Member Since: 04 Apr 2007
Location: Norfolk
Posts: 180
Generator charging failure warning
The D4 has been left for 3 weeks.
On starting this morning I got a red triangle and red battery symbol along with a “generator charging fault” warning on the between the speedo and rev counter. The stop-start light is also on.
I have connected the IID tool and got the following faults.
I have driven about 30 miles and the faults won’t clear.
The second battery is only 6 weeks old. The main battery is about 3 years old. The voltage with the engine running is 13.5v at the terminals on the main battery but only 12.6v on the small battery.
The main battery drops to 12v - 12.2v when engine stopped but starts the car ok. The small battery stayed at 12.6 with engine off.
Is it worth trying a new main battery first?Disco 4
Burstner motorhome
BMW 225e (only 1/2 way to electric)
23rd Nov 2022 1:02 pm
Gary_P
Member Since: 03 May 2016
Location: Kent
Posts: 1656
I’m wondering if those errors are indicative of Battery Monitoring system module has failed. No experience of this, but remember reading that the failure of stop start with a fault light can be caused by this module failing.
Good luck sorting.Gary
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Discovery 4 HSE 2016MY
23rd Nov 2022 1:06 pm
Flatlander
Member Since: 20 Jul 2015
Location: Here
Posts: 575
The generator defaults to a low charge voltage if it loses the LIN connection to the PCM, check that and the LIN & power connection to the BCM. Its not your starter battery at fault.
LIN connections will fluctuate around 9VDC, its actually more like a PWM signal but if you're getting somewhere around 9VDC then you can assume you're getting a connection.
23rd Nov 2022 3:31 pm
sailormike
Member Since: 04 Apr 2007
Location: Norfolk
Posts: 180
Thanks for the reply Flatlander, in depth fault finding on this sounds a bit out of my league.
The car is booked into have the seven year service the week after next and gearbox flush. Hopefully it will be ok to use until then obviously without the stop/start working.
With the generator operating on a reduced output (I’m getting a fairly constant 13.5v) I will not use electric seats, screens etc to save load.
I do however have to do a couple of long trips this coming week, fingers crossed it will be ok as I can’t fit everything in the BMW.Disco 4
Burstner motorhome
BMW 225e (only 1/2 way to electric)
24th Nov 2022 8:00 am
Flatlander
Member Since: 20 Jul 2015
Location: Here
Posts: 575
It may be worth trying a battery disconnect first, leave the bonnet open, ignition on, ignition off, key out and close the door. Leave alone for 30 mins, disconnect the battery (either pos. or neg., doesn't matter) for a few minutes. When you reconnect, try to avoid arcing as you put the terminal back on. Might not have any effect but its worth a try.
24th Nov 2022 2:49 pm
sailormike
Member Since: 04 Apr 2007
Location: Norfolk
Posts: 180
The car is back at the Independent again as they are trying to find the problem. The battery monitoring unit and the start stop power supply module have been changed previously along with the wiring checked.
The car has been plugged into the LR diagnostic kit and looked at by Land Rover technical support. They have suggested “try another alternator” which sounds like they are not sure what is wrong.
Since first posting I have realised that the heated screens, seats and steering wheel are not working, the switch lights up but nothing happens.
Also when plugging in the GAP IID tool and trying to get live readings a lot of electrical charging type readings are N/A see photo.
I’ll see what happens when the new alternator arrives,two wrong ones have turned up at the Indy so far. I’m getting frustrated with it now but would welcome any thoughts!Disco 4
Burstner motorhome
BMW 225e (only 1/2 way to electric)
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