This problem has been going on a while, since coming out for a door replacement in May. The sensor body got crushed in a side-swipe, so it was replaced at the body shop with a new unit. It will not light up (red/green) and it will not lock or unlock the car. Body shop did a disconnect/reconnect, same issue. I guess the sensor could be DOA, but I find that unlikely. Another possibly-related symptom is that built-in foglights work intermittently since it came out of the body shop. I'm thinking the connection point may be related, or there is a single point of failure. Any ideas?

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former: 83 300D, 97 C230, 93 400E

current: 08 C300 Luxury , 92 500SL

Have you tried the re-syncro process?

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

What's that?

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former: 83 300D, 97 C230, 93 400E

current: 08 C300 Luxury , 92 500SL

If the key locks/unlocks thru the mirror receiver & the trunk, the problem has to be in that door.

The key is synchronized to the whole system not just 1 receiver.

__________________
MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator