Member Since: 20 Jan 2018
Location: Warwickshire
Posts: 141
BCM problem?
Just had a few issues which started with the entertainments system going off and restarting constantly.
Turned around and came straight back home and I realised I had no indicators and probably no other lights. Engine running OK and all things displayed except radio status and outside temp.
Switched the ignition off and waited a couple of minutes before retrying - got a whole load of errors and systems not available and then wouldn't start - no key, even with the key under the steering column.
Did a hard reset and got everything back and the car started but the entertainment system was back to its continuous reseting, indicators not working properly etc.
Ignition off - wouldn't start so another hard reset.
This time everything came back ok, but, for how long?
BCM is my guess - what's the general consensus?
That might likely also explain the problems I've had with voltage issues (and the aux heater not running for more than a few minutes) even after a battery change. Still not sure if the alternator is having issues though, but voltages seem to be running up at 14.7V.
Any ideas?
Thanks!Current : Discovery 4 HSE (2012 spec)
Current : BMW Z4 20i MSport
Current : BWM Z4 3.0SI Sport Auto
Previous : Freelander 2 HSE
24th Mar 2018 6:01 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72774
What’s the voltage on the battery, without the engine running? Alternator is running a bit high, could be working hard to fill an ailing battery.
24th Mar 2018 6:11 pm
Redline
Member Since: 20 Jan 2018
Location: Warwickshire
Posts: 141
Voltage - thats where is getting odd.
12.5V to 12.7V although its dropping to 12.3/12.4V
It will come back up a bit. I was expecting a steady decline in voltage but it's dropping 0.3V over a few hours.
After switching off it decays to 13V and then down to 12.7V and stabilises over a minute or so. By the end of the day parked at work it drops to 12.4V and down to 12.3V when it was freezing outside.
I was expecting a resting voltage around 12.6V on a new fully charged battery after everything had switched off.
Borrowed a current clamp for a few minutes yesterday and the alternator was supplying 58A with the heated screens switched and at idle then dropping down to 5-6A running on idle no other loads except usual systems. Just what you'd expect.
Switched off but with the aux heater running it was taking 14.5A at 12.2V on the battery terminals.
We did get something odd when the ignition was off. There appeared to be current flowing from the battery towards the starter/alternator. May not have had the current clamp on properly though or other rf interfering with the reading.
The odd thing is that when it was cold and the car starts the heated screens automatically, the voltage drops to 9V while starting but only climbs to 11V or so and won't climb even with revs. Switch the screens off and voltage climbs to 14.7V to 15V. when run for for a few minutes and then put the screens back on, voltage drops for a moment and the climbs back to 14.7V at idle.
I really don't know if the two issues are from the same cause or the alternator is on its way out and I now have another problem.Current : Discovery 4 HSE (2012 spec)
Current : BMW Z4 20i MSport
Current : BWM Z4 3.0SI Sport Auto
Previous : Freelander 2 HSE
24th Mar 2018 6:27 pm
Redline
Member Since: 20 Jan 2018
Location: Warwickshire
Posts: 141
BTW - 2nd brand new battery in two weeks.
Thought the original replacement might be faulty but it load tested fine when it came off.
Put a 2nd new battery on just 10 days ago.
Bosch S4 95A battery - nothing cheap and nasty.Current : Discovery 4 HSE (2012 spec)
Current : BMW Z4 20i MSport
Current : BWM Z4 3.0SI Sport Auto
Previous : Freelander 2 HSE
24th Mar 2018 6:29 pm
Redline
Member Since: 20 Jan 2018
Location: Warwickshire
Posts: 141
Also - the voltage was still 14.1V (just glanced at the meter just to check but it didn't register as odd) when everything was on the fritz.Current : Discovery 4 HSE (2012 spec)
Current : BMW Z4 20i MSport
Current : BWM Z4 3.0SI Sport Auto
Previous : Freelander 2 HSE
24th Mar 2018 6:39 pm
JonM
Member Since: 24 May 2012
Location: North Yorkshire
Posts: 1236
Did you reset the BMS when you changed the battery? Have you set the CCF to the correct setting for the battery you're using? Did you fully charge the battery before fitting it?MY2022 D5 HSE D300 - with extra nice bits added
MY2019 D5 HSE 3.0 SDV6 - sold to a dealer for a crazy price! - So good I bought another!
MY2012 D4 HSE 3.0 SDV6 - retired to a new home
24th Mar 2018 8:03 pm
Redline
Member Since: 20 Jan 2018
Location: Warwickshire
Posts: 141
My Indy did the change. I'll ask him about the reset. While he isn't a LR specialist he's pretty good and sees lots of D3/4s. What is that and what does it do?
No ideas about CCF. Again - I'll ask him. Again - what is that and what does it do?
Battery was fully charged.Current : Discovery 4 HSE (2012 spec)
Current : BMW Z4 20i MSport
Current : BWM Z4 3.0SI Sport Auto
Previous : Freelander 2 HSE
24th Mar 2018 10:08 pm
JonM
Member Since: 24 May 2012
Location: North Yorkshire
Posts: 1236
The CCF has different options for different types of battery. The BCM will get confused if the battery fitted has different characteristics to the one it expects.
A BMS reset tells the system to forget what it has already learnt about the old battery and learn the characteristics of the new one.MY2022 D5 HSE D300 - with extra nice bits added
MY2019 D5 HSE 3.0 SDV6 - sold to a dealer for a crazy price! - So good I bought another!
