Satellite navigation systems are extremely important, especially for those who like to travel to new places or for the poor souls who have a very bad sense of direction. Funny stories about sat nav blunders are everywhere and most are hilarious until it happens to you.For example, these 2 travellers were trying to get to Capri but mistakenly typed “Carpi” into their sat nav and ended up 400 miles off Capri… What a nightmare! Of course, in this incident, the problem was not the actual sat nav. For what it’s worth, their sat nav was working really, really well. Who knew a simple mistake like a misspelt destination would take them totally off their route. But setting the jokes aside, sat nav issues can be quite serious, as we trust and use these devices to accurately guide and take us to the places we need to go.Here are some of the most common sat nav issues, including possible solutions:
No signal. A clear line of sight between your sat nav and the satellites it is using is necessary, in order for your navigation equipment to work properly. To get a proper fix of your location, you need to be in the line of sight of at least 3 GPS satellites. Factors such as weather and location can affect the signal strength, so typically when there is an intense weather condition, your sat nav will probably not work, however, that’s where offline maps come in. Possible Solution #1. Download offline maps before you set out. If you frequently update your these maps once they’re downloaded, it might just save the day if your sat nav loses signal. Possible Solution #2. Update your sat nav software. Making sure your sat nav is up-to-date is important. Software and firmware updates can be found on your device’s website. Possible Solution #3. If an update does not do the trick, do a soft reset on your GPS device. Doing a soft reset is not complicated and you will only lose your timezone settings and any customisations you may have made. With a paper clip press the reset button, which you can find at the back or under your device. Possible Solution #4. Do a force restart. For some Garmin devices, you can achieve a force restart by pressing and holding down the power button. Other Garmin devices can reset themselves when the battery is removed and then inserted back in, just like in a traditional mobile phone. Possible Solution #5. Do a hard reset. Unlike a soft reset, a hard reset reverts your device’s settings to default factory settings. Before performing this, eject your SD or mini SD card and back up your information because a hard reset will erase all your settings and data. Possible Solution #6. Hardware issues. Like most devices, sat navs are vulnerable to extreme heat. If your device is overheating, take the unit out to regulate the temperature, then try again. Possible Solution #7. Antenna issues. After performing solutions #1-6 and your device still has no signal, chances are there are some internal issues. If your device has serious internal issues you could take it to a service centre where technicians could replace any damaged or broken parts. Wrong location. If your sat nav is showing the wrong location, whether by a few meters or by miles, you might be experiencing some serious positioning issues. Possible Solution #1. Visit your device’s website and update the software and firmware to it’s most recent release. Possible Solution #2. Take your device to the service centre for recalibration. Dim lighting on screen. Some of the common complaints were about the dim lighting on the sat nav. Possible Solution #1. Check the power settings. Most likely, your power settings are on battery-saving mode. When this option is on and the battery is low, the screen display will automatically lower, therefore, making it dimmer. To avoid your device from automatically dimming itself when on battery mode, you have to unselect that power setting. Keeps freezing and crashing. If your sat nav keeps freezing and crashing, it may be due to some corrupted file. Possible Solution #1. Hard reset your device and reinstall if a soft reset does not fix the problem. Possible Solution #2. Format your device. Make sure you create a back-up of the settings before doing so. Unresponsive screen or touch icons not working. This is an indication of issues with the touch sensor. Possible Solution #1. Using an ATM card, lift the bezel around the touch screen. Lift it just high enough to get a few toothbrush bristles in, carefully work the bristles around the screen and observe if anything falls out. If you see grains or tiny grit, know that these are enough to mess up your screen sensitivity. If nothing falls out, use a can of air with a fine nozzle on and blast some air through as you lift the bezel. If that does not work, proceed with the next solution. Possible Solution #2. Take your device to a certified service centre and get a proper diagnostic. Chances are your screen and digitizer are up for replacement. Continuously rebooting. When your sat nav keeps on rebooting, there are two possible reasons: your battery is defective or corrupted data. Possible Solution #1. When your sat nav does not have enough power to run all systems, it will resolve the issue by restarting. To determine if your device’s battery is the culprit or your car charger is faulty and defective, reset your sat nav, connect it to your computer and charge for 4 hours. If it works, your charger is most likely defective. Possible Solution #2. If your device is rebooting, the map is probably corrupted. If the map is corrupted, you need to run a clear flash tool on your device. Restart the device and connect again. Possible Solution #3. If the first two possible solutions do not solve the rebooting problem, that could mean the memory is faulty.To prolong the life of your sat nav, make sure you do the following:
- Protect it from direct sunlight.
