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MB Paul
MB Paul, Mercedes Technician
Category: Mercedes
Satisfied Customers: 4317
Experience:  Mercedes Benz Qualified Diagnostic Technician
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Hi , The NAV.unit on my clk(NNN) NNN-NNNNyear displays " Fatal

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Hi , The NAV.unit on my clk(NNN) NNN-NNNNyear displays " Fatal Exception Error " How do i fix this please .

This is an internal fault in the COMAND unit - although you have tried removing the fuse I would physically remove the COMAND and disconnect the power completely as the system also has unfused power supplying it as well and to do a hard reset requires the unit to be disconnected completely.

If the fault still remains then I would always recommend a check on Mercedes STAR diagnostic tool to check for codes and to try a reboot on the fibre optic ring to see if this has an effect.

If not then it may be possible to have your unit repaired - I have had some success with our local car audio repair specialist. It really depends on the exact cause of the fault & what parts are available for the repair.

Here is also a link to a company that can supply remanufactured units - I would contact them to see if they can supply a unit for you as another alternative: BBA Reman

Best regards, Paul
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