B0101
Immobilizer Transponder Signal Not Detected
1992-1998 BMW 325i E36 2.5L I6 M50 🇨🇦
High SeverityBody
Description
The immobilizer system cannot detect the transponder signal from the key. The engine will not start.
Symptoms
- Engine cranks but will not start
- Security light flashing
- Key symbol on dashboard
- No-start condition
Common Causes
- Dead key battery (smart key)
- Faulty transponder chip in key
- Damaged antenna ring around ignition
- Interference from other transponder keys
- Key handle cracked exposing transponder to damage
Diagnostic Steps
- Try different registered key
- Hold key closer to ignition/start button
- Check for key battery (if applicable)
- Test antenna ring with known-good key
- Scan immobilizer codes
Repair Notes
Replace key battery or have new key programmed. Replace antenna ring if faulty.
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
- B0010Driver Side Airbag Deployment
- B0011Driver Side Airbag Deployment Circuit Open
- B0012Driver Side Airbag Deployment Circuit Short to Ground
- B0013Driver Side Airbag Deployment Circuit Short to Battery
B0101 on Other Vehicles
Common Questions
What does code B0101 mean on a 1992-1998 BMW 325i E36?
B0101 stands for "Immobilizer Transponder Signal Not Detected". The immobilizer system cannot detect the transponder signal from the key. The engine will not start.
What are the symptoms of B0101 on a BMW 325i E36?
Common symptoms of B0101 include: Engine cranks but will not start, Security light flashing, Key symbol on dashboard, No-start condition.
What causes B0101 on a 1992-1998 BMW 325i E36?
Common causes of B0101 include: Dead key battery (smart key), Faulty transponder chip in key, Damaged antenna ring around ignition, Interference from other transponder keys, Key handle cracked exposing transponder to damage.