EDC15C7 Immo Off: Fiat, Alfa Romeo and Lancia 1.9 / 2.4 JTD ECU Immobilizer Removal

The Bosch EDC15C7 controls the first-generation JTD common-rail diesels: Fiat Punto, Brava/Bravo, Marea, Multipla, Stilo and Doblo 1.9 JTD, Alfa Romeo 145/146, 156, 166 and GT 1.9/2.4 JTD, Lancia Lybra, Kappa and Thesis. These cars are now 20 years old and Body Computer failures are common, which is why EDC15C7 immo off remains one of the top searches among our immo off files.

How the immobilizer works

Fiat Code 2 stores the key transponder data in the Body Computer (BSI). On each start the BSI sends a code to the engine ECU; if the answer does not match, the injectors stay closed. The engine cranks, fuel pressure is normal, but there is no combustion. Typical causes: a dead or water-damaged Body Computer, a used ECU from another car, or a lost Code Card with all keys gone.

Immo off, virgin or keys?

• Immo off — the ECU no longer waits for the Body Computer. Engine starts with any key. Best for a dead BSI, engine transplants and workshop test engines.
• Virgin file — resets the ECU so it learns the code of your own BSI at the first start. Best when installing a used EDC15C7 into a car whose BSI works.
• Key programming — with a working BSI and the Code Card (or a tool that reads the BSI EEPROM), new keys can be added without touching the ECU.

Reading the EDC15C7

Good news for a 2000s ECU: the EDC15C7 reads over OBD with KESS V2, Galletto, MPPS and similar tools (K-line). On the bench, KTAG and Flex read the 29F400/29F800 flash. The immobilizer data lives in the flash itself on this generation, so the OBD read contains everything needed.

1. Battery on a charger, ignition on, read the full flash and save it as the original.
2. Check the label: Bosch number 0 281 0xx xxx and Fiat part number 46 xxx xxx / 55 xxx xxx. The software must match the file you buy.
3. Write the immo off file with the same tool; wait for the checksum confirmation.

After the write

The engine starts immediately. The Code lamp may stay on because the BSI still expects a reply — it has no effect on running, emissions or diagnostics. If the car still does not start, look at the fuel pressure sensor and the rail pressure regulator; on a 1.9 JTD a weak lift pump produces the same crank-no-start symptom.

Files and part numbers

Over 160 EDC15C7 references are listed under EDC15C7, filterable by Fiat, Alfa Romeo and Lancia. Related units: the EDC15C5 (Peugeot/Citroen HDi) and EDC15C3 (Renault) use different files. If yours is not listed, the file request form prepares the immo off version from your own read.