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As more and more reports are coming in that their COMAND units are malfunctioning when dealing with the GPS Date beacon that is sent out from the satellites for GPS devices to synchronize the date/time, many COMANDs are starting to show a bug in the software code where the COMAND is not correctly dealing with the rollover of the GPS protocol.

For those interested in the technical aspects, it is crucial to the operation of the GPS system to maintain an extremely accurate Date and Time system, as your location is calculated using triangulation from multiple satellites, and the delays in which the signal arrives to your receiver allows your COMAND to calculate your position in relation to the satellites. To do this, it must have a very accurate clock, and locked on to at least 3 or 4 satellites to determine your location. A part of the GPS protocol is a beacon that is delivered over the GPS signal with the payload being a date/time value. As in most anything computer related, it comes down to multiples of 1024. Just so happens, the date is derived from a value of the current week on a 1 to 1024 number. 1024 weeks is 7268 days, and after this time has elapsed, the week number cannot roll over to a Week 1025 value, so it simply reverts back 1 one as it was designed to do. It is now being revealed that the software running the on many models of the COMAND units is not mitigating this change correctly and the code was incorrect or not-existent to adjust accordingly.

This is resulting in many COMAND models to display an incorrect date. So far, I have either seen for myself, or heard of the following COMAND units experiencing this malfunction. I welcome input from other members to add to this list, and if they were able to discover a mitigation for it. A "*" indicates I have personally witnessed this.

W210/W208 - COMAND 2.0 (and all other Mercedes-Benz vehicles this was installed in, including the G-Wagen in the mid 2000s)*
- Reverts date back to 1999.
W215/W220 - COMAND 2.5
- Changes date to late 20xx.
W211/W219 COMAND NTG 1.0 DVD-based Navigation.
-Changes date to incorrect value.
W216/W221 NTG 3.0 with current Telematics update.
-I have witnessed on my S600 the date is showing December 28 2018, so a change in the week, but correct year. Others I have seen revert to April 2006 and will not save changes.*
W211/W219 2009 MY (Final production models) NTG 2.5
-Reports are running current firmware and still have error.

Please note - this only affects your COMAND if you have Navigation as well. For W211/W219 that have a COMAND without the Navigation processor and drive in trunk will not be affected by this.f I am still evaluating the impact this potentially causes, other than possibly providing an incorrect ETA and an annoyance.

2009 seems to be the cutoff date - the NTG 2.5 in the W211/W219 and 2009 was the final year for pre-facelifted W221 S-class and CL-class with the NTG 3.0. With the news that the NTG 3.0 and 3.5 will no longer receive Map Updates, which MBUSA and the headunit manufacturers have a potential to profit from, have abandoned an update beyond the 2015 update, so these are currently in the "obsolete" category it appears according to MBUSA. This leads me to believe that nothing will be done to address this, and I am highly confident that a firmware update on all models would remediate this, so some new code and it would be fixed, but I honestly do not expect a fix for it, but will be delighted if they do, and hope they do.

Other units may be affected, so feel free to comment with your experiences with this and if you were able to mitigate the problem.

We know it affects the date of the COMAND, but I am interested in the hidden impacts it may be having, such as corrupting the ASSYST+ data on oil changes, replenishment, etc., and am currently investigating this very thing and will report back my findings.

The mitigations I have found to work comes at the price of working Navigation. You can potentially remove the Map CD-ROM in the COMAND 2.0/2.5 and it will not have access to additional data it feels it needs to force GPS time, so it falls back to manual mode and does not adjust it to GPS. This occurred after a September 2001 firmware update was installed (Version US 7.23) and did not insert a Map disc. The date stayed at what I set it at, although the system did have the ability to receive GPS signals, it did not use them until the Map disc was introduced. I will do additional experimenting with this.

On the W216/W221, disabling the Navigation functionality using DAS on the COMAND will successfully disable this portion of the COMAND, and time sync with GPS will be disabled. This is not a practical workaround admittingly, as not everyone has their own Xentry Kit and can perform these operations, and you sacrifice a fully functioning Navigation system.

Some may, however have moved on to their iPhone for all of their GPS and Navigation needs, so if you are one of those that look at the COMAND as an out-of-date device that has little value, you may not miss it in any of the vehicles listed above. Until Daimler AG releases the appropriate Telematics update media for these devices, this will be an ongoing bug we have to deal with. It is also a test as to how much Daimler values its customer base that has not purchased new in a few years, but are still driving in some cases their flagship model and didn't expect the Telematics to have an Expiration Date. The SmartKeys we all use to start these also have a timebomb when they will stop functioning after a programmed number of uses, but it is high enough that none of us would probably hit that ceiling, but it is in there for the curious.

If having the correct date is more valuable than Navigation (for example, you have never updated your Maps) AND you know someone with Star Diagnostics, here are the steps:

(The images are attached, but are not displaying on my end - if this continues, i will place the files in another location and link to them.)
 

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Thank you for posting this, Tiffany Twisted. I am placing a link to it in the W221 DIY and FAQs, and adding it to the stickies in Audio & Telematics, and also notifying moderators of forums for affected models. Your attachments show fine on my end.

Of note, the models listed above as W208, W215, W219 and W216 are shown on the forum's first page as C208 (CLK), C215 (CL), C219 (CLS) and C216 (CL).
 

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W221 & Audio Moderator
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I hope we get more data concerning this. It will be interesting to see if large numbers of COMAND units with navigation are affected in clusters, which one might expect if the problem stems from programming. If not, I would wonder if the problem may be with a circuit component dealing with the timing from the satellites, failing to handle the reset (rollover) properly.

Konigstiger provides the following references for troubleshooting for NTG 3.0 in the W221 forum at (https://www.benzworld.org/forums/w221-s-class/3009806-analog-clock-question-2.html):
https://mbworld.org/forums/s-class-w221/728926-dash-board-clock-reset.html#post7619045
https://mbworld.org/forums/s-class-w221/727345-analog-clock-comand-aps-ntg3-problems.html
https://mbworld.org/forums/s-class-w221/728926-dash-board-clock-reset.html

Unfortunately, there may be more than just clocks and navigation affected, as TiffanyTwisted wondered.
 

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Discussion Starter #4
Not Quite The News I was hoping for on the NTG3 Time Issue

It has been acknowledged again regarding the clocks in cars from around 1999-2010 regarding defective software installed in the COMAND units causing the GPS time to not update correctly and displaying an incorrect, non-adjustable date. Daimler's official fix is the same thing we are recommending here on the boards, which is not a fix of any kind. And the date remains incorrect.
 

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