Mercedes-Benz bulletin LI00.20-P-078424

Complaint The remaining time shown on the instrument cluster in the workshop menu (days to next due service) is implausible (>365 days) for the following conditions: • for the date of the vehicle handover • or the last conducted and confirmed Service A/B Cause Case 1: Observe the following on vehicles with a disconnected on-board electrical system battery (12V/48V): • The period in which the on-board electrical system battery is disconnected cannot be counted by the maintenance computer. • As soon as the on-board electrical system battery is connected again, the maintenance computer automatically starts counting without making a correction to the remaining time (days until the next service). Case 2: If a disconnected on-board electrical system battery (12V/48V) can be ruled out as the cause, it is possible that: The daily turnover counter inside the electronic ignition lock (EIS) has experienced memory loss. This anomaly was detected in the EIS software from modification year 2022 onward. To do this, please check the plausibility of the daily turnover counter as follows: If "TUSZ Assyst Plus" < the actual days since "Handover Date/DAY/Month/Year," then proceed to remedy for case 2. Information: A variation of 2-3 days is still considered plausible. If "TUSZ Assyst Plus" is plausible, or if a remaining time of 365 days is permanently displayed, check whether the vehicle has been handed over. These types of cases have different causes. (The respective values are included in the maintenance data in the control unit log of the instrument cluster). Remedy For case 1: When the on-board electrical system battery is disconnected, this period must always be taken into account for these vehicles, and the following condition must be met for a correct calculation to be made: • (A): The number of days from the "date of vehicle handover or last service A/B" to the "date on which the vehicle arrived at the workshop." • (B): Remaining time (days until the next service, as shown in the instrument cluster). • (C): Days on which the on-board electrical system battery was disconnected. The formula requires the following condition to be complied with. 365 - (A) [days] = (B) - (C) [days] For case 2: If the on-board electrical system battery (12 V/48 V) was not disconnected and the remaining time shown in the customer or workshop menu on the instrument cluster (days until the next

Owners of the 38 model years this bulletin names have filed 575 complaints with NHTSA since 2015. 193 of them name Electrical System — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.