Citroën C3 Radio Code – Find & Enter Your Code

The Citroën C3 radio code is a four-digit anti-theft PIN built into the factory head unit. After any interruption to the unit's power — a battery change, a flat battery, or removal from the dashboard — the radio locks itself and displays CODE on screen, refusing to operate until the correct PIN is entered. This security feature has been present across all three generations of the C3, from the original 2002 model through to the current generation. The serial number you need to retrieve your code is printed on a C7 barcode label on the unit itself.

Why Your C3 Radio Is Asking for a Code

The lock is triggered by any loss of the permanent live supply to the head unit. Common causes include:

• Battery replacement — even a momentary disconnection activates the lock
• Battery fully discharging, dropping below the unit's threshold voltage
• Radio removed during dashboard, trim, or speaker repairs
• A blown fuse on the radio's permanent live circuit
• Buying a used C3 where the original code card has been lost or separated from the car

C3 Generations and Radio Fitments

Three generations of the Citroën C3 have been produced since 2002. Each uses a different Philips/VDO or Bosch/Clarion head unit from Citroën's PSA Group infotainment range. The RD3, RD4, and RD45 are the most prevalent units and share similar code-entry procedures.

Generation	Years	Radio unit(s)	Serial format
C3 I	2002–2005	RD3 / RD4 (Philips/VDO)	C7 barcode on unit label
C3 I Facelift	2005–2009	RD3 / RD4 / RD43 (Philips/VDO)	C7 barcode on unit label
C3 II	2009–2016	RD4 / RD45 (Philips/VDO)	C7 barcode on unit label
C3 III	2016–2021	RD5 / RT6 (Bosch/Clarion)	Serial on unit label or on-screen menu

How to Find Your C3 Radio Serial Number

The C3 uses the C7 barcode serial format on its RD3, RD4, RD43, and RD45 units. This barcode contains the unique serial number you need to generate the correct unlock code. Unlike some Renault models, Citroën's PSA-platform radios do not offer an on-screen diagnostic shortcut — the label must be read directly.

Method 1 — Read the C7 barcode label on the unit

This is the primary method for all C3 I, II, and most III models:

1. Use a set of flat plastic trim removal tools to unclip the centre console fascia surrounding the head unit. On the C3 this trim panel is typically secured by push-clips around its perimeter.
2. Insert a pair of DIN removal keys into the slots on either side of the head unit and squeeze them outward slightly to release the locking tabs. Pull the unit forward carefully — do not force it, as the wiring harness restricts how far it will extend.
3. On the top or side of the unit, locate the C7 barcode sticker. It will contain a barcode and, printed alongside it, the serial number in human-readable characters — typically a string of 10–14 alphanumeric characters.
4. Note the full serial number precisely. Scan it or type it into our Citroën radio code page to retrieve your four-digit code instantly.

Method 2 — On-screen information menu (C3 III with RD5 / RT6)

The RD5 and RT6 units fitted to the C3 III may allow serial retrieval through the unit's settings menu:

1. Switch the ignition on and allow the system to fully boot.
2. Navigate to Settings > System > About (or equivalent — menu labels vary by firmware version).
3. Look for a Serial number or Unit ID field. Note the alphanumeric string shown.
4. If the unit is locked and showing CODE rather than the home screen, the on-screen menu will not be accessible — proceed with Method 1 instead.

How to Enter the Code on a C3

All RD3, RD4, RD43, and RD45 units use the same physical button entry method. The RD5/RT6 on the C3 III supports both button and touchscreen entry depending on variant.

RD3 / RD4 / RD43 / RD45 (C3 I & II):

1. Switch the ignition to position II. The head unit display should show CODE and a row of dashes.
2. Use the preset buttons 1–4 to enter each digit. Each press increments the digit in that position by one (cycling 0–9).
3. Use the seek/right-arrow button or button 5 to move to the next digit position.
4. Once all four digits display correctly, press the OK or confirmation button to submit. The unit will unlock immediately and begin normal operation.

RD5 / RT6 (C3 III): If prompted for a code, use the touchscreen keypad to enter the four digits, then tap OK or Confirm. On variants without a touchscreen, the preset button method above applies.

Troubleshooting Common Error Messages

• CODE (persists after entry) — You may not have confirmed correctly. On RD4/RD45 units you must press the OK or confirmation button after entering all four digits — pressing just the last digit key does not submit the code.
• ERR — The code entered was incorrect. A temporary lockout will follow; wait for it to expire before retrying.
• WAIT — The unit is in its lockout period after too many wrong attempts. Leave the ignition on and wait for the display to revert to CODE before entering again.
• No display / blank screen — Check the radio fuse in the C3's main fusebox (usually in the engine bay or behind the glovebox). A blown fuse will prevent the unit from powering up at all.
• Wrong code generated — Ensure you read the full C7 barcode serial, including any leading characters, without transposing digits. A single character error will produce an entirely different code.

Frequently Asked Questions

Where is the radio code card for a Citroën C3?

Citroën supplied a small card containing the radio code in the vehicle handbook wallet at the time of purchase. Search inside the service book cover, the glove box, and any documents that accompanied the car. On used C3s the card is frequently missing; use the C7 barcode serial number from the unit to retrieve the code through our online service.

What does the C7 barcode mean on the Citroën radio?

The C7 barcode is a PSA Group (Peugeot/Citroën) identifier format printed on the radio's casing label. It encodes the unit's unique serial number in both barcode and human-readable form. This serial is the key input for generating your specific radio code — it is unique to each individual unit, not to the model or production year.

Can I enter the code without removing the radio from the dashboard?

You need to remove the unit only to read the C7 barcode serial number — and only if the original code card is lost. Once you have the code in hand, you enter it with the radio in its normal dashboard position using the preset buttons (or touchscreen on C3 III). Removal is a one-time task to retrieve the serial, not something you repeat each time you need to enter the code.

How long does the lockout last after wrong code attempts on a C3?

The RD4 and RD45 units impose a temporary lockout period after a set number of incorrect entries. The lockout is not permanent; leave the ignition on and the unit will automatically reset after the waiting period and display CODE again. The exact duration varies by firmware but is typically between 30 and 60 minutes.

Is the code the same for RD4 and RD45 units on the C3?

No. Although the RD4 and RD45 are closely related units within the PSA family, the code is generated from each unit's individual serial number — not the unit type. Two C3s with the same radio model will have different codes. Always use the serial number from your specific unit when requesting a code.

Ready to unlock your Citroën C3? Enter your C7 barcode serial number on our brand lookup page and get your four-digit code instantly — no dealer, no delay.