Radio code Citroën C5 I

The Citroën C5 I stood out at launch thanks to its unconventional hydrodynamic suspension and its long-distance comfort. Less comfortable is the moment the radio locks after a battery change — and the C5 gives you little warning: the display shows CODE and waits silently for the correct entry.

The Citroën C5 I (2001–2008) is part of the PSA group (Peugeot-Citroën-Automobiles) and shares its radio platform with the Peugeot 407 and 307. In most cases the radios are identical — only the brand on the housing may differ.

RD3 — the base radio in the early C5 I models. Supplied by Clarion or by VDO (Siemens VDO). The Clarion variant has a serial number starting with C7; the VDO variant uses its own Siemens format.

RD4 — the most common radio in the later C5 I and in higher trim levels. Supplied by Blaupunkt, recognisable by the BP serial number. The RD4 has several sub-variants but the code procedure is the same for all of them.

RT3 — the Magneti Marelli navigation option, a double-DIN unit. The RT3 has no standalone radio code — it is linked to the car via VIN and requires PSA DiagBox for recoding in the event of a radio problem.

The RD3 and RD4 activate their security on every power interruption:

• A battery change or flat battery
• Disconnecting the battery for maintenance
• Replacing a fuse in the radio circuit

The display shows "CODE". The radio refuses any other function until the correct code has been entered.

The serial number is on a sticker on the left or right side of the radio unit.

• RD3 Clarion: starts with C7, 12 characters in total, e.g. C70000001234
• RD4 Blaupunkt: starts with BP, 14 characters in total, e.g. BP730098728824

You'll need to slide the radio out a little to reach the sticker. The C5 sometimes has a slightly more deeply recessed radio than some smaller Citroëns — keep this in mind when choosing your release keys.

The RD3 and RD4 sit in a standard DIN bracket with internal spring clips. You'll need DIN release keys.

Step by step:

Once you have the four-digit radio code:

As with the Peugeot 307, the RD4 in the C5 I locks out permanently after several incorrect code attempts. There is no wait timer and no self-recovery. Once permanently locked, only a Citroën dealer with PSA DiagBox can unlock the radio — and even that doesn't always work.

The RD3 sometimes allows a little more leeway in the number of attempts, but the same rule applies here: never enter the code on a guess.

Does your C5 I have the RT3 navigation? Then the system is VIN-linked to the car. After an ordinary battery change (the radio stays in the same car), the RT3 starts up normally without asking for a code.

If an RT3 from another car has been fitted, recoding via PSA DiagBox is required.

In many cases the C5 II (2008+) still used an RD4 in its early years, but later switched to other systems. If you have a C5 II, check the year of manufacture and the radio model on the front panel.

With the C7 or BP serial number of your C5 I radio, you can request the official unlock code directly online.

Order your Citroën C5 I radio code via RadioCodeLookup.com →