Both key fobs only working at extremely short range

[TeddyRuxpin]

Hi,

As title, my brother currently has an issue with (my dad's) 2010 E350 with low miles and FMBSH. Suddenly, the key fob doesn't lock/unlock the car unless very close (under 2m, more like 1m). We've tried:

- Everything here: Mercedes Key Fob Not Working – MB Medic
- Both key fobs (so it must be an issue with the car)
- Changing the battery
- Holding the lock/unlock for 5 seconds until it blinks

Any ideas?

Thanks,

Ed

 

[DSM10000]

Hi,

As title, my brother currently has an issue with (my dad's) 2010 E350 with low miles and FMBSH. Suddenly, the key fob doesn't lock/unlock the car unless very close (under 2m, more like 1m). We've tried:

- Everything here: Mercedes Key Fob Not Working – MB Medic
- Both key fobs (so it must be an issue with the car)
- Changing the battery
- Holding the lock/unlock for 5 seconds until it blinks

Any ideas?

Thanks,

Ed

The internal receivers are known to either fail or reduce sensitivity.

 

[whitenemesis]

Sounds like the RF antennae or amplifier has failed and the car is only using the IR receiver..

 

[TeddyRuxpin]

Thanks folks, I found a similar response to a similar problem, via google

"Sounds like the amplifier for the remote control has failed. Your key works both over IR (receiver at the door handle) or radio (RF, receiver antenna at the rear window). RF gives better range which you are lacking now."

Looking to see where the fuse for the RF amp would be on a W212 saloon, if anyone knows that would be great so I can get him to check it tomorrow. I think it might be fuse 46 7.5A in the boot, which controls:

• FM 1, AM, CL [ZV] and KEYLESS-GO antenna amplifier
• Rear window antenna amplifier 1
• DAB band III antenna
• Alarm siren
• Interior protection and tow-away protection control unit
• Valid as of 01.06.2011 on engine 157, 276, 278: Coolant circulation pump relay

Fuse Box Diagram Mercedes-Benz E-Class (W212; 2010-2016)

Fuse box diagram (location and assignment of electrical fuses and relays) for Mercedes-Benz E-Class (E200, E220, E250, E300, E350, E400, E500, E63) (W212; 2010-2016).

fuse-box.info

(N.B. the car doesn't have keyless go)

Please let me know if you think otherwise!

Cheers

 

[TeddyRuxpin]

All rear boot fuses seem to check out just fine

 

[MrGreedy]

On the w203 dodgy key range tended to coincide with loss of good radio reception. The major channels eg Radio 1 would work, but smaller local channels were very intermittent or non existent. No fuse issue; it was debonding between the aerial on the glass and the glued on connector. I’ve not heard of that as a specific issue on the w212 (was very common on w203).

If the radio is fine and just the key, try focusing on the non-IR bits of the key receiver in the car.

 

[TeddyRuxpin]

He says the radio is fine, so I guess he needs to buy a second hand RF amp and swapping it out...

Maybe he'll leave it and I'll have to sort it once he's back...!

 

[grober]

ANTENNA, ANTENNA AMPLIFIER AND WIRINGHARNESSES MERCEDES E-KLASSE [Car] [CHASSIS] (EUROPA)

ANTENNA, ANTENNA AMPLIFIER AND WIRINGHARNESSES MERCEDES E-KLASSE [Car] [CHASSIS] (EUROPA)

mercedes.7zap.com

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