# F26 X4 35d: SOS Call System Malfunction - Where is the TCB module located to replace battery?



## daMANiack (Nov 22, 2006)

Hi,

I get the *SOS Call System Malfunction error message* and had the X4 serviced last week and BMW service advised that the fault is caused because the TCB battery has failed and needs to be replaced.











I've looked everywhere in the trunk and I can't locate.

Does anyone know where this TCB module is located?

Cheerz


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## BimmurBrothor (Jun 30, 2017)

Your in the right area...
The panel has to be removed...driver side rear panel...here's my X3...once panel is removed look to the bottom/down.









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## daMANiack (Nov 22, 2006)

Hi,

Thanks for replying and picture.

Standing at the back of my X4, under the left rear trunk panel is an large amplifier with an aluminum case, I suppose acting as a heat-sink.

Below the amplifier is a plastic recess or bin that contains the screwdriver and hazard reflective sign. There looks like something below the plastic recess that has metal and plastic on it, but I'd have to remove to recess to verify.

Cheerz


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## BimmurBrothor (Jun 30, 2017)

daMANiack said:


> Hi,
> 
> Thanks for replying and picture.
> 
> ...


I think you may have uncovered it.

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## daMANiack (Nov 22, 2006)

Hi,

No luck, there is the amplifier and a module under the bracket but the 2 connectors come out the bottom rather from the end of the module and no optical fiber wire or connector.




























I'm at a lost, looks like I'll have to pay an additional A$140 over the cost I can buy the TCB battery for BMW Service to fit a battery. 

Thanks for trying to help.

Cheerz   




BimmurBrothor said:


> Your in the right area...
> The panel has to be removed...driver side rear panel...here's my X3...once panel is removed look to the bottom/down.
> 
> 
> ...





BimmurBrothor said:


> I think you may have uncovered it.


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## daMANiack (Nov 22, 2006)

Hi,

I spoke to BMW service again and the service tech guy said they'd under quoted the labour cost, I should've been quoted for 3 hours work and not A$40.

Anyway, he checked my vehicle and said because it was JUST OUT OF WARRANTY, he'd put in a warranty repair request and it was accepted so I won't have to pay a cent. 

As my 2016 X4 35d had upgraded electrics, the TCB module is under the roof lining, I assume near the rear roof shark fin.

It was a great outcome for me.

Cheerz


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## BimmurBrothor (Jun 30, 2017)

Interesting 

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