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.
