For the the older Mercedes models such as W202, W208 and W210 it is advisable to use the IR-Adapter to read the password from the EZS. Reading the password from a working key in these models poses a threat for the working key, the EZS and the ESL. The processors in these units and keys may stop functioning due to their low capability of calculating the complexity of data that is needed to read the password. If a working key is used to read the password and the process does not complete or gets stuck in one place, this means the key or the EZS have stopped functioning. The car battery can be disconnected for 4-5 minutes and then reconnected. This will usually reset the EZS but the working key may stop functioning. If this happens, the IR-Adapter should be used to read the password.