Heated seats error after repair, although it works correctly

[sm4rk]

As discussed in the OT of another thread together with the very kind dv52 (Australia)
I open this new thread due to an error in the central electrics module 09 that I haven't been able to eliminate for years.


in 2021, following the failure of the heated seat element, it was replaced.

From that moment it has always worked correctly, but OBD11 has always detected a permanent error that cannot be eliminated.

this is the very first error scanned at the time (year 2021):
Codici guasto:

B133914 - Autorizzazione riscaldamento sedili Interruz./c.c. a massa

statico

Date: 2021-09-22 11:54:45

Mileage: 169844 km

Priorità: 6

Contatore frequenza guasti: 1

Contatore di apprendimento: 26

Stato morsetto 15: ON

Stato morsetto 50: OFF

Tensione: 12.4 V

Temperatura esterna: 25.0 °C

Status Bremslichtschalter (HW): OFF

Status Bremslichtschalter (CAN): OFF

OFF: non azionato

Luci di posizione: non azionato

Gestione automatizzata delle luci: non azionato

Anabbaglianti: Azionato

Luci di parcheggio sin.: non azionato

Luci di parcheggio des.: non azionato

Letzte Weckursache/ Werte [00;2E]: keine Störschutzursache

CAN-Bus_aktiv: ON

also reported in the latest scans 2024:
Difetto

   Unità  di controllo: 09 Central Electrics

   Difetti attivi: 1

   Difetti inattivi: 0

   Descrizione sistema: BCM MQBAB H

   Numero software: 5Q0937084AE

   Versione software: 0124

   Numero Hardware: 5Q0937084AE

   Versione Hardware: H16

   Numero seriale: 00011410000025

   Nome ODX: EV_BCMCONTI

   Versione ODX: 012001

   Guasti:

       B133914 - Seat heater enabling Open circuit/short circuit to ground

           static

               Date: 2024-06-10 14:10:13

               Mileage: 194702 km

               Priority: 6

               Malfunction frequency counter: 1

               Unlearning counter: 23

               Terminal 15 status: On

               Terminal 50 status: Off

               Voltage: 12.2 V

               Outside air temperature: 29.5 °C

               Status Bremslichtschalter (HW): Off

               Status Bremslichtschalter (CAN): Off

               Off: operated

               Parking light: not activated

               Automatic high beam assist: not activated

               Low beam: not activated

               Parking light left: not activated

               Parking light right: not activated

               Letzte Weckursache/ Werte [00;2E]: keine Störschutzursache

               CAN-Bus_aktiv: On





   Chilometraggio: 194706 km

   Data: 2024-06-10 14:19
Despite this error since the replacement, the resistance has always worked correctly.

Therefore it is not a big problem if this error there is no way to eliminate it.

It would just be nice to have the full scan without errors, or maybe only see future errors that actually need to be repaired without seeing this error which does not imply malfunctions

Do you think there is any way to eliminate that error since the resistance works correctly?


Talking to a guy on an Italian forum, he told me that I probably had the old model resistor coded in the control unit, while the one mounted was the new version which changed slightly from the previous one...

He also provided me with photos of some wiring diagrams to show me the difference, but the diagrams provided I don't believe are for my 2014 MK7 car, so I don't think they should be included here.


I don't know if this difference in resistance really exists




Is there anything we can do to fix this error?

[dv52 (Australia)]

Marco: The seat heating error is classified as "static" - which means that it's been confirmed by the fault monitoring system in the module. Both of your SCANs say Fault frequency=1 - which means that the fault has NOT been re-registered in fault memory in a subsequent drive cycle since the date/time stamp for the error. This is odd, but maybe you tried clearing the error shortly before making the SCAN!

Yes, I tend to agree with your Italian forum colleague! If the seat heating function works OK on this car after being replaced and given that the central electrics module error won't clear.

Yes also, there were differences in the resistor set-up for seat-heaters on the mk7.5 and mk7 (see below)

I'm really not sure how to diagnose this problem because clearly the seat-heater is working. My only suggestion if you want to pursue this matter is to talk to the workshop that repaired the seat heater in 2021 and confirm the part number of the new seat heater!

Don

[sm4rk]

contacting the workshop that changed the resistor I think does not leads to the information we want to know, as it was a generic mechanical workshop that purchased the resistor from a spare parts dealer in 2021.

I believe that finding the code today, in 2024, I think is truly difficult, if not impossible.

Somewhere I should have the photo with the code of the old resistor removed before being thrown away (but I have to find it again).

At this point, however, I think I have understood that since it is a different resistance from the previous one, I will have to keep the mistake for life.

Luckily it's nothing important...
it was just a whim to see the system completely clean


----edit----


I found a note in the notes of the phone, where I wrote down the code of the resistor (5G0 963 555 AF) which I believe is the code of the original disassembled and thrown away one, as I remember never having seen the new one...
I had gone to get the car when it had already been mounted...


To get the code for the new one, I don't know if it is possible to find it easily by dismantling some parts of the seat

[dv52 (Australia)]

Marco: Just to be clear - the second heater element on a Golf mk7.5 in the wiring diagram in my previous post is for the seat back-rest. The earlier model Golf mk7 didn't have a back-rest heater! 

Because there are 2 x heater elements on a mk7.5, the resistance of the individual elements will be different because the combined circuit load needs to be roughly the same for the central electrics modules in both models. So, if a seat-base heater element for a mk7.5 was used on a mk7, it will likely produce an error - I think!

This is how the seat base is constructed on a Golf mk7:

The seat heater is bonded onto the seat padding - labelled 2 in my picture above. When replacing the seat heater, the new heater element has a number of bonding pads which are removed before fitment and then the heater is "stuck-to" the seat padding. So, even if you get access to seat padding (2 in my picture), you might not be able to see the part number because there is a 50% chance that it's on the side of the element that's bonded to the padding!!

My advice - don't bother: it's just an error-message and the heater works OK!

Don

[sm4rk]

Certain! Certain!

I also said it wasn't a big deal.

It was just to have a clean scan without errors, but it doesn't matter if it can't be deleted, the important thing is that the resistance works correctly... and it does.

so no problem.

Just to talk, I would just like to ask to understand... if by chance I had had the code for the new resistor, would we have been able to eliminate the error or would it not have changed the resolution?

Because think about it, on the driver's side I now have the mk7.5 resistor, while on the passenger side I have the original mk7 resistor