Mercedes COMAND Diagnostic

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Transcript of Mercedes COMAND Diagnostic

Mercedes COMAND Diagnostic (


) Mode

Version 1.6 10 Dec 2008

Add more info about interlocks Add info about Comand 2.5 Correct links for new mercupgrades website correct CTEL2 value tidy up add exit instructions

Version 1.5 7 th October 2007 Version 1.4 12 th May 2007 Version 1.3 25 th March 2006 Version 1.2 25 th March 2006 Version 1.1 25 th March 2006


Mercedes COMAND 2.0 (i.e. CD based COMAND) system has a whole set of hidden diagnostic menus.

Diagnostic mode is also available on COMAND 2.5 (the original S/CL class COMAND version with a tape deck) but will be subtly different to those described below.

These menus are useful when trying to ascertain if there is a fault with your COMAND system, however, nothing can be altered from these menus.

To enter diagnostic mode, press SYS and then select the AUX input by turning the right hand rotary knob to highlight Aux and pressing the rotary knob.

Then hold down the following 3 keys for about 10 seconds.

MUTE, 1, 3

(NB, on the Comand 2.5 do this in TV mode as there is no AUX mode)

You will then see the following screen: -

On COMAND 2.5 (old S-Class/CL units), it may be possible to enter this menu if you select TAPE input as there is no Aux input.

The rest of this document describes what information is in the various screens/menus that can be access in Service Mode.

The RET key acts as a previous screen key so to exit service mode, just hit the RET button when the menu above is showing.


Entering this menu allows you to see the software and hardware versions of COMAND. Select the menu you want with the right hand knob , and use RET key to go back to the previous menu list.

Here is an example from the Processors menu, this is a COMAND 2.0 E class unit with the MY2001 software update applied

The most useful screen here is Infos as it tells you if the vehicle is seeing the speed impulse and how many satellites are being received. If you have a different looking Infos menu, it is because you have not applied the MY2001 software update to COMAND which you should so.

TUNER menu

This returns you to the FM/AM main screen, but also shows an extra line showing the currently tuned stations frequency and signal strength (0-10). Remember that in Europe the main line normally shows the RDS station name.


This allows you to see various co nfiguration items, including the error list, to reset the COMAND system, and to look at the D2B status.

The Error list initially shows the list of errors that the dealer s Star Diagnosis machine would see, holding MUTE and 1 switches to the internal list. MUTE and 4 returns to the original list, MUTE and 0 clears the error list.

The meaning of

the SAE-Code in the error list can be found at: - COMAND error codes

The Type field is part of the error code, and in the list of error codes is shown after the / in the error code For instance B1912/8 would have B1912 in the SAE-Code column and 0x0008 in the Type column.

The Cnt figure is useful as it tells you how many times an error is occurring. The State value tells you whether the fault has happened Previously or if the fault is currently Active.

Selecting System Reset resets the COMAND unit.

The D2B components list shows what is Actually found on the fibre optic bus, and what the system is Configured on the bus. If the unit has been properly configured by the Mercedes dealer, then these should match each other, and match what extra options you have in the vehic le.

The 3 digit numbers shown are: 1C8 108 190 0F0 0F1 1F8 1B0 0E0 COMAND Digital BOSE AMP CD Changer Phone CTEL2 (e.g. 2nd phone in S class) Voice Recognition Satellite Radio Module (USA) Teleaid Control Module (USA)


This shows how various options are configured on the COMAND system.

There are various tickboxes, TV-Tuner units Telephone (expand) Enables SMS functionality on phones Telematic Enables TCS (nothing to do with TMC) TV tuner is enabled enables TV button on US

Telematic over D2B ditto Analogue Bose Tells system analogue bose amp connected

Combi-Self-Aligned Tells COMAND whether the instrument cluster will self centre any text that is sent to it or not

And, on the bottom line is 6 alpha-numeric digits (hexadecimal) (20 6D 04) in the above case - The last digit (4) in the above example configures which interlocks are in place to prevent the TV being watched whilst the vehicle is in motion the other digits control various features, some of which are in the tickbox list.

Here is a table of what some of those interlocks mean.

