2003 Mercedes S-Class Owner's Manual - Page 328

Practical hints Unlocking/locking in an emergency Changing batteries If the batteries in the SmartKey or the KEYLESS-GO* card 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! 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. SmartKey i When changing batteries, always replace both batteries. The required replacement batteries are available at any authorized Mercedes-Benz Center. 1 Mechanical key 2 Battery compartment Replacement batteries: Lithium, type CR 2025 or equivalent. Remove mechanical key 1. Insert the mechanical key in side opening and push gray slide. The battery compartment is unlatched. Pull the battery compartment out of the SmartKey housing in direction of arrow. Remove the batteries. G Keep the batteries out of reach of children. If a battery is swallowed, seek medical help immediately. 328