PHEV dead after heating, how to reboot?

[Steamrunner]

First off, I’ve spent an hour or so trying to find something already posted but just keep finding guides on resetting the BMU- by all means please point me to posts which can help!

PHEV (‘15) has been absolutely fine until this morning. Car was iced up so I popped out, turned it on, set the windscreen de mister going, went back in the house. I didn’t use the app because I can’t connect to the cars Wifi any more (it’s as if the car just drops any WiFi connections; was fine a year ago).
Anyway, went back out to the car 15 minutes later and there are all sorts of errors coming up on the dashboard, including the popular “EV system bust, stop driving, the vehicle will self destruct in 5 seconds” message. Except I wasn’t driving, obvs, what with the car being plugged in to the wall charger.

Anyhow, I can only assume that somehow, by leaving the heating on without being in the car, it’s had a strop. Handbrake is on. Now nothing at all happens when pressing the power button (foot on or off the brake).
I’ve disconnected the 12v battery in the boot.

I am sceptical that there’s an actual fault because I haven’t had so much as a warning (except tyre pressures a few months back) and it’s been otherwise fine; it was happy when I turned it on to put the heating on.

Any ideas?

 

[Craigy]

Sounds like the 12V battery is flat, recharge it (or jumpstart the car) and take it for a drive. If the car is plugged in and running the windscreen heaters I don’t think it’s actually using the traction battery, though not sure. I don’t think the car will actually get to “READY” mode while plugged in?

 

[Steamrunner]

Ok silly question- does leaving the car plugged in recharge the 12v?

That could explain it- I thought the traction battery would run the heater!

 

[Craigy]

Question to the OP, did you switch the car on with your foot on the brake?

 

[Steamrunner]

Both.

 

[greendwarf]

PHEV (‘15) has been absolutely fine until this morning. Car was iced up so I popped out, turned it on, set the windscreen de mister going, went back in the house.

When you say "turned it on" - do you mean all the way to ready to move off or just booting up so you can run accessories? If the latter then, yes, probably, flattened the 12v - even in 15mins, in frost conditions it would have been down from its best. especially if 4 years old. Too late going for ready (i.e. foot on the brake) once it had happened.

 

[Steamrunner]

Can’t remember if it was in Ready or not. Certainly sounds like 12v has gone flat, though.
Will having it plugged in charge the 12v?

 

[greendwarf]

As yours has the wifi module, I understand the 12v is topped up from main battery once a day (2pm?) but otherwise no AFAIK.

 

[Craigy]

When mine went flat I could start the car with it plugged in. Seem to remember that it would start to the standby state with no errors, then unplug and start to the Ready state. Then it will drive, and of course at this point the 12v battery is charging from the traction battery.
Mine was actually faulty but I think yours may have simply been flattened by the fans and windscreen heater, did you turn on the defrosters?
I now have a small lithium ion jump start pack which I can use to start it if the same problem happens again, with one of these you can start the car anywhere with the same issue. Only cost 30 quid or so.

 

[michael8554]

How many amps are needed to "start" the car (foot on the brake, press the button) ?

Would your average 12V battery charger attached to the jump-start terminals do the job?

 

[Craigy]

How many amps are needed to "start" the car (foot on the brake, press the button) ?

Would your average 12V battery charger attached to the jump-start terminals do the job?

Very little power is required to actually “start” the car, hence the 12v battery is pretty small. However when the voltage has dropped too low on this battery these faults occur. I’m unsure if it fails to close the contactors for the traction battery or some other test fails, but it certainly fails!
The engine is started by the traction battery when required so this isn’t an issue.

I would have thought that even the smallest jump pack is enough to start a PHEV.

 

[Steamrunner]

I left it charging for a few hours (from around 12 till 4), went back and it’s all fine now. Starts up ok, drives etc. I figured the heater would run off the traction battery but maybe it’s only if you use the app or the timer to do preheating?
I’ll have to see if I can get the WiFi to connect properly again.

Thanks for your help, lesson learned!

 

[greendwarf]

And the rise in ambient temperature would have helped

 

[michael8554]

How many amps are needed to "start" the car (foot on the brake, press the button) ?

Would your average 12V battery charger attached to the jump-start terminals do the job?

The engine is started by the traction battery when required so this isn’t an issue.

I would have thought that even the smallest jump pack is enough to start a PHEV.

???? So which is it, is the PHEV "started" by the 12V battery or the EV battery?

 

[Craigy]

How many amps are needed to "start" the car (foot on the brake, press the button) ?

Would your average 12V battery charger attached to the jump-start terminals do the job?

The engine is started by the traction battery when required so this isn’t an issue.

I would have thought that even the smallest jump pack is enough to start a PHEV.

???? So which is it, is the PHEV "started" by the 12V battery or the EV battery?

Starting the car and the engine are two totally different things as I’m sure you’re aware? To “start” the car to ready mode the contactors must be made to connect the traction battery to the drive system, the 12v battery does this.
Once you’re in ready mode and the engine is started (for whatever reason) the generator is used to start the engine from the traction battery.

 

[littlescrote]

I figured the heater would run off the traction battery but maybe it’s only if you use the app or the timer to do preheating

the heating does work off the traction battery. there's no way the 12V battery can supply the near 4kW needed as that would be (4000/12=) 333A which would need some seriously thick cables and the battery capacity of 45Ah would be used up in (45/333 = ) 0.135 hours, or 8 minutes.

 

[Tipper]

Any auxiliary item used in the car including the heater fans and heated seats will drain the 12V battery. The electric heating source and I think the heated windscreen are fed by the traction battery.

You need to get the car to full Ready mode before running any accessories in the car so that the 12V battery is charged from the traction battery. It's a small battery and won't last long without constant charging.

Interestingly I didn't think that my early 2015 will 'start' on the button if still plugged in! I certainly get a 'plugged in' error message.

 

[Craigy]

And the OP was talking about defrost I think, the windscreen heater both front and back probably run off the 12V battery.

I seem to remember when I had this problem, the car will start into standby mode plugged in, then once unplugged will go to ready mode (when you push the button again). This appeared to allow me to start the car even with a flat 12V battery.

 

[elm70]

First off, I’ve spent an hour or so trying to find something already posted but just keep finding guides on resetting the BMU- by all means please point me to posts which can help!

PHEV (‘15) has been absolutely fine until this morning. Car was iced up so I popped out, turned it on, set the windscreen de mister going, went back in the house. I didn’t use the app because I can’t connect to the cars Wifi any more (it’s as if the car just drops any WiFi connections; was fine a year ago).
Anyway, went back out to the car 15 minutes later and there are all sorts of errors coming up on the dashboard, including the popular “EV system bust, stop driving, the vehicle will self destruct in 5 seconds” message. Except I wasn’t driving, obvs, what with the car being plugged in to the wall charger.

Anyhow, I can only assume that somehow, by leaving the heating on without being in the car, it’s had a strop. Handbrake is on. Now nothing at all happens when pressing the power button (foot on or off the brake).
I’ve disconnected the 12v battery in the boot.

I am sceptical that there’s an actual fault because I haven’t had so much as a warning (except tyre pressures a few months back) and it’s been otherwise fine; it was happy when I turned it on to put the heating on.

Any ideas?

As said ... I think ... 12V has gone flat.

You left the car in "stand by" mode, since it was plugged in (when plug in it can't go in ready mode)

In this condition all 12v system is up and potentially consuming a lot of amps, if you have some defrost or heated seat .. but since it was in stand by , the main battery was not charging the 12v battery as does normally when is in ready mode

Replace the 12v battery or charge it properly and your PHEV should get back alive