Immobilizer Antenna Ring Circuit
2018-2025 Fiat Cronos 1.3L I4 Flex Firefly
Description
Malfunction in the immobilizer antenna ring (transponder receiver coil) around the ignition lock cylinder or start button.
Symptoms
- Intermittent no-start
- Security light on
- Key sometimes not recognized
- Works with key held in specific position
Common Causes
- Faulty antenna ring coil
- Wiring damage from steering column work
- Connector loose
- Coil winding open or shorted
Diagnostic Steps
- Measure antenna ring resistance
- Inspect connector at steering column
- Check wiring from antenna to immobilizer module
- Test with oscilloscope for signal
Repair Notes
Replace immobilizer antenna ring. Ensure connector is fully seated after steering column work.
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
B0103 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 B0103 mean on a 2018-2025 Fiat Cronos?
B0103 stands for "Immobilizer Antenna Ring Circuit". Malfunction in the immobilizer antenna ring (transponder receiver coil) around the ignition lock cylinder or start button.
What are the symptoms of B0103 on a Fiat Cronos?
Common symptoms of B0103 include: Intermittent no-start, Security light on, Key sometimes not recognized, Works with key held in specific position.
What causes B0103 on a 2018-2025 Fiat Cronos?
Common causes of B0103 include: Faulty antenna ring coil, Wiring damage from steering column work, Connector loose, Coil winding open or shorted.