2004 Mercedes C-Class Owner's Manual - Page 307

Practical hints Unlocking/locking in an emergency Changing batteries in the SmartKey If the batteries in the SmartKey are discharged, the vehicle can no longer be locked or unlocked. It is recommended to have the batteries replaced at an authorized Mercedes-Benz Center. Warning! Insert mechanical key 1 in side opening and push grey slide. Battery compartment 2 is unlatched. Pull battery compartment 2 out of the SmartKey housing in direction of arrow. G 1 Mechanical key 2 Battery compartment Replacement batteries: Lithium, type CR 2025 or equivalent. Keep the batteries out of reach of children. If a battery is swallowed, seek medical help immediately. Batteries contain materials that can harm the environment if disposed of improperly. Recycling of batteries is the preferred method of disposal. Many states require sellers of batteries to accept old batteries for recycling. i When changing batteries, always replace both batteries. The required replacement batteries are available at any Mercedes-Benz Center. Remove mechanical key 1 ( page 305). 3 Battery 4 Contact spring Remove the batteries. Using a lint-free cloth, insert new batteries under contact spring with the plus (+) side facing up. Return battery compartment 2 into housing until it locks into place. 307