P1B0200 - Battery monitoring control module Faulty

[MrObrazZz]

Hi everyone,

Maybe someone had this fault? Start stop system stop working, but car seems okay to drive.
Is it problem with Battery monitoring control module? Or something else?
Couldn't find any information about this fault.

Thank you for your help.

Fault

Control unit: 19 Gateway

Active faults: 0

Inactive faults: 1

System description: GW MQB High

Software number: 5Q0907530M

Software version: 1144

Hardware number: 5Q0907530F

Hardware version: 125

Serial number: 0000984848

ODX name: EV_GatewLear

ODX version: 009013

Faults:

P1B0200 - Battery monitoring control module Faulty

static

Date: 2021-10-03 17:13:29

Mileage: 208636 km

Priority: 1

Malfunction frequency counter: 1

Unlearning counter: 180

Supply voltage, terminal 30: 11.8 V

Terminal 15: On





Mileage: 208636 km

Date: 2021-10-03 17:16

 

[Walone]

Could be the battery itself, is it very old or have you had a new battery fitted and not coded to car?
If it's not the original battery is it the correct type?

 

[MrObrazZz]

Could be the battery itself, is it very old or have you had a new battery fitted and not coded to car?
If it's not the original battery is it the correct type?

Hi,
Battery has been changed but the fault remained adaptation has done as well

 

[RUM4MO]

Basically as the self diagnostic system is pointing to the battery dongle, possibly it is it.

I have been, for some time, been monitoring the charging voltage via the "ciggy lighter" socket using a cheap plug in DVM (£5 from ebay), and usually the "on power" voltage is round about 12.5V and the "over run" voltage is 13.6V for as long as the battery needs recharging. Okay maybe sad to be someone that takes an unhealthy interest in that, but, after maybe 9 months of seeing things as being expected, now things have changed and while the initial "on power" charging voltage is 12.5ishV, at all or most times "on power" and "over run" the charging voltage has changed to being 14.7>14.9V - which is concerning me!

So far I have checked the car for logged faults using VCDS and there are no faults being logged, I have also checked the battery using my CTEK battery tester and it gives out "battery good" results, in as much as present voltage being 12.7V - which is probably higher than the normal "80%" charged condition that the smart charging system is aiming for, and the battery CCA is still close to its original value and slightly higher than when I last checked it at its service in August this year.

Time to start checking everything that I can in the BMS using VCDS!

Edit:- obviously the auto Stop/Start is working as expected when I allow to!

 

[adam davies]

Basically as the self diagnostic system is pointing to the battery dongle, possibly it is it.

I have been, for some time, been monitoring the charging voltage via the "ciggy lighter" socket using a cheap plug in DVM (£5 from ebay), and usually the "on power" voltage is round about 12.5V and the "over run" voltage is 13.6V for as long as the battery needs recharging. Okay maybe sad to be someone that takes an unhealthy interest in that, but, after maybe 9 months of seeing things as being expected, now things have changed and while the initial "on power" charging voltage is 12.5ishV, at all or most times "on power" and "over run" the charging voltage has changed to being 14.7>14.9V - which is concerning me!

So far I have checked the car for logged faults using VCDS and there are no faults being logged, I have also checked the battery using my CTEK battery tester and it gives out "battery good" results, in as much as present voltage being 12.7V - which is probably higher than the normal "80%" charged condition that the smart charging system is aiming for, and the battery CCA is still close to its original value and slightly higher than when I last checked it at its service in August this year.

Time to start checking everything that I can in the BMS using VCDS!

Edit:- obviously the auto Stop/Start is working as expected when I allow to!

Possibly your cheap ebay item is faulty !!! not the car

 

[RUM4MO]

Possibly your cheap ebay item is faulty !!! not the car

That would be very convenient if it was, to cover that possibility, I have laid out my "ciggy socket" test lead and a trusted DMM, but having found the battery in a better state than expected charge wise after its last use, I think that sadly I'll be disappointed tomorrow - though I hope not!

 

[RUM4MO]

Well I have confirmed that my cheap "ciggy lighter" socket DVM is okay, so that means that there really is something wrong with the battery charging system, if I remove the battery dongle lead, the voltage drops to 14.1-14.5 from 14.7-14.9!
No declared issues with alternator or anything else, battery "useful charge" is listed as being 36Ah that battery started life as being 59Ah, but auto Stop is enabled within a mile or so from a cold start. Battery charge level is logged as being 75-78% so that can be the reason why the charging is still enabled, but not at that constant level I'd think. I ran the car with the battery dongle unplugged and checked the charging system and battery stats, I'm guessing that under these conditions it is normal to see the battery level as being indicated as 100% and maybe even under that condition, the charging voltage level is allowed to sit at a safeish default level of 14V. I even tried changing the battery serial number to see if doing that prompted the charging system to sort itself out, but so far it has not done. Maybe it is a situation that the battery dongle is "out of spec" but not far enough out to prompt logging a fault code for that device.

Edit:- the control wire is still fully plugged into the alternator and the CAN Gateway plugs are all still fully engaged.