Immobilizer Transponder Authentication Failure
2018-2025 Fiat Cronos 1.3L I4 Flex Firefly 🇨🇦
Description
The immobilizer detected a transponder signal but authentication failed. The key code does not match the stored code.
Symptoms
- Engine cranks but will not start
- Security light solid on
- Key rejected by system
Common Causes
- Key not programmed to this vehicle
- Immobilizer module lost key memory
- Aftermarket key with incorrect code
- Immobilizer control module failure
Diagnostic Steps
- Try all registered keys
- Check key programming status
- Attempt key relearn procedure
- Scan immobilizer module codes
- Verify VIN match in immobilizer
Repair Notes
Reprogram key to vehicle using manufacturer procedure. May require dealer tool.
Related Codes
Other Body Codes
- B0001Driver Frontal Stage 1 Deployment Control
- B0002Driver Frontal Stage 2 Deployment Control
- B0003Passenger Frontal Stage 1 Deployment Control
- B0004Passenger Frontal Stage 2 Deployment Control
- B0005Driver Knee Airbag Deployment Circuit
- B0006Passenger Knee Airbag Deployment Circuit
- B0007Rear Left Side Airbag Deployment Circuit
- B0008Rear Right Side Airbag Deployment Circuit
- B0009Rear Center Airbag Deployment Circuit
- B0010Driver Side Airbag Deployment
B0102 on Other Vehicles
Fiat 124 Spider
2017-2020 1.4L I4 Turbo
Fiat 126p Maluch
1973-2000 0.65L I2 Air-Cooled
Fiat 126p Maluch
1987-2000 0.7L I2 Air-Cooled
Fiat 500
2012-2019 1.4L I4
Fiat 500 Abarth
2012-2019 1.4L I4 Turbo
Fiat 500 BR
2011-2020 1.4L I4 Flex Fire Evo
Fiat 500 PL
2007-2025 1.0L I3 Hybrid FireFly 70
Fiat 500 PL
2007-2025 1.2L I4 Fire 69
Common Questions
What does code B0102 mean on a 2018-2025 Fiat Cronos?
B0102 stands for "Immobilizer Transponder Authentication Failure". The immobilizer detected a transponder signal but authentication failed. The key code does not match the stored code.
What are the symptoms of B0102 on a Fiat Cronos?
Common symptoms of B0102 include: Engine cranks but will not start, Security light solid on, Key rejected by system.
What causes B0102 on a 2018-2025 Fiat Cronos?
Common causes of B0102 include: Key not programmed to this vehicle, Immobilizer module lost key memory, Aftermarket key with incorrect code, Immobilizer control module failure.