01
What the BSI does, and why it fails
The BSI is a small computer that most drivers never see but every driver relies on. It stores the immobiliser pairing and vehicle identification data, and it controls the electrics that make the car usable day to day.
BSI units fail for the same reasons other modules do: water ingress, voltage spikes from a flat battery or a jump-start mistake, corrosion, and component failure inside the unit. On some models the BSI sits in a vulnerable position under the scuttle or behind the glovebox, where leaks reach it first.
02
The BSI families we work with
Peugeot and Citroen BSIs come from several manufacturers, and each family stores its data differently. The most common families we handle are Continental, Johnson Controls, Magneti Marelli, Siemens and Valeo units.
Rather than promise the world, we check your specific module: the part number on the BSI tells us which family it belongs to and what is possible. If your unit is one we can help with, we will say so; if it is not, we will tell you straight and point you to the realistic alternative.
03
How the work is done
Every BSI job starts with a diagnostic check to confirm the module is genuinely the fault rather than a wiring issue, a sensor or something simpler. If the BSI checks out as the problem, the work follows the same careful sequence as our ECU cloning: read the original data, verify it, and write it to a suitable replacement unit.
Because the immobiliser pairing and vehicle data are copied across, the replacement BSI works with your existing keys and the vehicle keeps its original settings. Nothing is reprogrammed or changed; the data is simply moved across. Cloning needs both modules: you send us your original unit and the replacement, which must be exactly the same part - check the part number matches before you buy.
04
An honest note on coverage
BSI work is offered on the common Peugeot and Citroen BSI families only. Some units are encrypted or hardware-locked in ways that prevent a clean read, and a few are bound to dealer-only systems. We check your specific module first and confirm honestly what is possible before any work is agreed.
05
Areas covered
Kent Eco Tuning is a local, independent specialist based in Medway. The mobile service covers Chatham, Rochester, Gillingham, Strood, Rainham and the wider Medway towns, along with Maidstone, Ashford, Dartford, Gravesend, Canterbury, Thanet and across Kent. BSI work needs bench time, so you can post your module in to us, or we'll come to you. We also cover body modules on other makes - see Body Module Services.
06
Peugeot & Citroen BSI FAQs
07
Will a replacement BSI work with my existing keys?
Yes. Because the immobiliser data and vehicle settings are cloned across, the replacement BSI recognises your existing keys and the vehicle behaves as it did before. You should not need new keys or dealer reprogramming.
08
Is BSI work the same as remapping?
No. Remapping changes the engine calibration to improve performance or economy. BSI work copies the existing body-module data unchanged onto a replacement unit. The two are separate services, although the same diagnostic-first approach and bench equipment are used.
09
Can every BSI be cloned?
No. BSI work is offered on the common Peugeot and Citroen families only. Some units are encrypted or hardware-locked in ways that prevent a clean read. We always check your specific module and confirm honestly before quoting.
10
Can you do a BSI reset?
Yes, on the covered families. A BSI reset or virgin restore is part of the work where the fault calls for it, and the bench equipment also reads pin codes and writes VIN data on those units. The five covered families are Continental, Johnson Controls, Magneti Marelli, Siemens and Valeo - we check your specific module first and confirm what is possible.