First Byte (20 hex in above) Bit Bit Bit Bit Bit Bit Bit Bit 7 (MSB) 6 5 4 3 2 1 0 (LSB) Analogue Bose SMS Sending disabled Always Set

Telematics (EU) / Starguide (USA) TV tuner

Second Byte (6D hex in above) Bit 7 (MSB) Bit 6 Bit 5 Bit Bit Bit Bit Bit 4 3 2 1 0 (LSB) Telematic via D2B Telephone with expanded functions Instrument cluster with self centering text (combi self aligned) Always Set Always Set Always Set

Third Byte (04 in above) Bit Bit Bit Bit Bit Bit Bit Bit 7 (MSB) 6 5 4 3 2 1 0 (LSB)


disabled disabled disabled disabled

at speeds > 10km/h at speeds > 2km/h if not in Park / Neutral if handbrake off

Also on the bottom line is the setting telling the COMAND how many impulses per wheel rotation the car will send the COMAND unit, this is also in hexadecimal, so 30 means 48. Remember that with some cars the speed is sent over the car s network (CANbus) rather than with a speed signal wire, so in some cars this can be set to 0.

Here is a list of the DTC (error) codes that COMAND can generate. These can be seen via the hidden diagnostic menu.

B1000 Control Unit A40/3 (COMAND) is faulty B1002 Internal CAN databus error (RB Can) B1003 Interior CAN databus error (CAN B) B1010 The supply voltage of the control unit is too low B1730 Excess temperature of CD player B1734 No speed pulses from traction control module B1736/1 B1736/2 Fault in reading CD-ROM drive general CD read error, navigation CD unreadable Fault in reading CD-ROM drive - CD data block read fault. replace unit) (may not need to

B1736/4 B1736/8

Fault in reading CD-ROM drive read error CD timeout reading data block Fault in reading CD-ROM drive Check CD in player (may not need to replace unit)

B1736/16 B1738/1 B1738/2 B1738/4

Fault in reading CD-ROM drive Check CD in player (may not need to replace unit) Navigation Fault: GPS report not received Navigation Fault: GPS aerial short to positive or ground Navigation Fault: GPS aerial open-circuit

B1761 Cable fault: short circuit of switching line Ant ON B1762 Fault in CAN communication with A40/3n2 (Navigation processor) B1765 Component A40/3 (COMAND) is faulty B1766 Lost Navigation data B1767/0 B1767/1 B1769/4 B1769/010 Navigation parameter missing number of teeth of ABS pulse rotor not configured Navigation parameter missing wheel size / height ration Internal traffic data memory: Function software Fault Internal traffic data memory: Fault in communication with CTEL or Teleaid

B1779 Fault in CAN communication with TV Tuner B1780 Fault in CAN communication with Instrument Cluster B1795 Fault in CAN communication with EIS control module N1111/x No data transfer between D2B master and D2N component. The component at location x reports a fault in the D2B ring

N1112 No data transfer between D2B master and D2B predecessor component possible N1113 No D2B data transfer possible, position can not be located N1114 Address initialisation of the D2B master faulty N1115/x A D2B component could not be integrated in the system The component at location X reports a fault in the D2B ring Failure of D2B component in position X in D2B ring At least one button is sticking for longer that 120 seconds

N1116/x N1132

N1141 Set/Actual configuration of D2B ring differs N1204/1 N1204/2 N1204/4 Telephone fault with dynamic navigation -No GSM signal detected Telephone fault with dynamic navigation -No portable recognised Telephone fault with dynamic navigation -No PIN entered


Telephone fault with dynamic navigation Directory fault

Note, N1204/xxx errors are only logged if TCS has been enabled (i.e Telematic Via D2B in the configuration register), and will be logged if the phone has been disconnected etc.

You need to firstly remove the wood (or metal) centre console trim, The pictures below are for the pre MY2005 facelift, however the procedure is the same on newer cars except that you must open the cupholders, remove the front piece and close them again. On MY2009 cars to remove the COMAND you must also remove the airvents above to access the screws that hold the top of the COMAND unit.

Firstly remove the trim either side of the centre console. Lower the seats to the lowest and most rearward position to give best access, and then remove the trim which just pulls off from the centre console and then slides out from the dashboard. Put your fingers under the trim (above the carpet) in the middle and pull gently to release the middle clips, work your way backwards until all the clips are released and then pull the trim out (pulling to the rear of the car away from the dashboard). Here is a picture of the trim removed, circled are the hooks that hook into the dashboard, you can also see all the clips that hold the trim to the centre console and the other two metal clips that lock it into the dashboard.

Now unscrew the 3x TORX TX20 screws on each side that hold the wood/metal trim to the centre console