15 problems with the Comand APS NTG2 navigation system in a Mercedes

Last updated: 19 October 2025 (content)

Definition: The Comand NTG2 system is a second-generation factory multimedia unit fitted in Mercedes models (such as ML164, W245, W203, W209, W169, W164, W251). It combines navigation, radio, CD/DVD player and, optionally, changer, phone and amplifier into one system based on a MOST fibre-optic loop, i.e. a bus connecting the audio devices.

You see a black screen. Or, worse, the radio seems to have a mind of its own — restarting whenever it feels like it, or freezing on the Mercedes logo. Suddenly the whole entertainment and navigation control centre in your car becomes useless. It is frustrating, especially when you have a long journey ahead or simply want to listen to music.

If your navigation freezes on the logo, see our guide to Comand NTG2 comprehensive repair

A problem with the Comand NTG2 system is not just about losing maps or radio. Often there is a whole range of irritating symptoms: from crackling in the speakers, through the battery going flat overnight, all the way to the unit being completely "dead".

The good news is that we know most of these faults very well and in 99% of cases we can repair them effectively. In this article, we have collected the 15 most common Comand APS NTG2 problems. It is worth checking which one applies to your car and seeing what is most likely causing it.

How do you identify a Comand APS NTG2 unit?

Before you start diagnosing the fault, it is worth making sure you are dealing with an NTG2 system.

Key features:

• Appearance: It has a colour screen, a DVD navigation drive located in the boot (or under the seat) and a separate CD/DVD drive in the main unit.
• Car models: Factory fitted, among others, in:
  • Mercedes E-Class (W211) from 2002 to 2009
  • Mercedes CLS (C219) from 2004 to 2008
  • Mercedes SLK (R171) from 2004 to 2008
  • Mercedes ML (W164) from 2005 to 2008
  • Mercedes GL (X164) from 2006 to 2008
  • Mercedes R-Class (W251) from 2005 to 2008
  • Mercedes A-Class (W169)
  • Mercedes B-Class (W245)
  • Mercedes C-Class (W203) after 2004
• Part numbers (Part Number): They usually start withA164..., A211..., A169..., A203...(e.g.A164 820 09 79).
• Still not sure whether your radio is a Comand NTG2? Send us a photo of the front, and we will confirm the model.

15 most common Comand APS NTG2 faults

Below you will find a list of problems that customers most often bring to us.

1. Black screen (no content on the display)

• Symptom: You start the car, but the navigation screen stays black and shows no content. In some cases the radio works in the background, so you can hear the station, but the image does not appear. Customers often describe it as the final stage of a fault: "The Mercedes-Benz logo appears, then disappears and nothing happens" or "The Mercedes logo comes on, then the display goes black".
• Cause: Most often this is a symptom of a critical hardware fault on the main board, so-called cold solder joints. In practice, such a problem causes communication interference and prevents the system from loading the graphical interface.
• Solution: Find out more about the causes and refurbishment of this fault

2. Freezing on the Mercedes-Benz logo

• Symptom: This is one of the most commonly reported faults. When the ignition is switched on, the "Mercedes-Benz" logo appears on the screen and that is where the unit stops working. Customers describe it, for example, like this: "The radio turns on and displays the Mercedes logo, and after a moment the display goes dark" or "The Mercedes logo appears for 30 seconds and then switches off".
• Cause: This is a classic sign of a hardware fault on the main board, i.e. so-called dry joints. The system is unable to complete the start-up procedure because of communication errors.
• Solution: See how we refurbish this module step by step

3. Continuous restarts, i.e. a restart loop

• Symptom: The radio is literally “doing its own thing”. Customers often describe it as “cycling”: “It turns itself on and off. Sometimes it works for a few minutes, switches off, and after a while starts up again by itself”. The unit tries to start, shows the logo, then goes dark and tries again, getting stuck in a restart loop.
• Cause: This can also be a sign of instability caused by “dry joints”, i.e. micro-cracks in soldered connections. In other words, the problem may also affect communication on the MOST fibre-optic loop.
• Solution: Check out our DIY guide, where we show how to diagnose the MOST loop

4. Freezing or noticeably slower operation

• Symptom: The system responds very slowly to your commands. Changing the radio station takes several seconds, the map stutters while moving, and entering an address in the navigation becomes almost impossible.
• Cause: This is very often an early warning sign of a hardware fault on the main board, the so-called dry joints, i.e. unstable connections. Over time the fault usually gets worse and can lead to restarts or freezing on the logo.

5. Draining the battery

• Symptom: You leave the car overnight and in the morning the battery is completely flat. This happens because the radio does not “go to sleep” properly after the ignition is switched off. It often gets stuck in a loop of silent restarts or simply draws current while parked.
• Cause: A hardware fault on the main board, most often related to “dry joints”, which prevents the unit from entering sleep mode.

