Disco 4 (LR4) Charging system fault

sierrafery · Nov 14, 2023

Respect for your update and i'm sincerely glad it's sorted for you but i'm not glad at all when i see mechanics who are simply lucky to fix things then telling "stories" to the customers cos there is no such thing as "battery monitor sensor" on a D4, if it's about "battery monitoring system"(BMS) it's also false as the BMS is on the battery negative lead and there is no wire which goes through the plenum to it... in reality there are two complex modules involved in the charging system which might be connected to a wire which goes through the plenum but they can hardly be named "sensor":
1. the GWM(gateway module) behind the instrument pack
2. the QCCM (quiescent current control module) behind the glovebox

I just wanted to make it clear for those who will try to find a similar fault to not search for a "sensor" wire in the plenum but a wire which goes to one of those modules eventually

gstuart · Nov 15, 2023

sierrafery said:
Respect for your update and i'm sincerely glad it's sorted for you but i'm not glad at all when i see mechanics who are simply lucky to fix things then telling "stories" to the customers cos there is no such thing as "battery monitor sensor" on a D4, if it's about "battery monitoring system"(BMS) it's also false as the BMS is on the battery negative lead and there is no wire which goes through the plenum to it... in reality there are two complex modules involved in the charging system which might be connected to a wire which goes through the plenum but they can hardly be named "sensor":
1. the GWM(gateway module) behind the instrument pack
2. the QCCM (quiescent current control module) behind the glovebox

I just wanted to make it clear for those who will try to find a similar fault to not search for a "sensor" wire in the plenum but a wire which goes to one of those modules eventually

hi mate

may I also add bless u for such a fantastic explanation , I must confess I always thought a plenum was simply a chamber so was confused with that being mentioned by the mechanic

indeed also understood there’s the BMS module which has just one wire connected to the central junction box and the other battery monitor on the negative battery post

thks again as I know ur considerably more knowledgeable when it comes to the electronics side of things

hope this also finds u well mate

DanB88 · Feb 5, 2024

benh999 said:
So we have solved the “charging system fault” message on the dashboard..

My mechanics words were :-

The charging fault was a corroded wire in the plenum that provides the power to the battery monitor sensor

So if anyone else is having this message this is worth a look

I’ve been having this exact same problem for the last year, sometimes all fine then the next minute I have a charge fault flash up. Reading the charge voltage on the iid tool I get 14.7 volts then down to 14.5 and will hold for a while before fluctuating between 12- 13.7v I’ve been through everything, new battery new alternator, BMS sensor and even a gateway module as I was advised it my be that.
Any idea where I’d find this wire the ‘plenum’ seems quite vague. At my whits end.

Disco 4 (LR4) Charging system fault

sierrafery

Well-Known Member

gstuart

D3 Grandad

DanB88

New Member

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