Body Control Module?

[Jpdv]

D4 (2015) started throwing some electrical dash faults (transmission, brakes etc), then wouldn't start, failing to recognise either smart key...

Mechanic came out and jump started it, reckoned it might be a failing battery. I got it home and wondered about either battery or alternator.

Local independent garage, who are not LR specific, but pretty good, have had a 3 hour investigate, and they reckon it's the body control module stuffed. What is this exactly, and does anyone know a fair price/location to get one? They're saying it needs fitting and coding to the keys. I just want to check prices etc before I go ahead - can't find much of relevance on the interweb...

[veebs]

Is the car on the original battery?

[Jpdv]

nope-second, which was my first 'assumed problem' ....you ask because?

[veebs]

Only to confirm your suspicion of a bad battery causing the issues - so often the way in these cars.

If it was able to be jump started, not sure why the garage would think the module has failed?

[Jpdv]

I hear you, but I'm somewhat in their hands... They've spent 3 hours investigating, they have a local reputation to protect, and they made a point of phoning to check whether I was content to authorise further investigation when they decided it wasn't battery or alternator. They get a regular trade in local Discoveries, but make no claim to be specific experts. I guess my options are:

1. Pay for work to date, bring home and wait for service at MR automotive in Redcliffe in 20 days (previously booked...)
2. Let them continue. Ironically, they've spoken to MR to try and source the part - but MR haven't yet looked at it themselves...

I may just wait for MR, thinking out loud. They can 'start again' with the input from the local garage, and verify whether it really is the BCM - which I'm being quoted for at around $1200 fitted, but without the work to then code/program it. Don't have to have the car to hand, but it stalls some other work I was going to do.

(Edit, and to answer your specific point about jump starting, I presume they have gone this route because I specifically asked them to check the battery and alternator, and they've found no faults there?).

[DazzaTD5]

I cant remember the last time I saw a faulty BCM, yet the main battery yes every 3 years or so.
I dont know that I would be jumping right into a BCM change, good grief so many other smaller simpler items could be at fault.

Sounds like you already have a indy Land Rover repairer that its booked with, stick to that.

[Jpdv]

Thanks guys - I think you reinforce my decision...

[LuckyLes]

I had my battery replaced yesterday after a couple of weeks of failing to start, low battery warning and numerous codes showing up on scan tool. Voltage from alternator when running good, battery voltage at 12.7 but tending to fluctuate. The battery was 3 years old.
My thoughts would be battery first.
Good luck
LuckyLes

[Jpdv]

It's a fascinating journey. The garage were 'irritated' that I didn't want them to get the vehicle transported to a specialist workshop, in addition to paying them over a grand for the BCM, and warned of doom and gloom when I told them to put it back together and that I'd sort it out in my own time. It came back to me without even having the clock reset after the battery disconnect. They've lost all future business from me. Very underwhelmed, and disappointed in what comes across as a money grubbing operation...

I've been charging it, it did over 100km today with about 5 stop/starts faultlessly. I'm inclined to think it's the battery, and will get the specialist independent (MR Automotive) to confirm or deny.

I understand that some businesses survive on a slash and burn model, but it ****es me off.

[Silenceisgolden]

It all sounds a bit sus to me. I have no idea what a Body Control Module is for, but my working life was spent designing high tech microprocessor controlled devices, and there is practically nothing that can be intermittent in electronics other than connectors. If a semi-conductor device fails, it stays failed. Likewise most electronic components. Other than a flat battery, I can see no reason why a faulty BCM would allow a jump start but not start from the cranking battery.
Have you a multimeter to check the voltage of the battery with the engine running, preferably continually while driving?

[Wojer]

It all sounds a bit sus to me. I have no idea what a Body Control Module is for, but my working life was spent designing high tech microprocessor controlled devices, and there is practically nothing that can be intermittent in electronics other than connectors. If a semi-conductor device fails, it stays failed. Likewise most electronic components. Other than a flat battery, I can see no reason why a faulty BCM would allow a jump start but not start from the cranking battery.
Have you a multi-meter to check the voltage of the battery with the engine running, preferably continually while driving?
If you have a multi meter, check battery arriving home, then first thing in the morning. I would not expect any significant drop in voltage. If there is then you have an issue.
Multi-meter handiest tool in the kit! [thumbsupbig]

[Jpdv]

I will try the multi-meter approach and report back....