6. Software errors, e.g. incorrect time or losing stations

• Symptom: You notice small but very irritating faults: the system loses saved radio stations after every start, resets sound settings such as bass and treble, or stubbornly shows the wrong time.
• Cause: This is another sign of damage to the flash memory on the main board, i.e. the circuit responsible for permanently storing data. In practice, this leads to software instability and problems saving settings.

7. Won't read CD/DVD or won't accept the disc

• Symptom: You insert a music CD and the drive “chews” it for a moment — you can hear the mechanism working — then spits it out or shows a read error. It can also “eat” discs, meaning it will not accept or eject them.
• Cause: This is usually due to natural wear of the laser or the drive mechanism itself in the main unit. In practice, the repair comes down to replacing the drive module with a working one.

8. Navigation does not work (map), white screen

• Symptom: You try to switch on navigation (the “NAVI” button), but instead of the map you only get a “white screen”, as if the system were unsuccessfully trying to load the data. Other functions, such as radio or CD, may work correctly.
• Cause: This is a fault related to the map reader. Most often the problem is a faulty DVD drive (the one in the boot or under the seat), which cannot read the map disc.

9. Cannot see GPS satellites or loses signal

• Symptom: The map is displayed, but your position remains “frozen” — often in Germany, in Stuttgart — or does not update while driving. In the diagnostics menu, the number of visible satellites is 0.
• Cause: Most often this is due to a faulty GPS aerial (e.g. after a visit to the car wash or due to moisture). Less often, the cause is damage to the “Sirf Star” circuits (GPS module) on the radio main board.

10. Sound fault (cuts out, crackles)

• Symptom: The sound can cut out, you hear loud crackling or “pops” from the speakers, even with the radio muted. It can also disappear completely from all speakers.
• Cause: This depends on the equipment:
  1. In the system with Harman Kardon (Logic7) sound: In practice, in 99% of cases the culprit is the external amplifier, usually due to moisture.
  2. In the standard system (without HK): The cause is “dry joints”, i.e. weakened soldered connections, in the NTG2 main unit.

11. Buttons or potentiometers do not work

• Symptom: The buttons on the radio panel (e.g. “RADIO”, “NAVI”) or the knobs (volume, selection) stop responding. You turn the knob and the volume does not change or jumps.
• Cause: This is a rather misleading symptom. Most often it does not mean a fault with the radio itself, but damage to another module on the MOST fibre-optic loop (e.g. the Harman Kardon amplifier or the telephone module). The faulty module blocks communication, which means the radio starts to “go mad”.
• Solution: It is worth taking a look at our DIY guide, which shows step by step how to confirm a fault on the MOST loop yourself

12. Bluetooth does not work or will not connect to the phone

• Symptom: You try to pair a phone, but the system cannot see it. The menu may show the message “No Phone” or the “TEL” function remains inactive (greyed out).
• Cause: NTG2 did not have built-in Bluetooth. This function was provided by an external module (most often in the armrest). In practice, the cause is almost always damage to that module itself, not to the main unit.

13. Problem with the CD changer

• Symptom: We are referring to a separate changer (magazine), usually fitted in the glovebox. The unit does not “see” the magazine, does not take discs, or you cannot remove them.
• Cause: It is usually a mechanical fault in the changer itself (e.g. a jammed mechanism, faulty laser or electronics).

14. Damaged AUX socket

• Symptom: You connect your phone with a cable to the AUX socket (usually in the passenger glovebox), select “AUX” in the radio menu, but there is still no sound. It can also happen that the sound is distorted, crackles, or plays only on one channel (left or right).
• Cause: This usually means physical damage to the AUX socket (for example broken pins in the socket) or a worn connection cable.

15. Display damage (lines, spots)

• Symptom: White lines white stripes appear on the screen — horizontal or vertical — dark spots, or “leaked” dead pixels. It can also happen that the image fades in sunlight or at higher temperatures. It is worth noting that this problem usually does not concern the software, but the screen itself.
• Cause: Damage or wear of the LCD matrix, that is, the panel responsible for displaying the image. In practice, this means it needs replacing with a new one.

About the author of this article

This article was prepared by the technical team at OEMatic workshop. We specialise in advanced diagnostics and repair of factory radio-navigation systems from premium brands, especially in vehicles based on the MOST architecture, that is, the fibre-optic communication bus. We have many years of experience and have refurbished hundreds of Comand APS NTG2 units.

Have you recognised your problem?

If any of the 15 problems described above sounds familiar, it is worth not waiting until the fault gets worse or the radio completely drains the battery.

Most of these faults, especially problems with the main board — that is, the device’s central electronics module — are standard repair work for us. In practice, this means effective refurbishment instead of an expensive replacement at an authorised dealer.