Mercedes A150 UHI (telephone connector help)

[Markhicks]

Hi all

I have a Mercedes A150 2007 Reg

I have just purchase a Mercedes Bluetooth adaptor and plugged it into the uhi cradle by the hand brake and I’m not getting any power / no light coming onto the Bluetooth adaptor, I have check the Bluetooth adaptor on another car and it’s working great I checked all fuses under the Matt on the drivers side and all looks good so really stuck on what todo next, I was looking for the main control box for the uhi but can’t find it anywhere ( checked under all seats boot) I have also rang Mercedes to check if my car is ok to except the Bluetooth adaptor and they told me my car has all the bits for a telephone / Bluetooth adaptor, was thinking it could be a fault on the uhi adaptor but Mercedes has said this is very rare

has anyone got a electrical layout of the telephone system for this car or can help me locate the telephone control box

many thanks
Mark

 

[ZZZZ]

...could be a fault on the uhi adaptor but Mercedes has said this is very rare ...

If by rare they mean "one of the most common faults know for W169" then yes, they're absolutely correct!

Hi Mark, and welcome to M-BO

The UHI unit is under the passenger seat (in a RHD car).
It gets water damage very often, as one of the other common issues with W169 is blocked central water drain, under the cabin filter - lets water into A/C system, and eventually to the battery compartment, SAM and UHI.

I check the water drain every couple of weeks in my A200 (06-reg).

Also, check the bottom of battery compartment, and major ground points - front door frames, about couple of inches off the floor, right behind the rubber protector trim.

Here're the relevant WIS files, hopefully useful.

If the UHI is water damaged / corroded, let me know - I've upgraded my head unit, so all the old components of the MOST (fibre-optic network) became redundant - removed the CDC, but never bothered with UHI - it was working perfectly well before the upgrade: this car never had the water ingress problem ...

Cheers,
David

 

[Markhicks]

If by rare they mean "one of the most common faults know for W169" then yes, they're absolutely correct!

Hi Mark, and welcome to M-BO

The UHI unit is under the passenger seat (in a RHD car).
It gets water damage very often, as one of the other common issues with W169 is blocked central water drain, under the cabin filter - lets water into A/C system, and eventually to the battery compartment, SAM and UHI.

I check the water drain every couple of weeks in my A200 (06-reg).

Also, check the bottom of battery compartment, and major ground points - front door frames, about couple of inches off the floor, right behind the rubber protector trim.

Here're the relevant WIS files, hopefully useful.

If the UHI is water damaged / corroded, let me know - I've upgraded my head unit, so all the old components of the MOST (fibre-optic network) became redundant - removed the CDC, but never bothered with UHI - it was working perfectly well before the upgrade: this car never had the water ingress problem ...

Cheers,
David

Hi David

Thanks you for the info, I will get on it ASAP and

If by rare they mean "one of the most common faults know for W169" then yes, they're absolutely correct!

Hi Mark, and welcome to M-BO

The UHI unit is under the passenger seat (in a RHD car).
It gets water damage very often, as one of the other common issues with W169 is blocked central water drain, under the cabin filter - lets water into A/C system, and eventually to the battery compartment, SAM and UHI.

I check the water drain every couple of weeks in my A200 (06-reg).

Also, check the bottom of battery compartment, and major ground points - front door frames, about couple of inches off the floor, right behind the rubber protector trim.

Here're the relevant WIS files, hopefully useful.

If the UHI is water damaged / corroded, let me know - I've upgraded my head unit, so all the old components of the MOST (fibre-optic network) became redundant - removed the CDC, but never bothered with UHI - it was working perfectly well before the upgrade: this car never had the water ingress problem ...

Cheers,
David

 

[Markhicks]

Hi David

after taking the seat out I found the box it looks a little corroded was going to try and maybe replace it with a ebay special

 

[ZZZZ]

Yeah, I'd say definitely replace
These are not too expensive on eBay - if I remember correctly, around £20.
You can always open yours to see if it's salvageable, but replacement with an undamaged unit is your best option.

 

[Markhicks]

Yep def going for the replacement - see photos

 

[ZZZZ]

Yup, that's it - at least this one didn't drain your battery overnight - known to happen quite often.
Let me know if you can't get any joy with eBay - I'll dig mine out, before I sell the car: it's only there for its weight ha-ha - the Android head unit does everything.

 

[Markhicks]

Hi David

well replaced the unit under the seat with one from eBay and fitted and still not working, was thinking I could try one last thing and replace the uhi connecter or give up and upgrade the stereo with a built in Tel Bluetooth

 

[Alfie]

You need to clean up the plug aswell as it will have also had water ingress. Check the fuses too as the phone controller will almost certainly have blown one. It is extremely unlikely the uhi connector has failed.

 

[Markhicks]

Hi all

I have check connection and they look all good and fuse is fine but still I’m not getting any lights / activity on the Bluetooth adaptor ( I know the adaptor works) I’m getting power to the cradle as well ,HELP

 

[Alfie]

Is the Bluetooth adapter fully inserted onto the uhi port?
Have you tried it with the ignition on?
What happens when you depress the back of the HFP adapter for a few seconds? Does the blue light flash?

 

[Markhicks]

Hi Alfie

yes def in correctly and tried with ignition on, when I hold the adaptor still nothing happens with no light flashing, I have double checked the adaptor on another car and as soon as I plug it in and turn the ignition on the blue light flashes so I know that works
Cheers
Mark