What does code P1621 mean?

Q: What does code P1621 mean?

Immobilizer System Fault. P1621 on a Mazda means the engine control module (ECM) has detected a fault within the immobilizer system, which is the anti-theft network that verifies the key before allowing the engine to start. The ECM stores this code when it cannot complete a valid key authentication handshake with the immobilizer control module or when the transponder signal is missing or invalid.

DTC codes / Mazda codes / P1621

P1621 · MazdaImmobilizer System Fault

P1621 on a Mazda means the engine control module (ECM) has detected a fault within the immobilizer system, which is the anti-theft network that verifies the key before allowing the engine to start. The ECM stores this code when it cannot complete a valid key authentication handshake with the immobilizer control module or when the transponder signal is missing or invalid.

SystemPowertrain

Code typeMazda specific

SeverityMedium

Fix difficultyProfessional

AreaComputer and output circuits

Guidance is general and written for Mazda vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.