Mercedes Benz C 43 AMG Technical Service Bulletin # S-82_70-475A Date: 090320

Mercedes Benz C 43 AMG Technical Service Bulletin # S-82_70-475A Date: 090320

Cell Phone - Calls Dropped Or Cut Off

Date: March 20, 2009

Order No.: S-B-82.70/475a

Supersedes: P-B-82.70/475 dated Nov. 14, 2005

Group: 82

Revision History

Revision Date Purpose

a 3/20/09 Applicable Models Updated

- 11/14/05 Initial issue

SUBJECT:

All Passenger Car and Light Truck Models

Telephone Calls Being Cut Off or Dropped

If you receive customer reports in the above model vehicles for telephone calls being dropped or disconnected even with adequate signal strength,

please read the below information on possible causes.

1. Dead Zones - Depending on the location and the respective network provider, 100% network coverage may not be present. Network coverage can

vary at the same location depending on the network provider. When crossing from an area with network coverage to an area without network

coverage, reception may drop to zero and the call may be cut off, even though the phone or head unit may still continue to show signal strength.

There are many things that can diminish "dead zones" and weather is a large contributor.

2. Switching Cells - While driving, the telephone transfers from network cell to the next network cell. Sometimes switching between cellular towers

can also cause calls to be dropped. This can be fixed by the customer's service provider (Verizon, Sprint, Alltel, Cingular, T-Mobile, etc.). If

customers experience dropped calls on a regular basis along the same route, they should take note of the cross streets or address and contact their

service provider and describe where the drops are taking place and time of day.

3. Cells Operating at Full Capacity - While driving, the telephone transfers from network cell to the next network cell. Each cell can only process a

maximum number of calls. If the vehicle with an active call transfers to a cell operating at full capacity, the cell cannot handle the call and it will be

dropped. The call is cut off even though the head unit and/or telephone may be showing full signal strength and anywhere from 1 to 5 bars.

These are network problems and not related to the vehicle; replacing components will NOT resolve the complaint.