Sat-Nav Head Unit Locked: Code Guide

Your factory navigation head unit has gone dark — or it is showing a code prompt — after a battery swap or flat battery. Sat-nav head units fitted at the factory follow exactly the same anti-theft code rules as standard radios, and recovering the code follows the same process. This guide explains everything specific to navigation units.

Do Factory Sat-Nav Units Need a Radio Code?

Yes, in most cases. Factory-fitted navigation head units — such as the Volkswagen RNS 510, Ford SYNC with navigation, Vauxhall DVD 90 Navi, Peugeot/Citroën RT6, and Audi RNS-E — are OEM radios with an integrated navigation module. They behave identically to a standard radio when power is lost: the unit locks and requires a four- or five-digit PIN before it will function again.

The navigation maps, SD card or internal storage are separate from the anti-theft lock; they remain intact. You only need to enter the code once to restore full operation.

Common Factory Sat-Nav Units by Brand

Brand	Navigation Unit	Serial Prefix	Vehicles
Volkswagen	RNS 310 / RNS 510	VWZ (14 chars)	Golf VI/VII, Passat B6/B7, Tiguan
Audi	RNS-E / MMI 2G/3G	AUZ (14 chars)	A3 8P, A4 B6/B7/B8, A6 C6/C7, Q5
SEAT / Škoda	RNS 310 / Columbus	VWZ (14 chars)	Ibiza, Leon, Octavia, Fabia, Superb
Ford	SYNC 1 / SYNC 2 / SYNC 3	M- or V-prefix	Fiesta, Focus, Mondeo, Kuga, S-Max
Peugeot / Citroën	RT6 / RD5	C7 barcode	308, 3008, C4 Picasso, Berlingo
Vauxhall / Opel	DVD 90 Navi / Navi 600 / Navi 900	BE prefix	Astra J/K, Zafira B/C, Insignia

Finding the Serial Number on a Navigation Unit

The process is the same as for a standard radio — the serial number is on a label on the unit's body — but navigation units can be trickier to access because they are often double-DIN or integrated into the centre console.

• VW RNS 510 / RNS 310: Press and hold preset 1 and 4 simultaneously — the serial number (beginning VWZ) appears on screen for 8 seconds. No removal required.
• Audi RNS-E: The serial (AUZ…) is displayed via the unit's own menu: go to Setup → System Information. Alternatively it is printed on the label on the unit's top or side.
• Ford SYNC: The serial is on the label on the side of the unit. For SYNC 2/3 units, press the Voice button five times to access the diagnostic menu where the module serial is shown.
• Peugeot/Citroën RT6: The C7 barcode label is on the unit body. Some RT6 units also display the serial via a hidden menu: switch on, press Source and hold button 6.
• Vauxhall Navi 600/900: Press and hold the radio preset buttons 1+6 together with the ignition on. The serial appears briefly.

How to Enter the Code on a Navigation Unit

Most factory navigation units use the same entry method as their standard radio counterparts:

1. Switch on the ignition and the unit. Wait for the code prompt to appear.
2. Use preset buttons 1–4 (or 1–5) to increment each digit. Each button press advances the digit in that position by one.
3. On VW/Audi/SEAT/Škoda units, once you have set all digits, press the Seek/Scan button to confirm. On touchscreen SYNC units, tap the on-screen digits.
4. If the correct code is entered, the unit unlocks and boots normally into radio and navigation mode.

Vehicle-Bound Navigation Units: When No Code Exists

Some later factory navigation systems are VIN-bound rather than code-protected. This means the unit is paired to the car's VIN at the factory and cannot be unlocked with a code — instead it must be re-paired by a dealer using the VIN. Examples include:

• Post-2012 VW MIB/MIB2 units (Composition Media, Discover Media, Discover Pro with Komponentenschutz)
• Ford SYNC 3 on 2018+ vehicles (dealer activation via FordPass Connect)
• Fiat Uconnect / Live systems
• Most Mercedes-Benz COMAND NTG5 systems

If your sat-nav displays a message such as "Component Protection" or "Contact Dealer" rather than a numeric code prompt, it is VIN-bound and requires dealer assistance.

Retrieve Your Sat-Nav Code Now

For all factory navigation units that use a PIN code, you can select your car brand at radiocodelookup.com/brands, enter the serial number from the unit label, and receive your code instantly. The process is the same for sat-nav units as for standard radios — the serial number is the only input required.

Frequently Asked Questions

Will entering the radio code delete my sat-nav maps?

No. The anti-theft code lock only affects whether the unit powers on. Your navigation maps — stored on an SD card, DVD or internal NAND flash — are completely unaffected by entering or failing to enter the code.

My VW RNS 510 shows SAFE after the battery was disconnected. What do I do?

Wait approximately one hour with the ignition on and the radio powered up. The display will change from SAFE to 1000, indicating it is ready to accept the code. Use preset buttons 1–4 to set each digit, then press the Seek button to confirm.

Can I use the code from my standard radio on my RNS navigation unit?

No. Each unit has its own unique code tied to its own serial number. A navigation unit and a standard radio fitted to the same car will have different codes.

My Ford SYNC says LOCKED — is it code-protected?

Older SYNC 1 and early SYNC 2 units do use a radio code. Later SYNC 3 units on post-2017 Fords may use a VIN-binding system. Try obtaining the code via our Ford page first using the M- or V-prefix serial number.

The display shows a six-digit serial instead of a four-digit code prompt. What does this mean?

You are likely reading the unit serial number displayed on screen via a shortcut, not a code prompt. The code you need to enter is a separate four- or five-digit number generated from that serial. Use our lookup tool to convert the serial to the unlock code.