Mercedes Benz C 43 AMG Technical Service Bulletin # P-80_57-20 Date: 030225

Mercedes Benz C 43 AMG Technical Service Bulletin # P-80_57-20 Date: 030225

Audio System - RF Interference Explanation

Date: February 25, 2003

Order No.: P-B-80.57/20

Supersedes:

Group: 80.57

SUBJECT:

Models 129, 140, 170, 202, 203, 208, 209, 210, 211, 215, 220 and 230

155

Radio Interference for RF Keys

A number of different RF operated Systems are active such as cordless headphones, garage door openers, remote reading thermometers, etc. when

active, operate within the frequency range of the remote control key as well as the keyless go cards and keys. These transmitters operate with several

times the power output of the key or card whose frequency and power output is limited by size.

If one of the above mentioned RF operated Systems is located near the vehicle and is active, strong interference could be present which occasionally

could prevent the vehicle from being locked/unlocked or starting the engine.

In such circumstances, model 170 vehicles which are only equipped with an RF remote key can be locked/unlocked using the mechanical key. All

other vehicles have an IR system in parallel to the RF system so the vehicle can be locked/unlocked from a short distance at any time.

This is not an indication of a defect, merely the limitations of operation in the presence of other stronger radio frequency emitters. If the customer

experiences this circumstance, please explain the cause.

Please also observe the corresponding notes in the 215, 220 and 230 Owner's Manual for keyless go cards recommending that the driver carry the

vehicle key as well, as that would help avoid any difficulties arising from this circumstance.