96 C280 key programing questons...
 

The flip key for my 96 C280 sport went missing and I've ordered a new one from the dealership at $145. I was told they have to program it for an additional $50 and my questions is .can I do this myself or am I out another $50? thanks 150k on this car.

The key has two completely different security functions. The first is the remote that opens the door and turns off the alarm. The second is the drive authorization system that allows the key to start the car.

Only the first portion needs initialization. The drive authorization is already done when you get the key from MB and can not be changed. The initialization procedure is described in your owners manual and is fairly simple.

here is a guide, i have used it many times

Key synchronization Procedures

SL Models
90-95 see note 1
96 see note 3
97 see note 2
98-99 see note 4

S-Class Models
92-95 see note 1
96 see note 3
97 see note 2
98-99 see note 4

C-Class, CLK, E-Class
96 See note 3
97 See note 2
98 –99 see note 7

SLK

See note 4

M-Class

Early 98 Models up to A010609
With original AAM and keys see note 5

Later models 98-99 after A010609 see note 6

Note: All M-Class keys require the HHT for Initial Installation

Note 1: Aim transmitter at a receiver and briefly press any transmit button. Within 10 seconds, lock or unlock car at a door or trunk with the new master key.

Note 2: Aim transmitter at a receiver and briefly press the transmit button twice. Within 30 seconds, insert new key in steering lock and turn to position 2.

Note 3: Aim transmitter at inside rear view mirror receiver and briefly press transmit button twice. Within 10 seconds, insert key in the steering lock and turn to position 2.

Note 4: Aim transmitter at vehicle and briefly press the lock or unlock transmit button twice. Within 30 seconds, insert key in steering lock and turn to position 2.

Note 5: Key to position 2 (ON position), then turn off and remove key.
Hold down "lock" button, and push "unlock" button 5 times within 10 seconds. Then release buttons and push either the lock or unlock button to confirm operation

Note 6: turn key in steering lock to position 2, then to position 0 and remove. Within 10 seconds, press the lock and tailgate buttons simultaneously for 15 seconds.

Note 7: For Smart key equipped vehicles, simply insert key in the ignition switch and follow info in the cluster display

thanks carson 356 and stevebfl,
 

I've aimed the transmitter at the inside rearview, briefly pressed transmit twice and within 10 seconds inserted and turned the steering lock to position two and....key is still not locking/unlocking using the button from outside. The red and green LEDs do not light but the red LED on the radio blinks when I remove the key. The battery in the unit is tests good. Any Ideas??

Same problem with me. I cant figure out how to program this?

Just put it into the ignition and start it...
 

I lost a key to my 96 C280 Sport and when I picked up a new key the dealer said that I would need to lock/unlock the car with the key manually, then start the car using the key. The key would be programmed while in the ignition. After turning the engine off, the key then worked to lock/unlock open the trunk and windows fine.