MY2012 D4 HSE 3.0 SDV6 - retired to a new home
24th Mar 2018 10:13 pm
Redline
Member Since: 20 Jan 2018
Location: Warwickshire
Posts: 141
The battery replaced the original LR 95AH 950CCA with a Bosch 95AH 800CCA. Both 6 cell x 2.2V lead acid. Apart from the lower CCA was same spec.
What parameters does the CCF manage?
Would there be any CCA changes needed for that exchange?
The second replacement battery was an identical to the first.
The old battery was completely shot. Dead - Zilch except for the battery warning light.
Had RAC call out- got it started, charged for an hour and enough charge for another restart to go for the battery change.
Is the BCM clever enough or dumb to think the new battery is a poorly old battery?
Have also charged both new batteries overnight with an CTech MX5.Was reading 12.75V after charging.Current : Discovery 4 HSE (2012 spec)
Current : BMW Z4 20i MSport
Current : BWM Z4 3.0SI Sport Auto
Previous : Freelander 2 HSE
24th Mar 2018 10:30 pm
JonM
Member Since: 24 May 2012
Location: North Yorkshire
Posts: 1236
The original battery on 2012 D4s was a standard lead acid type. This was inadequate and LR rep!aced them under warranty with AGM type. Mine was replaced but after about 5 years it started to deteriorate and whilst the car was starting reliably, it had various electronic gremlins. A new Exide AGM battery with a BMS reset solved the problem.
There are various battery options in the CCF it needs to be set to match the battery fitted. If you had a 800CCA battey fitted, it was probably inadequate when the D4 really needs a 950 AGM. Even worse, if the car still thought it had the original type of battery, the BMS was probably getting very confused.
I'm no expert, but I'd put a fully charged AGM battery in, make sure the CCF is programmed to expect this battery, then do a BMS reset.MY2022 D5 HSE D300 - with extra nice bits added
MY2019 D5 HSE 3.0 SDV6 - sold to a dealer for a crazy price! - So good I bought another!
MY2012 D4 HSE 3.0 SDV6 - retired to a new home
24th Mar 2018 10:56 pm
Redline
Member Since: 20 Jan 2018
Location: Warwickshire
Posts: 141
OK - See what you're saying.
Still - even on a battery charged to a point where its rest voltage is 12.59V, the webasto unit will only run for a few minutes.
Why when the alternator is supplying both current and voltage does the electronics throw a benny?
If the voltage was low, I could see that being a problem, unless the system is seeing a voltage lower than it actually is and starts shutting things down?
Does the BMS measure both voltage and current at the battery (and hence the internal resistance of the battery)?
A 950CCA battery will have a lower internal resistance than an 880CCA. So, is the system increasing alternator voltage output to compensate for the battery because it thinks it has different characteristics?
What does the CCF settings tell the system about the battery and how is it interpreted?
New batteries need a few cycles before they accept full charge too.
Who thought at 12V battery could be so complicated?Current : Discovery 4 HSE (2012 spec)
Current : BMW Z4 20i MSport
Current : BWM Z4 3.0SI Sport Auto
Previous : Freelander 2 HSE
24th Mar 2018 11:57 pm
JonM
Member Since: 24 May 2012
Location: North Yorkshire
Posts: 1236
Quote:
Still - even on a battery charged to a point where its rest voltage is 12.59V, the webasto unit will only run for a few minutes.
That was the problem I had and why LR changed mine to an AGM under warranty.
As for the rest....your questions have exceeded the limit of my knowledge...where is Robbie when you need him? MY2022 D5 HSE D300 - with extra nice bits added
MY2019 D5 HSE 3.0 SDV6 - sold to a dealer for a crazy price! - So good I bought another!
MY2012 D4 HSE 3.0 SDV6 - retired to a new home
25th Mar 2018 12:02 am
Redline
Member Since: 20 Jan 2018
Location: Warwickshire
Posts: 141
Haha - Me too.
Think the next step is find a specialist and do a deep read of the codes.
I could understand one issue can cause many problems - but, the observed measurements don't stack up with what's happening.
Could be a number of completely un-related faults though.
Anybody local to North Warks got an IIDTool to do a read of what I've got?Current : Discovery 4 HSE (2012 spec)
Current : BMW Z4 20i MSport
Current : BWM Z4 3.0SI Sport Auto
Previous : Freelander 2 HSE
25th Mar 2018 12:21 am
Redline
Member Since: 20 Jan 2018
Location: Warwickshire
Posts: 141
Cautiously took a test drive today and no issues.
Am hoping it’s just a BCS reset that’s neededCurrent : Discovery 4 HSE (2012 spec)
Current : BMW Z4 20i MSport
Current : BWM Z4 3.0SI Sport Auto
Previous : Freelander 2 HSE
25th Mar 2018 6:07 pm
Redline
Member Since: 20 Jan 2018
Location: Warwickshire
Posts: 141
Many thanks to JonM - I may have solved the problem. He suggested checking the Battery Management System reset had been done on the battery change(s).
I asked the guy who changed the battery if he had reset the Battery Management System. The phone went quiet for a few seconds and then he said he'd call me back. Guess what - no phone call.
As it happens SWMBO used to be amongst others the product manager of automotive diagnostics equipment. Tonight I managed to get the loan of a pro diagnostics unit for the evening.
Lots of error codes logged - most of the systems reporting loss of comms and/or voltage problems.
Did a BMS reset and hey presto - the alternator output sits at 14.6V irrespective of load. When turned off the battery rest voltage settles at 12.7-12.8V and doesn't seem to drop like it was doing.
Cleared all the codes so lets see what happens now.
Again, thanks JonM. Current : Discovery 4 HSE (2012 spec)
Current : BMW Z4 20i MSport
Current : BWM Z4 3.0SI Sport Auto
Previous : Freelander 2 HSE
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