W219 CLS supplied with faulty aux input from factory?

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New Member
Dec 6, 2014
W219 320CDI
I've bought a 2009 CLS recently and attempted to install DAB using the aux input.
The results were literally very one sided. I blamed the DAB unit (SmartDAB) and returned it for replacement.
The second was had the same issue so, using various leads and some apps on my phone, I established the right hand channel was faulty.

I removed the command system to confirm sockets were correctly seated then took to removing the aux input.

After much research i found the correct pin outs for the back of the command and checked them against the wiring on the aux socket.
Amazingly it had been supplied with an incorrectly wired socket from the factory.

The cable is A21144063301 and when the casing is stripped off here's the pinouts:

and with a little re-jigging:

The result is pretty amazing sound quality from this SmartDAB radio.

Cannot actually believe it went into production this way! :fail


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Thanks for the update basher...i have also just got cls 2009 and would like to upgrade the radio to DAB.

Could you send me more info and links to getting this sorted?
Did you have the same sound issues using a media player through the input or was it only the DAB that was the issue ?

Been thinking of installing DAB in my CLS can I ask what DAB aerial you used?

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