2004-2010

Radio Code Citroën C4 I

Citroën and Peugeot share more than a factory — the radio is identical too. The Blaupunkt RD4 in the C4 I works exactly the same as in a 307 or 207, including the BP serial number and the four-digit code.

Summary

Brand: Citroën
Generation: C4 I
Production years: 2004-2010
Standard radio: RD4; Blaupunkt
Radio option 2: RD3; Clarion / VDO
Radio option 3: RT3; Magneti Marelli

Which radio is in your C4 I?

The Citroën C4 I (2004-2010) was fitted with the standard PSA radio platform. Depending on the year of manufacture and trim level:

Blaupunkt RD4 — Present in the vast majority of C4 I examples. Single DIN, CD player, RDS, green or amber LCD. Recognisable by the four preset buttons to the left of the display. Serial number: BP + fourteen digits.

Clarion or VDO RD3 — Some early C4 I models (particularly 2004-2005) still had an RD3 fitted. Clarion variant: serial number starts with C7. VDO variant: its own format, sometimes VIN-linked.

Magneti Marelli RT3 — The optional navigation system in higher trims. Double DIN, built-in. This system is VIN-linked and does not have a traditional radio code. Problems with it require PSA DiagBox.

Note for Clarion RD3 owners: Almost all Clarion radios for Citroën are not decodable via the serial number, even though the number starts with C7. The exception is older vans. If your C4 I has a Clarion RD3 and you have lost the code, contact a Citroën dealer.

Radio	Year	Serial number	Decodable
-------	------	---------------	-----------
RD4 Blaupunkt	2005-2010	BP + 14 digits	Yes
RD3 Clarion	2004-2006	C7 + 10 digits	Limited
RD3 VDO	2004-2006	Own format	Limited
RT3 Magneti Marelli	Optional	VIN-linked	No

Recovering the radio code

Citroën supplied an anti-theft card with every new car — a small card showing the radio's serial number and the corresponding code. Look:

In the document wallet — with the owner's manual or audio guide
Inside the glovebox — previous owners or dealers sometimes stuck a sticker here
With the spare key — sometimes kept in the same envelope

No card? Then the radio has to come out to read the label.

Removing the radio from the C4 I

The Blaupunkt RD4 and RD3 are both secured with DIN clips. You will need Citroën release keys — product code CT22UV01, CT22PE01 or the universal PSA set PC5-83. Price: three to six pounds.

Step by step

Switch off the ignition completely.

Insert the release keys into the narrow slots on either side of the radio unit.

Push the keys in until you feel the locking mechanism release (audible click).

Push the keys slightly apart while pulling the radio forwards.

Pull the unit out five to ten centimetres.

Read the serial number label. Quadlock connector (RD4): There is a Quadlock plug with a locking lever at the back. Turn the lever up before pulling the connector out.

Reading the serial number

On the Blaupunkt RD4 the BP serial number is on a white label on the top or side:

Format: BP followed by fourteen digits — e.g. BP730098728824
Sometimes the label starts with 815BP — in that case use the part from BP onwards

On the Clarion RD3 the serial number is on the side label and starts with C7 followed by ten digits.

On the VDO RD3 the format varies — note down all characters including hyphens.

Entering the code

Once "CODE" appears on the display:

Press preset 1 repeatedly until the first digit of your code is correct (0→9 cyclically).

Preset 2 for the second digit.

Preset 3 for the third digit.

Preset 4 for the fourth digit.

Hold the AS button or MODE button for two seconds to confirm. The radio starts immediately after a correct entry.

Locked out after an incorrect code?

After several incorrect attempts "CODE" disappears from the display.

Leave the ignition on (accessories switched on, engine off).

Wait thirty to sixty minutes without operating the radio.

After the waiting time "CODE" reappears.

Now enter the correct code. Permanent lockout: Too many incorrect attempts in a row leads to permanent unusability. Never guess a code at random.

RD4 and vehicle options in the C4 I

As in all PSA models, the RD4 also manages vehicle notifications and service warnings. If you replace the radio with a unit from another car, a session with PSA DiagBox is necessary to correctly pair the new unit with the C4 I's BSI.

Ordering the radio code

With the BP serial number of your RD4 you can request the Citroën C4 I radio code straight away. Delivery by email.

Order your Citroën C4 I radio code via RadioCodeLookup.com →

Other Citroën generations

Frequently asked questions

Most Citroën C4 I examples (2004-2010) have a Blaupunkt RD4 as the standard radio. Early models from 2004-2006 sometimes still had a Clarion or VDO RD3. The optional navigation system is the Magneti Marelli RT3 — that system does not have a traditional radio code.

Yes, the RD4 is hardware-identical. PSA (Peugeot-Citroën Automobiles) used the same Blaupunkt unit in virtually all models of both brands. On Citroën too, the serial number starts with BP followed by fourteen digits.

The serial number is on a white label on the top or side of the RD4 unit, visible once removed from the dashboard. On the Blaupunkt RD4 it always starts with BP.

Use Citroën release keys (product code CT22UV01 or CT22PE01). Insert them into the narrow slots on either side of the radio, push until they click, and pull the radio forwards. The C4 I has a standard DIN mounting.

Press presets 1 to 4 repeatedly to set each digit. Confirm by holding the AS button or MODE button for two seconds. This is exactly the same procedure as on Peugeot models with the same RD4.

Need a Citroën radio code?

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Laatst bijgewerkt: 2026-04-10