T6.1 Ocean, second leisure battery monitor not found by VCDS

[scabrero]

Hi,

according to Erwin both leisure batteries control modules are connected to the J608 unit through LIN bus, but only one of them is shown in auto-scan:

Address 3D: Special Function (J608)       Labels:* None
   Part No SW: 2N0 907 427 R    HW: 2N0 907 427 H
   Component: KFG       H24 0408
   Serial number: GB24220742679
   Coding: 04002000000000200200000860B8135EB8000000
   Shop #: WSC 131071 1023 2097151
   ASAM Dataset: EV_SpeciFunctFlextVN54X 008036
   ROD: EV_SpeciFunctFlextVN54X.rod
   VCID: 3FDA42C1F7FFEC23F65-806A

   Subsystem 5 - Part No SW: 7C0 907 155     HW: 7C0 907 155
   Component: U13DCAC  H05 0870
   Serial number: A011319           

   Subsystem 6 - Part No SW: 7E0 915 181 M    HW: 7E0 915 181 M
   Component: J367-BDMConti  H03 1051
   Serial number: 77194501001909050074

No fault code found.

I wonder what the problem is. Does VCDS need to be updated to find this second module? Is the J608 unit badly coded from factory?

 

[California_Ocean]

Odd ... my T6.1 Ocean ERWIN wiring diagram identifies the battery shunts as J934 .... (Battery monitor control unit 2, on earth cable battery clamp.)

and J1116 (Battery monitor control unit 3, on earth cable battery clamp)

... and they are connected to the J608 (Special vehicle control unit) on separate LIN busses.

J367 is indeed a battery control module, but I would be very surprised if the J608 didn't throw an error if it was coded for one battery but had 2 fitted. It would be getting the total capacity totally wrong for a start.

 

[scabrero]

The Erwin schematics for my van are the same as yours. I checked the J608 coding and:

Byte 14, 0x13
Bit 4 - Battery data module 3 *is* checked (installed)

Byte 12, 0x60
Bit 5 - Battery data module 2 *is* checked (installed)

So far so good, but I don't understand why the second battery monitor module is not listed in the auto-scan. I thought the module might be aggregating both batteries internally so it appears as only one externally, but the advanced measurement function reports a capacity of just 68Ah:

IDE01839 Battery charge level 71 %
IDE01842 Usable battery charge 61 Ah
IDE08347 adapted battery capacity 68 Ah

 

[California_Ocean]

If it is the same as mine, you have 2 x 75Ah batteries - 150Ah total. If the battery charge level is 71% then that's ~ 106Ah remaining ... if the useable charge is 61Ah, then that would leave 45Ah which is 30% of 150Ah.

I would not expect the VW system to let the batteries go below 30% as this would seriously shorten their life.

So the numbers seem to stack up for 2 x 75Ah batteries.