Unlock Code Calculator

This online calculator will provide the original security code for Media Nav units, as well as most Dacia and Renault radio units, requiring only the last 4 characters of the serial number, called the security precode. The format is always LDDD, meaning an uppercase letter, followed by 3 digits, the first digit always having a non-zero value. This precode may be found alongside the word SECURITY. Input the precode here and press CALCULATE:

Security code:

The uppercase letter goes from A to Z, while the digits go from 100 to 999. There are 900 digits combinations for each of the 26 letters, giving a total of 23400 combinations and their respective security codes. Yet, since the security code itself has only 4 digits, there are only 10000 possible security codes, but trying them all will prove fruitless, since all radio and multimedia units employ a limitation. In the case of Media Nav units, the time between code input attempts is regulated by the formula 2^n, where n is the previous attempt number (starting from 0) – the second attempt will be possible after 1 minute (2^0), the third after 2 minutes (2^1), the fourth after 4 minutes (2^2) and so on.

Locating the serial number and security precode

The serial number is located on a sticker that should be found on the site or the back of the radio or multimedia unit. The format and length may vary, but is almost always located under a barcode and ends with an uppercase letter followed by 3 digits. This last 4 characters are the security precode needed to calculate the security code. The sticker format varies from device to device; the following image should give some clues of what should be looked for – the precode is highlighted with red rectangles:

Needless to say, to most time consuming part is dismantling the device from the dashboard. The procedure is different for each vehicle model and device, with newer models being harder to take out.

In some cases, an alternative may be suitable:
– older radio units should display the security precode if buttons 1 and 5 are pressed while turning on the device;
– for second generation Media Nav units (MN2), the Code Recovery Tool (MN2) could be used to get the security code directly.