TL;DR
Get business pricing on garage and car supplies
- Business-only prices and quantity discounts
- Tax-exempt purchasing
- Multiple users, one account, clear invoices
A report published by a Renault Latitude owner describes reverse-engineering the car’s TomTom navigation unit after finding that its clock-setting menu was unavailable without a navigation SD card. The account says the card was protected by checks tied to its unique hardware ID and that attempts to install a modified firmware image were rejected; the supplied report does not establish that the owner ultimately changed the clock.
A Renault Latitude owner says the car’s clock-setting menu disappeared when its TomTom navigation unit had no map SD card, prompting an attempt to reverse-engineer the system rather than pay about €60 for a replacement card. The account, published November 2 on the owner’s blog, describes examination of the device’s software and failed attempts to install a modified firmware image; the supplied report does not show that the clock was ultimately changed.
The owner said the issue became apparent after Estonia moved from summer time, UTC+3, to winter time, UTC+2. The dashboard clock was then an hour out of sync. The vehicle, a 2014 Renault Latitude, displayed a “No maps found!” message because its previous owner had discarded an old navigation card.
After searching the menus and comparing them with videos of similar units, the owner found that the expected time-setting option was missing. One Settings button opened options for Bluetooth and phonebook functions; another produced a “No maps detected!” message. The owner wrote that reverse-engineering the unit supported the previous owner’s explanation: the navigation SD card carried a menu definition needed to access the Settings applet.
The blog identifies the unit as a TomTom Carminat LIVE, codenamed Beaumont, using a Samsung S5P6440 processor and a customized operating system based on Linux 2.6.28.10. The author said the system also checked a card’s unique CID and signatures tied to that ID, preventing a straightforward copy of map files onto an ordinary blank card. After finding replacement cards offered online, the owner said shipping to Estonia would bring the cost to roughly €60 and began exploring software modification instead.
The author’s initial approach was to alter the ext3 filesystem contained in a firmware update image and install the changed image. The unit accepted unmodified update images but, according to the account, would not install the modified one. The owner then set up a QEMU emulator to test the process and concluded that a separate recovery environment or verification layer might be involved. The provided source ends during the investigation and does not document a successful jailbreak or clock adjustment.
A Missing Card Blocks Clock Access
The account describes a practical problem with software features tied to map media: a driver who does not use the built-in navigation system may still need its card to reach an unrelated function. In this case, the owner said a phone already served for navigation, while the car’s dashboard clock remained wrong after the seasonal time change.
The episode also illustrates how digital restrictions can affect repair and continued use of older equipment. The author attributed the card checks to anti-piracy protection for maps, but the source does not include a statement from Renault or TomTom confirming the design rationale. The reported result is a frustrating access barrier, not evidence that all Renault systems or every Carminat unit behave the same way.
Products Worth Considering
Autel MaxiCheck MX808S Bidirectional OBD2 Diagnostic Scanner
Autel MaxiCOM MK808S Automotive Diagnostic Scanner
Autel MaxiScope MP608 4-Channel Automotive Oscilloscope
As an affiliate, we earn on qualifying purchases.
The previous owner had offered the navigation map card with the car and reportedly warned that it was needed to set the clock. The new owner initially doubted this, partly because videos of similar head units showed a clock option in their menus. The discarded card’s maps were said to be outdated and not functioning properly, and the owner did not expect to use the car’s navigation.
In the November 2 report, the owner said an earlier reverse-engineering project on GitHub helped identify where to obtain update files. Examining those files revealed a ttsystem image containing an ext3 filesystem. That investigation led the author to the conclusion that the device read its menu definition from the SD card. This is the owner’s account of one specific unit; the source does not establish how every software version or vehicle configuration handles clock settings.
The Attempt Has No Reported Finish
The supplied account stops while the owner is examining why the modified firmware image was rejected. It does not confirm a successful jailbreak, a working method to bypass the system’s checks, or a final change to the displayed time. The report also does not establish whether buying a compatible card later resolved the problem.
Other details remain unverified independently: the source is the owner’s first-person account, and it does not include comment from Renault or TomTom about why clock settings were linked to the navigation card. It is also unclear whether the menu dependency applies to other Carminat LIVE units, model years, or software versions.
Further Testing Could Settle It
The next update to watch for is whether the owner reports a successful software modification or another way to access the clock menu. The blog account describes plans and early tests, but provides no completed workaround in the supplied material. A follow-up could also clarify whether the owner chose to obtain a compatible navigation card.
For now, the documented development is an investigation into a specific car’s software, not a confirmed general fix. Owners facing the same issue would need to check their own vehicle and navigation-system version before assuming the same menu behavior or card requirements.
Key Questions
What prompted the owner to investigate the navigation system?
After Estonia switched from UTC+3 to UTC+2, the owner found the dashboard clock was an hour out of sync and could not find the clock-setting option without the navigation SD card.
Did the owner successfully jailbreak the unit?
The supplied report does not say so. It describes attempts to install a modified firmware image and investigation of a possible verification layer, but does not document a successful modification.
Why was a regular blank SD card not enough?
The owner said the system checked a card’s unique CID and used signatures tied to that ID. The report says this prevented simply copying the files to a blank card.
How much did a replacement card appear to cost?
The owner said a card found from a third-party seller would cost roughly €60 including shipping to Estonia. The report does not say whether one was purchased.
Does this affect every Renault navigation system?
The account concerns one 2014 Renault Latitude with a TomTom Carminat LIVE unit. It does not establish that other vehicles or versions have the same menu restriction.
Source: blog.nns.ee