- Prevent your sat nav from overheating. This can be done by trying to keep your vehicle cool, in order to regulate the temperature of your device.
- Keep your sat nav away from water or any other liquid.
- Do not clean your sat nav by wiping it with just an ordinary cloth. It is best to use a lens wipe. If your sat nav fell on some mud, slightly wet a chamois cloth and use that to wipe the back and side parts of the sat nav. Use a lens wipe to wipe the screen.
- If you need to use your sat nav outside of your vehicle, make sure it is enclosed in a hard case, to ensure your device is protected in case you accidentally drop it.
- Make sure that the case is also waterproof.
Why is my built-in sat nav not working? Make-by-make faults & fixes
Everything above applies to a portable, handheld sat nav — the kind you mount on the windscreen and can unplug. A built-in, factory-fitted navigation system is a different animal. It is wired into your car’s electronics, shares power and data with the rest of the vehicle, and cannot simply be swapped for a new one from a shop. When a factory nav unit plays up, the make and the specific system matter, because the fault patterns — and the fixes — differ from one manufacturer to the next. Below we work through the built-in systems we repair, the symptoms drivers actually report, the steps you can try yourself, and the point at which the unit needs proper component-level attention.
Volkswagen, SEAT & Škoda — Discover Media, Discover Pro & RNS
Volkswagen, SEAT and Škoda share the same infotainment platform, so faults look alike across all three badges. Newer cars run the MIB system — Discover Media and the higher-spec Discover Pro — while older models use the RNS 310, RNS 315 and RNS 510 units. Škoda badges its versions Amundsen and Columbus; SEAT uses the Media System and Navi System names for the same hardware.
The symptoms drivers report most often are:
- The screen boots to the VW badge and then freezes.
- The nav shows the wrong location or drifts off the road.
- A ‘no GPS signal’ message on a screen that otherwise works.
- A black or frozen display, or a unit that is completely dead.
Try a reset first. Press and hold the power/volume knob for around 10 to 30 seconds until the screen goes black and the badge reappears — this reboots the unit without wiping your settings. If the maps are out of date or a wrong-location fault persists, install the latest map and firmware update; VW, SEAT and Škoda publish these for each specific unit, usually on SD card or through their online update portal.
When a reset and an update change nothing — the screen stays black, an RNS 510’s hard drive or disc laser has failed, or the unit is dead — the fault is in the hardware, and no amount of rebooting will bring it back. At that point the module needs component-level diagnosis and repair to fix the fault on your original unit.
Audi — MMI & RNS-E
Audi’s built-in navigation runs through MMI, the Multi Media Interface controlled by the rotary dial and buttons on the centre console. Older A3, A4 and TT models used the DVD-based RNS-E unit instead.
Common Audi symptoms include:
- ‘Sat Nav initialising, please wait’ that never finishes.
- Media and navigation both stuck on ‘initialising’.
- A black MMI screen while the driver’s display still lists the system.
- A frozen or lagging screen, or a ‘navigation data are not enabled’ error.
To reset the MMI, press and hold the power/volume knob — or use the button combination for your generation — until the system restarts; on some cars, cycling the ignition once the unit has fully powered down helps it recover. If your maps are old or the position is wrong, update the MMI map database and software to the latest release Audi issues for your MMI generation.
If the MMI stays stuck on ‘initialising’, boots to a black screen, or keeps dropping out, the fault is in the MMI control unit or its internal hardware rather than the settings. A unit like that is repaired at board level, so you keep your original MMI instead of paying for a full dealer replacement.
BMW & Mini — iDrive (CCC, CIC & NBT)
BMW and Mini navigation runs on iDrive, worked by the rotary controller between the seats. Over the years that has meant several head units — CCC (Car Communication Computer), the later CIC (Car Information Computer) and the current NBT and NBT Evo generations — alongside the screen BMW calls the Multi-Function Display.
Reported faults include:
- The map stuck on a spinning wheel or the word ‘starting’.
- Navigation that will not load at all.
- The wrong location shown on the map.
- A black or frozen screen, or missing map data after an update.
Start with a reset: hold the volume/power knob — or the volume rocker on some models — for 20 to 30 seconds until the screen goes blank and iDrive reboots. If the maps are missing new addresses or roads, check the map version installed in your car and update it to the current data BMW publishes for your iDrive generation.
When iDrive still hangs on the badge, the screen stays dark, or the head unit or display has failed outright, the problem is hardware. We repair BMW iDrive and the Multi-Function Display (MFD) satellite navigation unit at component level, correcting the fault on your original unit rather than replacing the whole system.
