Member Since: 14 Sep 2011
Location: annecy
Posts: 233
B11DB-87 (2A) Battery monitoring module - Bus signal/message
This is the only B message I get when the car goes haywire and lights ALL the warning lights in sequence so I suspect it might have something to do with the problem.
How do I test this thing? It just seems to be a lump of metal attached to the positive terminal with another short wire attached. I am told it has a fuse somewhere in it but where? Any guidance gratefully received!
thanks
4th Feb 2022 2:07 pm
sceh
Member Since: 14 Sep 2011
Location: annecy
Posts: 233
So this is it on the negative terminal?
whereas this on the positive is called the fused harness?
How do I test these?
4th Feb 2022 2:41 pm
tzdisco4
Member Since: 12 Jan 2016
Location: Lower Saxony
Posts: 10
Well, I'm wondering a bit whether you should proceed with your testing because you are asking what is the plus and what is the minus terminal. But anyway. In the second picture with the fuse harness, it looks to me like the connector of the harness is not properly attached to the positive terminal of the battery. The connector is not pushed far enough to the battery terminal. If this is true, the conection resistance would cause a too high voltage drop during cranking what could cause all the errors.
In addition, corrosion appears to be present. Unfortunately, the resolution of the image is not high enough to see all this accurately.
Before disconnecting, wait 2 minutes after turning off the ignition so that the ECUs are properly shut down.
Thomas
7th Feb 2022 3:11 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4657
Slightly better resolution.
sceh wrote:
So this is it on the negative terminal?
Click image to enlarge
whereas this on the positive is called the fused harness?
Click image to enlarge
yµ (idµ - eAµ) ψ=mψ
7th Feb 2022 3:24 pm
tzdisco4
Member Since: 12 Jan 2016
Location: Lower Saxony
Posts: 10
Yes, the connector on the positive terminal is not connected properly. It sits much too high. The positive terminal of the battery must extend minimally out of the connector at the top. Only then can you generate enough clamping force to keep the contact resistance to a minimum. It also looks like some corrosion (the white spots).
Thomas
7th Feb 2022 3:42 pm
sceh
Member Since: 14 Sep 2011
Location: annecy
Posts: 233
Many thanks. I reseated it and pushed it further doan and clamped it tight. I have not started the car since the tests I did earlier because I am waiting for the voltage to settle. I will let you know
10th Feb 2022 12:04 pm
sceh
Member Since: 14 Sep 2011
Location: annecy
Posts: 233
IF this turns out to be the problem I will buy you a bottle of champagne. I thought I had seated it properly but with the judicious use of a hammer I managed to push it much further down and the bolt felt better to tighten. The voltage on the battery reads 15.1 running according to IID nd the fuel gauge has a higher reading too!
I will update this tomorrow. Thanks so far
10th Feb 2022 3:52 pm
robpenrose
Member Since: 12 Jan 2016
Location: Surrey / SW London
Posts: 2136
Is that an AGM battery? Its best to use an AGM on a D4. But if you have changed to something else, you need to update the BMS with the correct battery type.
Current: D4 HSE
Previous: BMW Z4M Coupe
Previous: Land Rover Defender 90 CSW Td5
Previous: Land Rover Discovery Td5 ES
10th Feb 2022 4:06 pm
sceh
Member Since: 14 Sep 2011
Location: annecy
Posts: 233
No a Vrat 95aH. I updated the BMS though
10th Feb 2022 4:26 pm
sceh
Member Since: 14 Sep 2011
Location: annecy
Posts: 233
I reseates and tightened the battery positive terminal and things seems to have improved BUT to day I took it out and after 200 metres had the HDC/ system fault, DSC and EBA of course - all things which depend on the ABS system. On the bright side, I did not have a millon other tlights as before and have a couple of faults:
ABS-Brake Module
U0126-00 (AB) Lost communication with steering angle sensor module
( on 13-02-2022 09:00:33 at 61752 km )
RLM-Suspension
U0416-68 (A7) Invalid data received from vehicle dynamics control module - Algorithm based failure - event information
( on 13-02-2022 09:00:40 at 61752 km )
and then later
ATCM-Terrain Response
U0415-68 (2C) Invalid data received from ABS control module - Algorithm based failure - event information
( on 13-02-2022 09:07:50 at 61752 km )
I checked wheel speeds and ABS valves using IID and all seems OK. I have not yet managed to repeat this after clearing the faults.
ANy ideas? Does not seem to be the battery
13th Feb 2022 10:04 am
sceh
Member Since: 14 Sep 2011
Location: annecy
Posts: 233
Getting worse. Now I can start it and immediately all the warning lights fire up and when I connect IID I can't read any live values. I despair..
14th Feb 2022 11:59 am
sceh
Member Since: 14 Sep 2011
Location: annecy
Posts: 233
I checked the voltage across the battery yesterday and it was 12.6. Today it is 12.45 but since it starts fine I would have though this was OK since when it is running and I measure it is 14.8v
The voltage from negative to positive is 12.45 and from positive to chassis and positive' to engine it is the same. For positive to engine I use the positive terminal and the aircon pipe close by. The only thing I notice is the the measured voltage here drops quite consistently. Problem?
14th Feb 2022 12:05 pm
Disco_Mikey
Member Since: 29 May 2007
Location: Dundee, Scotland
Posts: 20731
sceh wrote:
ABS-Brake Module
U0126-00 (AB) Lost communication with steering angle sensor module
( on 13-02-2022 09:00:33 at 61752 km )
Member Since: 14 Sep 2011
Location: annecy
Posts: 233
Yes, perfect. In fact , IID tells me all of the errors are not errors so there are no faults with the EPB or the ABS for example. This seems to be a comms problem either caused by a faulty connection somewhere or the battery voltage being unstable
14th Feb 2022 1:27 pm
tzdisco4
Member Since: 12 Jan 2016
Location: Lower Saxony
Posts: 10
sceh wrote:
ABS-Brake Module
U0126-00 (AB) Lost communication with steering angle sensor module
( on 13-02-2022 09:00:33 at 61752 km )
For this error the workshop manual states this procedure:
Refer to the electrical circuit diagrams and check the power
and ground connections to the module. Using the
manufacturer approved diagnostic system, complete a CAN
network integrity test. Refer to the electrical circuit
diagrams and check the CAN network between the steering
angle sensor module and traction control module.
To me it sounds like that the communication between this sensor and the ECU is some what degraded. I'd check the ECU's plug first, as your IIDTool reported the angle values with out any problems.
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