2020 Mercedes Benz Truck ML 350 Technical Service Bulletin # LI82-62_P-041478 Date: 120921

2020 Mercedes Benz Truck ML 350 Technical Service Bulletin # LI82-62_P-041478 Date: 120921

Audio System - Various Sound Amplifier Concerns

Sound amplifier: No sound after engine start, sound amplifier not in quick test, interference noise

Topic number LI82.62-P-041478

Version 1

Design group 82.62 Loudspeakers, amplifiers, antennas

Date 09-21-2012

Validity Model series 164, 251 with code 810 and code 805, 806, 807 or 808 (NTG2)

Reason for change

Complaint:

^ No sound after engine start

^ Sound amplifier (A2/13) not in quick test

^ Interference noise from speakers

Cause:

1. Water ingress in sound amplifier (A2/13)

^ due to unplugged condensation drain hoses

^ incorrectly cemented windshield

^ leaking seal between crossmember under windshield and interior compartment

2020 Mercedes Benz Truck ML 350 4MATIC (164.186) V6-3.5L (272.967) Page 23

2. The software in the flash memory was overwritten

Remedy:

Remedy 1. Check sound amplifier (A2/13) for traces of water. Check condensation drain hoses for correct seating. Perform rain test and check

interior compartment for leaks. Eliminate leaks and replace defective sound amplifier (A2/13) in accordance with parts note.

Remedy 2. In some cases the sound amplifier (A2/13) can be made to respond via XENTRY again by means of a voltage reset. In this case, upload

the latest available software with XENTRY and wait for the bus to become idle. If the sound amplifier (A2/13) does not respond to XENTRY and if

it still does not appear in the quick test, the sound amplifier (A2/13) must be replaced. After replacing the sound amplifier (A2/13), it must be

flashed to software release 43/06 or higher.