issue but then I ordered a tester from amazon. On tester i’ve noticed that power reduces further I move it to either sides of the screen. Maybe normal but I’ll keep an eye on it. 

[GermanWolf]

7 hours ago, Ams said:

Hi GermanWolf,

 

I’ve noticed this issue as well. I noticed that the bottom 4 lines aren’t clearing as quickly as the rest of the screen. I initially thought there might be connection issue but then I ordered a tester from Amazon. On tester i’ve noticed that power reduces further I move it to either sides of the screen. Maybe normal but I’ll keep an eye on it. 

Thanks for the response. The issue is, it's worked before and cleared fairly quickly. But your description of the bottom 4 lines not clearing is the same as I'm noticing now in the past week or so. Quite frustrating really! 

I'll keep an eye out too.

[Wood Gnome]

Also having the same problem, with the rear and the front heated windows.

Could it be the GEM module playing up again

Thanks

Paul

[rayferry]

I just had this problem yesterday front and rear screens not working for a second time.

The first time this happened about 10 days ago they started to work after I had driven about 150 miles we had stopped for something to eat, returning to the car both screens worked.

I found a report of a Fiesta with the same problem and the dealer replaced the battery.

This would explain why after a long drive and the battery fully charged the screens work again.

I would guess the ECU is shutting down high current devices

[Wood Gnome]

I will charge my battery over the weekend, see if it helps, cant hurt to try.

Its a real pain, would be nice to be able to monitor the battery health as you drive, it must be possible, maybe a on OBD linked to phone and mirrored to sync display.

 

Paul

[pcaouolte]

Forscan on a phone with a wifi obd2 connector can monitor battery state of charge while you drive.

[Comares2001]

Just plug a battery monitor into 12v socket as a number of us have done. It gives you a good idea and shows how the charge voltage is adjusted while driving .

[Tizer]

12 hours ago, Wood Gnome said:

I will charge my battery over the weekend, see if it helps, cant hurt to try.

Its a real pain, would be nice to be able to monitor the battery health as you drive, it must be possible, maybe a on OBD linked to phone and mirrored to sync display.

 

Paul

 

39 minutes ago, pcaouolte said:

Forscan on a phone with a wifi obd2 connector can monitor battery state of charge while you drive.

To expand on the above you can also monitor the charging mode, current and voltage as well as some other things. 

There are about 20 PID's for why stop/start has been disabled and there are probably some for the Heated screens also.

I don't think you can mirror to your Sync screen but you can record your journeys. 

A lot of the problems that people are having are because they don't understand how the system needs to work to appease the greens and comply with the legislation. 

[rayferry]

12 hours ago, Wood Gnome said:

I will charge my battery over the weekend, see if it helps, cant hurt to try.

Its a real pain, would be nice to be able to monitor the battery health as you drive, it must be possible, maybe a on OBD linked to phone and mirrored to sync display.

 

Paul

Can you let us know how it goes as my car is not booked into the dealer until Tuesday, thanks.

No wonder this vehicle has not been released in the US they would be facing multiple class action lawsuits.

[Wood Gnome]

So been running around most of the weekend without using any heated seats or windows etc and auto stop start set to off. Also had an OBD dongle in use and with the Torque app was able to monitor the charge and battery state. I was going to  charge the battery but it was showing plus 14volts when not in use, so didnt want to cook the thing ( I sure they will know if its been charged🤣).

Tomorrow morning at 6.20am will be the test, heated rear will be on, also has anybody whos had this issue with the heated screens did you try the seats, ill try this tomorrow if the screens dont work, i mean they shouldn't work should they, that would be comfort over safety ?? Just a thought🤔  

Also might be a thing to note, i had the SOS error thats been on another thread and they are stating battery issues, i pulled fuse 11 out as per the thread and it did solve it but others are having no joy with that.  

Back Monday evening with and update 

 

Paul

 

[Wino]

Should both the front and rear heated screens work at the same time like they did on the MK 3 ? 

When we had the frost last week or so I put the rear on first and then the front on after whilst the engine was running. The rear was cleared by the time id got the scraper out of the boot to clear the headlights but nothing on the front until the rear was switched off. Im hoping its normal practice in the MK4 to protect the system unlike in other Focus.

[gillyallan]

Weirdly on the 3.5 if it's below temp. When frost light is on. The back and front come on themselves when you start up. The buttons seem pointless other than the odd time rear is misted.

[Wood Gnome]

Mild morning no need for heated screens 

[rayferry]

I had my Focus into the dealer this morning my battery was less than the 80% capacity this I think is the maximum charge level.

They say by design the system will turn off high current devices like the front and rear screen heaters.

They said they would ask other Ford dealers if any of them had changed the battery for a higher capacity to see if that has helped.

My battery is a 60ah 600 CCA. On another thread (Emergency Call System Malfunction, page 3) the owner changed his battery for a 70ah 760 CCA and all of his problems have gone away

 

 

[rayferry]

No feedback from the dealer as yet, but thinking of the "by design" feature Ford are selling a car that cannot run all the factory installed options when driving normally at say 30 MPH 1600 revs or so, totally bonkers IMO. 

[Sashus]

Does anyone know is this part of rear windscreen is demister or part of radio antenna? It does not defrost this part of the windscreen. It seems that rear windscreen has two parts of defrosters, one large part that is below this marked space (that part works fine) and a small section with four separate wires that does not work.