[101RRS]

Just get the battery tested at a battery shop - normally free - my battery was playing up a little while back - still producing 13v, cranking amps were sort of still there but was only holding about 30Ah worth of charge not the normal 95Ah - so it would crank and start but if anything went wrong like a cold start it was not up to the job.

[Jpdv]

It's been on the CTEK charger for 24 hours, and is reading 12.76V tonight. That's around 80% charge for an AGM, I think. Interestingly, the CTEK reckoned it was fully charged and had shifted into float charge. Will see what the voltage is in the morning, and then look at a battery shop.

[101RRS]

It's been on the CTEK charger for 24 hours, and is reading 12.76V tonight. That's around 80% charge for an AGM, I think. Interestingly, the CTEK reckoned it was fully charged and had shifted into float charge. Will see what the voltage is in the morning, and then look at a battery shop.

You should test the battery when it is under a little load such as a 55w light globe - a basically dead battery might still show reasonable voltage until loaded when it then goes to nothing.

[Graeme]

The combination of only around 12.8V and the charger going to float mode suggests that the battery has a problem unless the charger is set for an SLA battery.

[Jpdv]

OK, thanks to all for the advice and comments. I got 12.9 last night when I held the multimeter properly(!). This morning, the battery read 12.89/12.9. So it seemed to hold its charge overnight, at somewhere north of 95% charge for an AGM.

However, taking 110RRS's advice, I then checked with the doors open, and all the interior lights on (mine are not LED).
It immediately dropped to 12.56, and stayed there with the doors re-closed and the lights off. That's somewhere around 75-85% charge. I'm not a battery expert, but that 'seems' to me to be quite a loss/drop from powering 3 or 4 globes for about 60 seconds? Grateful for any follow up comments...

All other things being equal, I. think I'll change the battery as a first step. Frustratingly, I don't know when this one went in, but I'm guessing it's the second on a 2015 vehicle, so this would just about fit with a 3 to 4 year life expectancy?

[RobMichelle]

3-4 years is a bonus for a battery I feel, they are a disposable item, and yes a lot of people will say they get 7-8 years which is great for them but I’m happy if I get 18 months, that’s me thou. Get the battery load tested with a proper old school load tester then buy a new one.

[josh.huber]

OK, thanks to all for the advice and comments. I got 12.9 last night when I held the multimeter properly(!). This morning, the battery read 12.89/12.9. So it seemed to hold its charge overnight, at somewhere north of 95% charge for an AGM.

However, taking 110RRS's advice, I then checked with the doors open, and all the interior lights on (mine are not LED).
It immediately dropped to 12.56, and stayed there with the doors re-closed and the lights off. That's somewhere around 75-85% charge. I'm not a battery expert, but that 'seems' to me to be quite a loss/drop from powering 3 or 4 globes for about 60 seconds? Grateful for any follow up comments...

All other things being equal, I. think I'll change the battery as a first step. Frustratingly, I don't know when this one went in, but I'm guessing it's the second on a 2015 vehicle, so this would just about fit with a 3 to 4 year life expectancy?

Opening the doors on a D4 wakes up the ECU train and can pull up to 30amps in my car. That normally pulls it down a bit.

[Jpdv]

Quick update:

1. It's all settled down after a good weekend's CTEK AGM trickle charge.
2. Lesson learned. The garage's nonsense about BCM was just that: I've run my cheap and cheerful OBD2/android software several times, and the BCM DTCs are all negative. A scanner will earn its cost the first time you need it.
3. No more warning lights. The next step is a Traxide unit, for various reasons, but that should assist in avoiding any low battery issues.
4. OBD is showing a rock steady 14.1 V system voltage when the engine is running - I'm happy.

[veebs]

Great news - thats the power of AULRO for you :)