U0155Średni
Utrata komunikacji z modułem wspomagania (EPS)
Komunikacja sieciowa
Sprawdź szczegóły →P1625
KrytycznyImmobilizer system error or unexpected reset of the engine control module (ECM). Manufacturer code signaling a key authorization problem or central controller disturbance.
OBD-II (EN): Immobilizer System Error or Unexpected ECM Reset
Code P1625 most often indicates a problem with the immobilizer system – the vehicle cannot identify the key and blocks engine start. Depending on the manufacturer, it may also mean an unexpected ECM controller reset caused by electrical interference. Due to the complexity of the anti-theft system and inter-module communication, diagnostics by an experienced mechanic with a professional scanner are recommended.
Symptoms
- Flashing or constantly lit immobilizer warning light on the dashboard - Inability to start the engine (engine does not start despite key/button rotation) - Engine stalls immediately or a few seconds after starting - Immobilizer or anti-theft error message on the vehicle display - In case of ECM fault: unstable engine operation, random shutdowns, Check Engine light
Possible causes
- Damaged or worn transponder in the key (no response to antenna signal) - Malfunction of the immobilizer module/controller or ring antenna at the ignition switch - Communication problem between immobilizer and ECM (CAN/K-Line bus) - Unexpected ECM reset caused by electromagnetic interference (e.g., non-standard electronics, aftermarket audio/alarm) - Discharged or damaged battery causing loss of ECM authorization data - Damage to the wiring harness or corrosion of immobilizer controller contacts
Affected systems
Immobilizer / system antykradzieżowyModuł sterujący silnikiem (ECM/PCM)Magistrala komunikacyjna CAN/K-LineSystem zapłonu i rozruchuInstalacja elektryczna
Related codes
B1000Wysoki
Moduł sterowania nadwoziem (BCM) — usterka wewnętrzna
Nadwozie
Sprawdź szczegóły →U0100Krytyczny
Utrata komunikacji z ECM (sterownik silnika)
Komunikacja sieciowa
Sprawdź szczegóły →Code P1625 appears in these brands
Go to messages and symptoms for your brand — there we analyze this code together with other typical alerts.
Does code P1625 require professional diagnostics?
The code alone is not enough. To find the cause, you need to read live data, check freeze frame conditions, and compare with vehicle behavior. Book a diagnostic session.