Mercedes Benz Truck GL 450 (164.871) V8-4.6L (273.923) Technical Service Bulletin # LI82-85_P-048914 Date: 100218
COMAND(R) - 'Drive Unavailable, Temp. Too High' Message
COMAND APS: Fault message "Drive unavailable, temperature too low or too high"
Topic number LI82.85-P-048914
Version 1
Design group 82.85 Navigation and communication systems (CNS, ICS, COMAND, FleetBoard)
Date 02-18-2010
Validity Model 171, 230, 164, 251, 169, 245, 211, 219, 203.7 with COMAND (code 512 or 527) and code 809 or 800 (NTG2.5)
Model 463 with SA code EU1
Reason for change
Reason for block
Complaint:
Complaint 1:
At high altitudes (over approx. 3000 meters above sea-level) the navigation main menu sporadically displays the fault message "Drive unavailable,
temperature too high".
The following functions are restricted due to the shutdown of the hard drive.
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- Navigation
- Voice control
- Address book
- Music register (downloaded music onto the head unit hard-drive)
- Gracenote database for identifying album, track and performer information on an audio CD
Complaint 2:
The navigation main menu permanently displays the fault message "Drive unavailable, temperature too low or too
high"
Cause:
Re 1.)
The hard drive shuts down at high altitudes (over approx. 3000 m) and when the temperature of the hard drive is high.
a) At low altitudes the message disappears and the COMAND unit (A40/3) operates without problems. This is due to a safety feature created to
protect the hard-drive from permanent damage.
b) High hard drive temperatures are increased by high volume settings especially in vehicles without sound system (SA code 810), high outside
and engine temperatures and unfavorable settings on the heating/air conditioning. With the altitude increase and decreasing of air around
hard-drive assembly, the HDD starts the shut down process as the surrounding head unit temperature also reaches around 55 degrees Celsius.
The head unit is working as specified in this use case.
Re. 2.)
There is a hardware fault in the COMAND unit (A40/3).
Remedy:
Remedy 1.)
To prevent damage to the hard drive, it is shut down at high altitudes and high temperatures. This is due to a safety feature (series production
configuration). => Do not replace any equipment!
Remedy 2.)
If the fault occurs constantly, replace the COMAND APS (A40/3). Refer to EPC.
Note:
If the vehicle is fitted with a COMAND APS (A40/3) with PIN theft protection, the PIN code must be recorded in the VeDoc system. Pay attention
to the relevant information during initial startup with DAS / Xentry Diagnostics.
Symptoms
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