Mercedes-Benz — COMAND
Mercedes-Benz built-in navigation is part of COMAND — the Cockpit Management and Data system — fitted across the range through its NTG generations.
COMAND faults are frequently hardware-led:
- The screen cycles through the Mercedes badge, then drops out after a few minutes.
- The display goes completely blank.
- The map is lost while the radio still plays.
- The unit will not power up at all.
A reset is still worth trying: hold the power button for around 10 to 15 seconds to reboot COMAND, and on some models pulling and reinserting the head-unit fuse clears a software glitch. If the maps are outdated or the position is wrong, load the latest COMAND map update for your NTG version.
Where the screen keeps going blank, the unit restarts on its own, or it will not switch on, the internal hardware has failed — on many COMAND units this traces to ageing internal components on the board. That is exactly the kind of component-level repair that returns your original COMAND unit to full working order.
Ford — SYNC, SYNC 3 & MFD
Ford’s built-in navigation comes in two main forms: the SYNC system — SYNC and the touchscreen SYNC 3 — and, on older Focus, Mondeo and Galaxy models, the Multi-Function Display (MFD) navigation unit.
Typical Ford symptoms are:
- A ‘no GPS signal’ warning or a red GPS indicator.
- Navigation that is slow or cannot find a fix.
- A black SYNC screen.
- A unit that has stopped responding.
For a lost signal, toggle the location setting off and back on, then perform a SYNC module reset followed by a key cycle — turn the car off, open the door and let it stand for a couple of minutes before restarting. A master reset from the settings menu clears deeper software faults, and a soft reset on SYNC 3 is done by holding the Power and Seek buttons together until the screen restarts. Keep the system current by installing the latest SYNC software and map update by USB from Ford’s update site.
If the screen stays black, the module will not reset, or the nav still cannot find GPS after all of that, the fault is in the unit or its GPS hardware. A failed SYNC or MFD module can be diagnosed and repaired at component level, so your original Ford unit goes back in the car.
The pattern is the same across every make: a reset or a map update cures a software hiccup, but a dead screen, a unit that will not power up, or a fault that keeps returning is a hardware failure that rebooting will never fix. That is the work we do — diagnosing and repairing built-in navigation units at component level in an ESD-safe workshop, then returning your original unit tested and ready to fit.
Whatever the make, you can send your unit in through our sat nav repair service. If you are not sure which fault you are dealing with, start a repair enquiry or get in touch and we will help you work it out.
Frequently Asked Questions
Why is my sat nav not working?
A sat nav usually stops working because something is interrupting its GPS fix or because its software needs attention. The most common causes are:
- A weak or obstructed GPS signal — the device needs a clear line of sight to at least three satellites, and weather or your location can weaken it.
- Outdated maps, software or firmware.
- An antenna fault or another internal hardware problem.
- A corrupted file or software glitch, causing freezing or constant rebooting.
- A failing battery or a faulty charger.
Why does my sat nav keep losing signal?
Your sat nav needs a clear line of sight to at least three GPS satellites to fix your position accurately. Tall buildings, tunnels, dense tree cover and intense weather can all block or weaken that signal, so the device drops out. Downloading offline maps before you set off keeps you navigating even when the live signal disappears.
How do I fix sat nav signal problems?
Start by downloading offline maps before you travel, then check your device’s website for any software or firmware updates. If the signal still drops, try a soft reset using the small reset button on the back or underside of the unit — this only clears your timezone and any customised settings. If that fails, a hard reset restores the original factory settings, so eject your SD card and back up your data first.
Why is my sat nav showing the wrong location?
A position that is out by a few metres or by miles usually points to a calibration or software problem rather than a lost signal. Visit your device’s website and update the software and firmware to the most recent release. If it still misreads your location, the unit may need recalibrating at a service centre.
How do I update my sat nav maps?
Map, software and firmware updates are published on the manufacturer’s website for your specific device — download and install the latest release. Keep your offline maps refreshed afterwards so they are ready if you lose signal on the road. Running the most up-to-date maps also helps prevent wrong-location errors and the freezing that outdated or corrupted files can cause.
Can a built-in (factory) sat nav be repaired?
Yes. Many handheld sat nav faults can be sorted at home with a reset or a software update, but a built-in, factory-fitted navigation system is part of your car’s electronics and needs to be diagnosed and repaired properly rather than reset. At Sinspeed we repair in-built navigation systems, fixing faults at component level so you can keep your original unit instead of replacing it.